541 results
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2. A direct mass spectrometry method for cannabinoid quantitation in urine and oral fluid utilizing reactive paper spray ionization.
- Author
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Borden, Scott A., Saatchi, Armin, Palaty, Jan, and Gill, Chris G.
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SALIVA , *MASS spectrometry , *ELECTROSPRAY ionization mass spectrometry , *URINE , *LIQUID chromatography-mass spectrometry , *DETECTION limit , *CATIONS - Abstract
A direct mass spectrometry method utilizing reactive paper spray ionization was developed for sensitive cannabinoid quantitation in biofluid matrices. The ca. 2-minute sample measurements used on-paper derivatization to significantly increase paper spray mass spectrometry (PS-MS) positive ion mode sensitivity while minimizing sample preparation steps. Calibrations demonstrate high linearity, with R2 > 0.99 for (−)-trans-Δ9-tetrahydrocannabinol (THC) in oral fluid and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) in urine. The limit of detection and lower limit of quantitation were 0.78 and 10 ng mL−1 for THC in oral fluid and 1.3 and 10 ng mL−1 for THC-COOH in urine, respectively. THC-COOH levels measured by reactive PS-MS in seven spiked human urine samples showed bias of −9.4 to 5.9%, and percent difference values of −16.8 to 9.8% in comparison with a reference LC-MS method. Based upon the method simplicity, validation experiments, sensitivity, and rapidity, we conclude that reactive PS-MS has potential applications for rapid cannabinoid drug testing in urine and oral fluid. [ABSTRACT FROM AUTHOR]
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- 2022
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3. Electronic structure and metal–metal communication in (CpM)2(as-indacene) and (CpM)2(s-indacene) (M = Mn, Fe, Co, Ni) complexes: a DFT investigationThis paper is dedicated to an outstanding chemist, our friend Didier Astruc, on the occasion of his 65th birthday.
- Author
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Garland, Maria Teresa, Kahlal, Samia, Carey, Desmond Mac-Leod, Arratia-Pérez, Ramiro, Manríquez, Juan Manuel, and Saillard, Jean-Yves
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ELECTRONIC structure , *AROMATIC compounds , *TRANSITION metal complexes , *DENSITY functionals , *CATIONS , *LIGANDS (Chemistry) , *MOLECULAR orbitals , *S-Indacene - Abstract
DFT calculations with full geometry optimization have been performed on the series (CpM)2(as-indacene) and (CpM)2(s-indacene) (M = Mn, Fe, Co, Ni), as well as on the cations of the Fe, Co and Ni complexes. The compounds where M = Fe and Ni (as-indacene series) and M = Mn, Fe and Co (s-indacene series) were found to possess closed-shell ground states. In the mixed-valent cations as well as in the other open-shell species, the degree of metal–metal communication and the participation of the ligand into the spin density were evaluated. In general, the larger the total electron number, the larger the metal–metal communication and ligand participation to the frontier orbitals. [ABSTRACT FROM AUTHOR]
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- 2011
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4. Synthesis and properties of glycerylimidazolium based ionic liquids: a promising class of task-specific ionic liquidsThis paper was published as part of the themed issue of contributions from the Green Solvents - Progress in Science and Application conference held in Friedrichshafen, September 2008.
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Bellina, Fabio, Bertoli, Alessandra, Melai, Bernardo, Scalesse, Francesca, Signori, Francesca, and Chiappe, Cinzia
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ORGANIC synthesis , *IONIC liquids , *IMIDAZOLES , *CATIONS , *SUSTAINABLE chemistry , *GLYCERIN , *CATALYSIS , *PALLADIUM catalysts - Abstract
A series of task-specific ionic liquids (TSILs) based on glycerylimidazolium cations have been prepared by reaction of 1-chloropropanediol, a compound obtainable from glycerol (a widely available and in-expensive waste product), with the appropriate base (1-H-imidazole, 1,2-dimethylimidazole and 1-methyl-1-H-imidazole). The reaction of 3-(1H-imidazol-1-yl)propane-1,2-diol with chloroalkanes, bromoalkanes and alkyl mesylates gave the corresponding salts which were characterized. The possibility to use these ILs in palladium catalyzed reactions was evaluated, evidencing good catalyst stability and a high recyclability. [ABSTRACT FROM AUTHOR]
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- 2009
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5. Integrated strong cation exchange/capillary reversed-phase liquid chromatography/on-target digestion coupled with mass spectrometry for identification of intact human liver tissue proteinsThis paper is part of an Analystthemed issue highlighting Chinese science, with guest editor Mengsu (Michael) Yang.Electronic supplementary information (ESI) available: spreadsheet of protein identification data. See DOI: 10.1039/b803388a
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Mingxia Gao, Wenjia Yu, Yang Zhang, Guoquan Yan, Chunhui Deng, Pengyuan Yang, and Xiangmin Zhang
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PROTEINS , *CHROMATOGRAPHIC analysis , *CATIONS , *BILIARY tract - Abstract
We present a comprehensive method for proteome analysis that integrates both intact protein separation and proteolytic fragment characterization mass spectrometric approaches. Strong cation exchange chromatography (SCX) was used as the first separation dimension and capillary reversed-phase liquid chromatography (cRPLC) was integrated as the second separation dimension. Fractions from SCX were collected offline and loaded onto cRPLC. Effluents from cRPLC were directly deposited onto the MALDI target plates and further digested by using a rapid on-probe tryptic digestion technique. This approach minimizes the amount of time and extensive labor required for traditional in-solution digestion followed by exhaustive sample cleanup and transfer. MALDI-TOF/TOF was used for subsequent analyses. The sensitivity of on-target digestion is showed by analyzing 0.07 ng of myoglobin, 0.07 ng of cytochrome c and 0.7 ng BSA. The high efficiency of the overall system was demonstrated by the analysis of intact proteins extracted from normal human liver tissue. In total, 458 proteins were identified, which proved the system's promising potential for analysis and application in proteomics. [ABSTRACT FROM AUTHOR]
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- 2008
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6. Bulky phosphazenium cation catalysis for dehydrative condensation of phosphoric acid with alcoholsThis paper was presented at the Japan/ UK Green Sustainable Chemistry Symposium at the 87th Chemical Society of Japan Annual meeting, March 2007.Electronic supplementary information (ESI) available: Experimental details; 1H and 13C NMR spectra for all products. See DOI: 10.1039/b707974e
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Akira Sakakura, Mikimoto Katsukawa, Takaomi Hayashi, and Kazuaki Ishihara
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CHEMISTRY , *CATIONS , *SURFACE chemistry , *CHEMISTRY associations - Abstract
A metal-free phosphazenium cation-catalyzed direct dehydrative condensation of phosphoric acid with alcohols has been developed for the environmentally benign synthesis of phosphoric acid monoesters. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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7. Direct synthesis and structural characterisation of tri- and tetra-nuclear silver metallaknotanes by self-assembly approachThis paper is dedicated to Professor Andrew B. Holmes FRS on the occasion of his 65th birthday.CCDC 701605 and 701606. For crystallographic data in CIF or other electronic format see DOI: 10.1039/b815580a
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Julien Bourlier, Abdelaziz Jouaiti, Nathalie Kyritsakas-Gruber, Lionel Allouche, Jean-Marc Planeix, and Mir Wais Hosseini
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SILVER compounds , *MOLECULAR self-assembly , *QUINOLINE , *LIGANDS (Chemistry) , *BIRTHDAYS , *CHEMICAL reactions , *CATIONS - Abstract
The combination of ligands based on two quinoline units acting as primary coordinating sites connected by tetra- or penta-ethyleneoxy fragments behaving as secondary interaction sites leads spontaneously in a one-pot reaction to the formation of tri- and terta-nuclear metalla-organic knots in the presence of silver cation. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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8. Novel antimony phosphates with enlarged birefringence induced by lone pair cations.
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Hu, Mei, Wang, Jialong, Tuerhong, Nuerbiye, Zhang, Zhiyuan, Jing, Qun, Chen, Zhaohui, Yang, Yonglei, and Lee, Ming-Hsien
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BIREFRINGENCE ,ANTIMONY ,BAND gaps ,ELECTRON pairs ,CATIONS - Abstract
Phosphates, whose obvious disadvantage is the relatively small birefringence, can be overcome by the introduction of post-transition metal cations containing stereochemically active lone-pair electrons. In this paper, two new compounds were successfully explored in the A–Sb–P–O system, i.e. Cs
2 Sb3 O(PO4 )3 (CsSbPO) and (NH4 )2 Sb4 O2 (H2 O)(PO4 )2 [PO3 (OH)]2 (NH4 SbPOH). Transmission spectra show that CsSbPO has a surprising transmission range with a UV cutoff edge of 213 nm. First-principles calculations show that both compounds have a wide band gap (5.02 eV for CsSbPO and 5.30 eV for NH4 SbPOH) and enlarged birefringence (Δn = 0.034@1064 nm for CsSbPO and Δn = 0.045@1064 nm for NH4 SbPOH). The results of real-space atom-cutting investigations show that the distorted [SbOx ] polyhedra originating from the asymmetric lone pair electrons give the main contribution to the total birefringence and overcome the disadvantage of small birefringence of phosphates but maintain wide transition windows. [ABSTRACT FROM AUTHOR]- Published
- 2024
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9. Influence of the organic cation on the formation of hexahalotechnetates: X-ray, thermal and comparative analyses of non-covalent interactions.
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Novikov, Anton P., Zagidullin, Karim A., Volkov, Mikhail A., German, Konstantin E., Nevolin, Iurii M., and Grigoriev, Mikhail S.
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THERMAL analysis ,WATER of crystallization ,TECHNETIUM compounds ,TRP channels ,CATIONS ,COMPARATIVE studies - Abstract
In this work, we have reviewed non-covalent interactions in technetium hexahalide compounds and obtained eight new compounds of the Cat
n TcHal6 type, where Cat = dimethylammonium, tetramethylammonium, caffeinium, benzothiazolium, nicotinamidium, and pyrazolium, and Hal = Cl, Br. SCXRD studies were carried out for new compounds. In some compounds, halide anions and/or crystallization water were present. In the compounds obtained, an essential influence on the formation of structures and crystal packing is exerted by the molecules of crystallization water and halide ions. Diethylammonium and nicotinamidium compounds, whose structures do not contain other ions and contain sufficiently strong non-covalent interactions, best bind hexahalotechnetates. π-Stacking interactions, anion–π interactions, and halogen bonds were found in the structures. The percentage contribution of the H⋯Hal/Hal⋯H interactions in the transition from fluorine to bromine in TcHal6 2− anions decreases, while the contribution of interactions of other types increases. The greatest variety of interactions in anions is observed for compounds of caffeinium and nicotinamidium with TcBr6 2− . The paper considers the processes of thermolysis of some new and previously known Catn TcHal6 compounds with various cations. It is shown that the thermal stability of the compounds is only due to the properties of the organic cation and does not depend on the nature of the halogen. The proposed stages of the process of thermolysis of the TcHal6 2− anion, accompanied by the reduction of technetium to metal, have been established. [ABSTRACT FROM AUTHOR]- Published
- 2023
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10. Exceptional structural diversity of hybrid halocuprates(I) with methylammonium and formamidinium cations.
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Belikova, Daria E., Fateev, Sergey A., Khrustalev, Victor N., Marchenko, Ekaterina I., Goodilin, Eugene A., Wang, Shenghao, and Tarasov, Alexey B.
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METHYLAMMONIUM ,CATIONS ,OPTICAL properties ,PHOTOLUMINESCENCE - Abstract
Hybrid halocuprates(I) are nowadays the subject of intensive studies as promising materials for various optoelectronic applications. This class of materials is characterized by wide structural diversity enabled by a great variety in the size and shape of organic cations. Therefore, the study of composition–structure–property relationships is a key step for the rational design of new halocuprate materials with desired properties. In this paper, we comprehensively studied MABr/CuBr and FABr/CuBr systems (MA
+ = methylammonium and FA+ = formamidinium) and established the existence of five novel phases (namely, MACu2 Br3 , FA2 [Cu4 Br6 ], MACuBr2 , FACuBr2 , and FA3 CuBr4 ) related to four different structural types and three distinct A+ : Cu+ stoichiometries (A+ = MA+ /FA+ ). The optical properties of the discovered phases are studied by absorption and low-temperature photoluminescence spectroscopy. Based on a crystal–chemical analysis, we explained a unique structural diversity of the MA- and FA-based bromocuprates, as well as revealed new structure–property relationships. [ABSTRACT FROM AUTHOR]- Published
- 2023
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11. Reductive hydrothermal conversion of uranyl oxalates into UO2+x monitored by in situ XANES analyses.
- Author
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Benarib, Sofian, Munoz, Maëva, Kieffer, Isabelle, Hazemann, Jean-Louis, Dacheux, Nicolas, and Clavier, Nicolas
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OXALATES ,CHEMICAL systems ,NUCLEAR fuels ,OXIDATION states ,URANIUM ,IONS ,CATIONS - Abstract
Hydrothermal conversion of actinide oxalates has recently gained attention as an innovative fabrication route for nuclear fuels but has remained mainly limited to tetra- or tri-valent cations. We report herein the reductive conversion of mixtures of uranyl and oxalate ions into UO
2+x oxides under mild hydrothermal conditions (T = 250 °C). A multi-parametric study first led to specifying the optimal conditions in terms of pH, oxalate/U ratio and duration to provide a quantitative precipitation of uranium in the hyper-stoichiometric dioxide form with pH = 0.8; R = noxalate /nU = 3, and t = 72 hours. Particularly, pH was evidenced as a key parameter, with 3 different compounds obtained over a range of only 0.4 units. The mechanism leading to the formation of UO2+x was then investigated thanks to an in situ XANES study. Analysis of the supernatant showed that U(VI) was quickly reduced into U(IV) thanks to the presence of oxalates and/or their decomposition products in solution, following first-order kinetics. Tetravalent uranium was then hydrolysed, leading to the precipitation of UO2+x as the only crystalline phase. This study thus demonstrates that the hydrothermal conversion of actinide oxalates into oxides is an extremely versatile tool that can be implemented in a large variety of chemical systems, particularly in terms of the oxidation state of the cations initially present in solution. [ABSTRACT FROM AUTHOR]- Published
- 2024
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12. Crystalline products of bromoantimonate(III) oxidation by Br2 in the presence of different cations: diversity of structural types and patterns of halogen bond systems.
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Bondarenko, Mikhail A., Novikov, Alexander S., Abramov, Pavel A., Sokolov, Maxim N., and Adonin, Sergey A.
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HALOGENS ,QUANTUM chemistry ,CATIONS ,THERMOGRAVIMETRY ,X-ray diffraction ,OXIDATION - Abstract
Reactions of bromoantimonate(III) containing solutions with Br
2 in the presence of different organic cations result in structurally highly diverse crystalline products readily forming halogen bonds (XBs). Herein, we add six new compounds to this palette using 1,n-bis(3-methylpyridinium)- or (4-methylpyridinium)alkane dications; the complexes were characterized using X-ray diffraction and thermogravimetric analysis (TGA). Further, we discuss all previous results in this field, including quantum chemistry investigation of the features of XBs in such compounds. [ABSTRACT FROM AUTHOR]- Published
- 2024
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13. Co(III) complexes of the pentadentate NHC ligand PY4Im: carbene-induced trans influences and the non-disappearing 13C NMR peak.
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Ismael, Fouad, Fleming, Cassandra L., Christopher, Timothy D., Söhnel, Tilo, Zhou, Yuchen, Krenske, Elizabeth H., Gahan, Lawrence R., and Blackman, Allan G.
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CARBON ,X-rays ,GEOMETRY ,CATIONS - Abstract
Co(III) complexes of the N-heterocyclic carbene ligand PY4Im (PY4Im = (1,3-bis(bis(2-pyridyl)methyl)imidazol-2-ylidene)) having the general formula [(PY4Im)Co(X)](ClO
4 )n (X = NCMe; n = 3: OH− , N3 − , NCS− , ONO− , F− ; n = 2: O2 CO2− , n = 1; (N3 − )3 , n = 0) were prepared and structurally characterised. X-ray structural data are consistent with the presence of a trans influence due to the coordinated carbene carbon, and this is also supported by computational results.13 C NMR spectra of the complexes did not display peaks corresponding to the carbene carbon, except in the case of the [(PY4Im)Co(O2 CO)]+ cation, where a peak at δ = 170.21 ppm was observed. However, HMBC spectra allowed indirect determination of the chemical shifts of the carbene carbon in the remaining complexes, owing to the geometry of the PY4Im ligand. Calculated13 C chemical shifts for the complexes showed very good agreement with the experimental values for all but the carbene carbon atoms in all cases. [ABSTRACT FROM AUTHOR]- Published
- 2024
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14. Multiresponsive luminescent sensing behaviour of a tetraimidazole ligand and its 3D Cd(II) metal–organic frameworks.
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Wu, Ye-Feng, Cheng, Jia-Jun, Jiang, Tao, Ma, Yu-Chen, Kou, Jia-Lei, Cheng, Guo-Feng, Hu, Xiu-Li, Tang, Xiao-Yan, Ma, Yun-Sheng, Yin, Wen-Yu, and Cheng, Hong-Jian
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LIGANDS (Chemistry) ,SINGLE crystals ,AQUEOUS solutions ,ANIONS ,CATIONS ,COORDINATION polymers - Abstract
The detection of excess toxic anions or cations in an aqueous solution through various fluorescent materials such as organic or inorganic fluorescent materials has aroused significant interest recently. Herein, a new tetraimidazole ligand 1,3-bis(1-imidazolyl)-5-[3,5-bis(1-imidazolyl)-phenoxymethyl]-benzene (timpb) and its two Cd(II) metal–organic frameworks {[Cd
2 (1,4-bdc)2 (timpb)]·5.5(H2 O)}n (1) (1,4-benzenedicarboxylic acid = 1,4-H2 bdc) and {[Cd2 (4,4′-bpdb)2 (timpb)]·(MeCN)·2.5(H2 O)}n (2) (4,4′-biphenyldicarboxylic acid = 4,4′-H2 bpdb) were synthesized. Through X-ray single crystal diffraction analysis, 1 can be considered as a 2-fold interpenetrating pillared-bilayer framework formed by linking [Cd2 (1,4-bdc)4 ]n layers with pairs of timpb ligands, whereas 2 exhibits a 2-fold interpenetrating 3D honeycombed framework formed by linking [Cd(4,4′-bpdb)]n chains with timpb ligands. The solid-state luminescent properties of timpb, 1 and 2 at ambient temperature were also investigated. Moreover, timpb acted as a potential luminescent sensor for the detection of cations Fe3+ or Cu2+ and the anion Cr2 O7 2− , whereas 1 displayed high sensitivity toward the cation Fe3+ and anion Cr2 O7 2− . [ABSTRACT FROM AUTHOR]- Published
- 2024
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15. On the mechanism of sp2 C–H borylation using ortho-N-substituted pyridinium cations.
- Author
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Slesarchuk, Nikita, Ma, Enlu, Miranda-Pizarro, Juan, Heikkinen, Sami, Schollmeyer, Dieter, Nieger, Martin, Vasko, Petra, and Repo, Timo
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BORYLATION ,CATIONS ,SUBSTRATES (Materials science) ,CATALYSIS ,PROTONS - Abstract
ortho-N-Substituted pyridinium cations with the weakly coordinating anion [B(C
6 F5 )4 ]− have been studied and crucial structural features in the sp2 C–H borylation catalysis of 3-methylthiophene have been identified. The electron-deficiency of the aromatic core of the cation is essential for activity together with accessible protons. The spectroscopic yield of the borylation of 3-methylthiophene with catecholborane (CatBH) was optimized up to 86% and the method was further applied to other substrates such as N-alkylbenzenes. A mechanistic DFT study revealed the rate-limiting step in the catalysis to be the liberation of molecular H2 (ΔG‡ = 27.5 kcal mol−1 ), whereas the overall reaction was found to be exergonic by 5.1 kcal mol−1 . [ABSTRACT FROM AUTHOR]- Published
- 2024
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16. Crystal growth and cation order of Ni3−xCoxB2O6 oxyborates.
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Sofronova, Svetlana, Moshkina, Evgeniya, Chernyshev, Artem, Vasiliev, Aleksandr, Maximov, Nikolai G., Aleksandrovsky, Aleksandr, Andryushchenko, Tatyana, and Shabanov, Aleksandr
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CRYSTAL growth ,TRANSITION metal ions ,LATTICE constants ,CATIONS ,SINGLE crystals - Abstract
A series of single crystals of Ni
3−x Cox B2 O6 compounds with the kotoite structure and with different concentrations of transition metal ions (x = 0; 0.19; 0.6; 0.93 and 2) were obtained. The lattice parameters and atomic coordinates were determined using X-ray diffraction. The theoretical calculations using the WIEN2k package predict that nickel ions tend to occupy the 4f crystallographic position, while cobalt ions tend to occupy the 2a crystallographic position. The study of the diffuse scattering spectra and comparison of the Racah parameters for the compounds Ni3 B2 O6 and Co2 NiB2 O6 provides experimental evidence that nickel ions occupy crystallographic position 4f. [ABSTRACT FROM AUTHOR]- Published
- 2024
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17. Opposite effects of cations in enhancing and suppressing nucleation in the pathological crystallization of gout.
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Da, Anqi, Ren, Aijun, Cheng, Rong, Zhang, Xingde, Pan, Yonglan, Ou, Chunyan, Fu, Tingming, and Liu, Yonghai
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NUCLEATION ,GOUT ,CATIONS ,CRYSTALLIZATION ,DISTRIBUTION (Probability theory) ,IONIC strength - Abstract
In this paper, we focused on the influence of common serum cations on monosodium urate monohydrate (MSUM) crystal nucleation determined from cumulative probability distributions (CPDs) of solute crystal nucleation events as a function of time. Surprisingly, with an increase in the concentration of additive ions, striking "opposite effects" were observed for cations, enhancing nucleation at first followed by suppressing nucleation at physiological pH and ionic strength. This enhancing nucleation phenomenon cannot be explained based on colloidal theories or simple descriptors, such as ion size, but it is consistent with the cationic efficacy for inducing an increase in the proportion of growth units of MSUM. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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18. Discriminatory behavior of a rhodamine 6G decorated mesoporous silica based multiple cation sensor towards Cu2+ and Hg2+vis-à-vis Al3+, Cr3+ and Fe3+: selective removal of Cu2+ and Hg2+ from aqueous media
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Singha, Debdas, Pal, Ananya, Uyama, Hiroshi, Roy, Partha, and Nandi, Mahasweta
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RHODAMINES ,MESOPOROUS silica ,PINK ,X-ray powder diffraction ,ALDEHYDE derivatives ,CATIONS - Abstract
Selective identification of metal ions as well as their removal is possible when a sensing unit is anchored to a solid support. In this paper, functionalized mesoporous silica with a pendant rhodamine 6G moiety (R6FMS) has been obtained by successive grafting of an aldehyde derivative of bisphenol A followed by rhodamine 6G over a 3-aminopropyl anchored mesoporous silica framework. The materials have been characterized by powder X-ray diffraction, nitrogen sorption and electron microscopy studies, FT-IR and solid state MAS NMR spectral studies, and thermal analysis. In ethanol, the colorless silica material gives pink coloration in the presence of Al
3+ , Cr3+ , Fe3+ and Cu2+ which is also clearly evident from the generation of an absorption peak at 525 nm. Upon excitation at 500 nm, the fluorescence intensity of the probe increases by 36-, 17-, 40- and 89-fold in the presence of Al3+ , Cr3+ , Fe3+ and Cu2+ ions, respectively. This suggests that R6FMS is a colorimetric and fluorescent chemosensor for these cations in ethanol. However, when the solvent is changed from ethanol to water, it becomes a selective chemosensor only for Cu2+ and Hg2+ , by the generation of a pink color and strong fluorescence at ca. 550 nm, thereby discriminating the trivalent cations. Cations induce the opening of the spirolactam ring resulting in pink coloration and strong fluorescence. The quantum yield and lifetime of the probe have been increased considerably in the presence of these cations in ethanol as well as in aqueous media. The detection limit values for these cations range from 10−6 to 10−8 M. R6FMS has been used to remove Hg2+ and Cu2+ from their aqueous solution with a maximum adsorption capacity of 35 mg g−1 and 148 mg g−1 for Cu2+ and Hg2+ , respectively. [ABSTRACT FROM AUTHOR]- Published
- 2021
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19. Scalable droplet-based radiosynthesis of [18F]fluorobenzyltriphenylphosphonium cation ([18F]FBnTP) via a "numbering up" approach.
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Lu, Yingqing, Collins, Jeffrey, Lin, Kuo-Shyan, and van Dam, R. Michael
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MYOCARDIAL perfusion imaging ,POSITRON emission tomography ,RADIOCHEMICAL purification ,CATIONS ,FLUORIDE varnishes - Abstract
The [
18 F]fluorobenzyltriphenylphosphonium cation ([18 F]FBnTP) has emerged as a highly promising positron emission tomography (PET) tracer for myocardial perfusion imaging (MPI) due to its uniform distribution in the myocardium and favorable organ biodistribution demonstrated in preclinical studies. However, a complex and low-efficiency radiosynthesis procedure has significantly hindered its broader preclinical and clinical explorations. Recently, Zhang et al. developed a pinacolyl arylboronate precursor, enabling a one-step synthesis process that greatly streamlines the production of [18 F]FBnTP. Building upon this progress, our group successfully adapted the approach to a microdroplet reaction format and demonstrated improved radiosynthesis performance in a preliminary optimization study. However, scaling up to clinical dose amounts was not explored. In this work, we demonstrate that scale-up can be performed in a straightforward manner using a "numbering up" strategy (i.e. performing multiple droplet reactions in parallel and pooling the crude products). The resulting radiochemical yield after purification and formulation was high, up to 66 ± 1% (n = 4) for a set of experiments involving pooling of 4 droplet reactions, accompanied by excellent radiochemical purity (>99%) and molar activity (339–710 GBq μmol−1 ). Notably, we efficiently achieved sufficient activity yield (0.76–1.84 GBq) for multiple clinical doses from 1.6 to 3.7 GBq of [18 F]fluoride in just 37–47 min. [ABSTRACT FROM AUTHOR]- Published
- 2024
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20. Can cage-like cations function as antagonistic ions towards pentazolate anions?
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Jiang, Tianyu, Xia, Honglei, Zhang, Wenquan, Cai, Ziwu, Song, Siwei, and Liu, Tianlin
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ANIONS ,CATIONS ,IONS ,TRP channels ,BLOOD substitutes - Abstract
Although numerous non-metallic pentazolate (cyclo-N
5 − ) salts have been synthesized and investigated, no cyclo-N5 − salt containing cage-like cations has been reported to date. To identify how cage-like cations impact the structures and properties of cyclo-N5 − salts, we synthesized and examined two cyclo-N5 − salts (C10 H18 N6 and C6 H14 N12 ) based on cage-like cations. Furthermore, the structures and performances of these cyclo-N5 − salts were compared. The results suggest that the cyclo-N5 − salts based on cage-like cations possess good insensitivity (IS > 40 N, FS > 360 J), which provides a good idea for developing new energetic salts with low sensitivity. Furthermore, we compared C6 H14 N12 with chain-like cationic pentazolate salt based on a similar structure and reported that C6 H14 N12 demonstrated improved density and detonation performance. This result indicates that selecting cage-like cations as antagonistic ions to cyclo-N5 − anions may be an improved choice compared to chain-like cations having similar structures. [ABSTRACT FROM AUTHOR]- Published
- 2024
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21. Subphthalocyanines as fluorescence sensors for metal cations.
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Alfred, Mary Angelia, Lang, Kamil, Kirakci, Kaplan, Stuzhin, Pavel, Zimcik, Petr, Labuta, Jan, and Novakova, Veronika
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ALKALINE earth metals ,FLUORESCENCE yield ,FLUORESCENCE ,CATIONS ,STRUCTURE-activity relationships ,BINDING constant - Abstract
Subphthalocyanines (SubPcs) and their aza-analogues (SubTPyzPzs) are fluorophores with strong orange fluorescence emission; however, their sensing ability towards metal cations remains uncharted. To fill this gap, we have developed an efficient method for introducing aza-crown moieties at the axial position of SubPcs and SubTPyzPzs to investigate the structure–activity relationship for sensing alkali (Li
+ , Na+ , K+ ) and alkaline earth metal (Ca2+ , Mg2+ , Ba2+ ) cations. SubPcs showed better photostability than SubTPyzPzs and even a commonly utilized dye, 6-carboxyfluorescein. Selectivity toward metal cations was driven by the size of the aza-crown, irrespective of the counter anion. The stoichiometry of binding was found to be 1 : 1 in all cases, and the interaction between SubPcs and cations was characterized by the corresponding apparent binding constants (Ka ). Notably, an unusually strong interaction of all sensoric SubPcs with Ba2+ compared to other studied cations was demonstrated. The role of the surrounding environment, i.e. the addition of water or methanol, in sensing cations is shown in detail as well. Selectivity towards K+ over Na+ was demonstrated in aqueous media with SubPcs bearing the 1-aza-6-crown-18 moiety in Tween 80 micelles. In this case, a 5-fold increase of the fluorescence quantum yield was observed upon binding K+ ions. The high brightness, photostability, and sensing activity in aqueous media make SubPc macrocycles promising fluorophores for metal cation sensing. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
22. Optical and scintillation properties of hybrid manganese(II) bromides with formamidinium and acetamidinium cations.
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Fateev, Sergey A., Kozhevnikova, Vladislava Y., Kuznetsov, Kirill M., Belikova, Daria E., Khrustalev, Victor N., Goodilin, Eugene A., and Tarasov, Alexey B.
- Subjects
OPTICAL properties ,MANGANESE ,SCINTILLATORS ,CATIONS ,ATTENUATION coefficients ,RADIOLUMINESCENCE - Abstract
In recent years, hybrid manganese(II) halides (HMHs) have attracted wide attention due to their impressive optical properties, low toxicity, and facile synthetic processibility. Being effective reabsorption-free phosphors, these compounds demonstrate the potential to be used as low-cost solution-processable scintillators. However, most of the HMHs studied to date contain bulk organic cations and, as a result, are characterized by low density and low X-ray stopping power. For this reason, we studied manganese(II) bromides with compact organic cations such as formamidinium (FA
+ ) and acetamidinium (AcA+ ). In particular, we synthesized four new phases, two of which are characterized by octahedral coordination of manganese ions ((FA)MnBr3 and (AcA)MnBr3 ) and red emission, whereas the other two have tetrahedrally coordinated Mn2+ ions ((FA)3 MnBr5 and (AcA)2 MnBr4 ) and green emission. Photoluminescence (PL) and radioluminescence measurements demonstrated high PL quantum yields and reasonable scintillation light yields of acetamidinium-based compounds. In addition, unlike most known HMH-based scintillators, the discovered materials have a relatively high density due to the small fraction of the volume occupied by organic cations, so their X-ray attenuation coefficients are comparable to the well-known oxide scintillators. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
23. Cation vacancy-boosted BaZnB4O8:xEu3+ phosphors with high quantum yield and thermal stability for pc-WLEDs.
- Author
-
Liu, Naijia, Chen, Nianmin, Wang, Yunjian, Kong, Juanjuan, and Wang, Zhe
- Subjects
THERMAL stability ,LIGHT emitting diodes ,RIETVELD refinement ,OPTICAL devices ,CATIONS ,CATIONIC polymers - Abstract
Achieving high luminescent quantum yield and thermal stability of phosphors simultaneously remains challenging, yet it is critical for facilitating high-power white light emitting diodes (WLEDs). Herein, we report the design and preparation of the layered structure BaZnB
4 O8 :xEu3+ (0.10 ≤ x ≤ 0.60) red phosphors with high quantum yield (QY = 76.5%) and thermal stability (82.8%@150 °C) by the traditional solid-state reaction method. The results of XRD and Rietveld refinement show that the presence of Eu3+ ions at Ba2+ sites causes the formation of cation (Zn2+ /Ba2+ ) vacancies in the lattice. The PL and PL decay results reveal that the quenching concentration of BZBO:xEu3+ phosphors is as high as 50%, and the lifetime remains unchanged with Eu3+ concentration due to the unique structure of the host and the cation vacancies generated by the heterovalent substitution. Furthermore, on a 395 nm near-UV chip, a pc-WLED device with exceptional optical performance (CCT = 4415 K, CRI = 92.1) was realized using the prepared BZBO:0.50Eu3+ as a red phosphor. Simple synthesis and excellent performance parameters suggest that the reported BaZnB4 O8 :xEu3+ phosphors have promising applications in high-power pc-WLEDs. At the same time, it also indicates that cationic vacancy engineering based on heterovalent ion substitution is a potential strategy for improving luminescence quantum yield and thermal quenching performance. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
24. Ordering by cation replacement in the system Na2−xLixGa7.
- Author
-
Yu, Chia-Chi, Prots, Yurii, Ormeci, Alim, Krnel, Mitja, Schmidt, Marcus, Akselrud, Lev, Wagner, Frank R., Grin, Yuri, and Baitinger, Michael
- Subjects
SPACE groups ,ICOSAHEDRA ,CRYSTAL structure ,SOLID solutions ,TRP channels ,CATIONS ,ALKALI metals - Abstract
Samples of the pseudo-binary system Na
2−x Lix Ga7 (x ≤ 1) were synthesized from the elements at 300 °C in sealed Ta ampoules or by the reaction of Na2 Ga7 with LiCl. The peritectic formation temperature decreases with increasing Li content from 501(2) °C (x = 0) to 489(2) °C (x = 1). The boundary compositions Na2 Ga7 and Na1 Li1 Ga7 crystallize with different structure types related by a group–subgroup relation. While the Na-rich compositions (x ≤ 0.5) represent a substitutional solid solution (space group Pnma), the Li-rich compositions feature an unconventional replacement mechanism in which Li atoms occupying interstitial positions induce vancancies at the Na positions (space group Cmce). The crystal structure of Na1 Li1 Ga7 (a = 8.562(1) Å, b = 14.822(2) Å, c = 11.454(2) Å; Z = 8) was determined from X-ray single-crystal diffraction data, and reveals an anionic framework comprising 12-bonded Ga12 icosahedra and 4-bonded Ga atoms, with alkali–metal atoms occupying channels and cavities. The arrangement of cations makes NaLiGa7 a new structure type within the MgB12 Si2 structure family. Band structure calculations for the composition NaLiGa7 predict semiconducting behavior consistent with the balance [Na+ ]2 [Li+ ]2 [(Ga12 )2− ][Ga– ]2 , considering closo Wade clusters [(12b)Ga12 ]2− and Zintl anions [(4b)Ga]− . Susceptibility measurements indicate temperature-independent diamagnetic behavior. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
25. Synthesis and supramolecular organization of the iodide and triiodides of a polycyclic adamantane-based diammonium cation: the effects of hydrogen bonds and weak I⋯I interactions.
- Author
-
Mezentsev-Cherkes, Ivan A., Shestimerova, Tatiana A., Medved'ko, Aleksei V., Kalinin, Mikhail A., Kuznetsov, Alexey N., Wei, Zheng, Dikarev, Evgeny V., Vatsadze, Sergey Z., and Shevelkov, Andrei V.
- Subjects
HYDROGEN bonding ,ADAMANTANE derivatives ,IODIDES ,REFLECTANCE spectroscopy ,CATIONS ,CRYSTAL structure - Abstract
A careful selection of organic and inorganic components enables the production of unusual structure types with promising practical properties by facile syntheses. In this paper, we describe novel supramolecular architectures comprising organic adamantane-like divalent building blocks and iodide or polyiodide anions. Highly acidic conditions facilitated the formation of a doubly protonated organic ligand out of 5,7-dimethyl-1,3-diazaadamantane that generates three different crystal structures with inorganic counterions. In these structures, cationic substructures are constructed by transforming neutral organic ligands into [(C
10 N2 H20 )I]+ or [(C10 N2 H20 )(H2 O)]2+ cations, which crystallize with charge-compensating iodine-based anions of different complexities. All three crystal structures are characterized by various noncovalent forces, ranging from strong (N)H⋯I, (O)H⋯I, and (N)H⋯O hydrogen bonds to secondary and weak I⋯I interactions. Raman and diffuse reflectance spectroscopy as well as DFT calculations were employed to describe the electronic structures and optical properties of new supramolecular architectures, with particular attention to the role of non-covalent interactions. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
26. Reactions of carbene-stabilized borenium cations.
- Author
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Lam, Jolie, Cao, Levy L., Farrell, Jeffrey M., and Stephan, Douglas. W.
- Subjects
CATIONS ,CHEMICAL adducts ,VEINS ,PYRAZOLYL compounds ,SALTS ,SPECIES - Abstract
In this paper we probe the reactivity of the borenium cations [C
3 H2 (NCH2 C6 H4 )(NCH2 Ph)BH][B(C6 F5 )4 ] 2 and [C3 H2 (NCH2 C6 H4 )2 B][B(C6 F5 )4 ] 3. The reactions of 2 with cyclohexene or 3,3-dimethyl-1-butene gave the alkyl-aryl borenium salts [PhCH2 (CHN)2 CCH2 C6 H4 BR][B(C6 F5 )4 ] (R = Cy 4, CH2 CH2 tBu 5) while the corresponding reactions with diphenylacetylene, 1-hexyne and 1-phenyl-1-propyne gave the aryl–alkenyl borenium cation salts [PhCH2 (CHN)2 CCH2 C6 H4 BC(R1 )C(H)R2 ][B(C6 F5 )4 ] (R1 = R2 = Ph 6, R1 = H, R2 = C4 H9 7, R1 = Me, R2 = Ph 8a, R1 = Ph, R2 = Me 8b). In contrast, the reaction of 2 with ethynyldiphenylphosphane or 2-vinylpyridine lead to the formation of the adducts, [PhCH2 (CHN)2 CCH2 C6 H4 B(H)P(Ph2 )CCH][B(C6 F5 )4 ] 9, [PhCH2 (CHN)2 CCH2 C6 H4 B(H)NC5 H4 C(H)CH2 ][B(C6 F5 )4 ] 10, respectively, while the more bulky donor H2 C=C(Ph)PMes2 gave 1,2-hydroboration of the phosphinoalkene affording [PhCH2 (CHN)2 CCH2 C6 H4 BCH2 CH(Ph)PMes2 ][B(C6 F5 )4 ] 11. In another vein of reactivity, one or two equivalents of the FLP, PtBu3 /B(C6 F5 )3 is shown to react with 3 to give the zwitterionic borenium-borate species [C2 H2 (NCH(BC(CHNCH2 C6 H4 )2 )C6 H4 )(NCH(B(C6 F5 )3 )C6 H4 )CB] 12 and the anionic bis-borate species[tBu3 PH][C2 H2 (NCH(B(C6 F5 )3 )2 C6 H4 )2 CB] 13. The implications of these findings are discussed. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
27. Optical enhancement of highly efficient organic–inorganic oxyfluoride red phosphors via the cation co-doping strategy.
- Author
-
Liu, Xiaoyi, Cheng, Haiming, Wang, Hu, Wen, Zhu, Liu, Guixia, Liu, Shengda, Li, Dan, Wang, Jinxian, Yu, Wensheng, and Dong, Xiangting
- Subjects
PHOSPHORS ,INTERIOR lighting ,CATIONS ,OPTICAL properties ,ENERGY dissipation ,LUMINESCENCE spectroscopy ,TERBIUM ,OPTICAL communications - Abstract
Herein, a new organic cationic matrix [N(CH
3 )4 ]3 MoO3 F3 suitable for Mn4+ doping was constructed. Due to the large steric hindrance of N[CH3 ]4 + (TMA), charge compensation defects can be effectively prevented in the heterovalent Mn4+ -doping process, and a high IQE (91.05%) was obtained. Through the cation co-doping strategy, Mg2+ /Zn2+ /Li+ cations were introduced into the Mo6+ cationic site, which improved the crystallinity of the matrix and reduced energy losses, so as to improve luminescence intensity, QE, thermal stability, water stability and other spectral properties. Meanwhile, [N(CH3 )4 ]2 TiF6 :Mn4+ phosphors with the same TMA organic cation and equivalent Mn4+ doping were synthesized for comparison, and the effects of the Mg2+ cation co-doping strategy on the spectral properties of phosphors with different matrix types (fluoride/oxyfluoride) and substitution types (equivalent/non-equivalent) were analyzed. These findings provide the basis for the preparation of new luminescent materials. Furthermore, according to the optical properties exhibited by these phosphors, they are packaged into WLED devices with excellent photoelectric properties, which are suitable for indoor lighting and display fields. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
28. Phosphinoborenium cations stabilized by N-heterocyclic carbenes: synthesis, structure, and reactivity.
- Author
-
Kaniewska-Laskowska, Kinga, Ordyszewska, Anna, Wojnowski, Tomasz, Halenka, Hanna, Czapla, Marcin, Chojnacki, Jarosław, and Grubba, Rafał
- Subjects
NUCLEAR magnetic resonance spectroscopy ,CARBENES ,DENSITY functional theory ,CATIONS ,X-ray diffraction - Abstract
Phosphinoborenium cations stabilized by N-heterocyclic carbenes (NHCs) were synthesized via the reaction of bromo(phosphino)boranes with NHCs. Their structures were investigated by heteronuclear magnetic resonance spectroscopy, X-ray diffraction, and density functional theory calculations. They possess a planar trigonal boron center directly bonded with the pyramidal phosphanyl group (PR
2 ) and can be treated as cationic phosphinoboranes. The reactivity of the selected NHC-phosphinoborenium cation was tested toward AuCl·SMe2 and Ph2 PCl. In both reactions, the titled compound acted as a phosphido group donor under heterolytic cleavage of the P–B bond. Control experiments with parent phosphinoborane emphasized differences between the reactivity of low-coordinate neutral and cationic species with P–B functionality. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
29. Synthesis of fluorinated aminium cations coupled with carborane anions for use as strong one-electron oxidants.
- Author
-
Davidson, Jillian J., Gunther, S. Olivia, Leong, Derek W., and Ozerov, Oleg V.
- Subjects
OXIDIZING agents ,ANIONS ,CATIONS ,OXIDATION ,OXIDATION-reduction reaction - Abstract
Synthesis of a series of hydrocarbon-soluble triarylamines bearing F, CF
3 , and Br substituents showing quasi-reversible redox events in the 0.59–1.32 V range is reported. Chemical oxidation of the amines was carried out with 0.5PhI(OAc)2 /Me3 SiX/Na[RCB11 Cl11 ] (X = Cl or OTf, R = H or Me), and a few aminium salts were isolated as pure solids. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
30. In silico -screened cationic dipeptides from scallop with synergistic gelation effect on ι-carrageenan.
- Author
-
Xu SQ, Han YT, Yan JN, Jiang XY, Du YN, and Wu HT
- Subjects
- Amino Acid Sequence, Amino Acids analysis, Animals, Computer Simulation, Female, Male, Peptide Fragments, Rheology, Tandem Mass Spectrometry, Trypsin, Carrageenan chemistry, Cations, Dipeptides chemistry, Gels chemistry, Pectinidae metabolism
- Abstract
In this paper, some cationic dipeptides from scallop (Patinopecten yessoensis) male gonads (SMGs), which can synergistically gel with ι-carrageenan (ι-C), were screened by the in silico approach. Fourteen protein sequences of SMGs were obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and nano liquid chromatography-mass spectrometry/mass spectrometry (nanoLC-MS/MS) analysis and were then hydrolyzed via in silico simulation. A total of 414 sequences were obtained with 56 duplicates, half of which were positively charged at pH 7. Among the cation sequences, 171 had good water solubility, including two amino acids (Lys and Arg). The molecular weight analysis of the cationic water-soluble sequences showed that 0.2-0.3 kDa accounted for the highest proportion. Based on the obvious synergistic effect of Lys and ι-C, 11 Lys-containing dipeptides, including Ser-Lys (SK), Thr-Lys (TK), Trp-Lys (WK), Ala-Lys (AK), Leu-Lys (LK), Gly-Lys (GK), Val-Lys (VK), Cys-Lys (CK), Asn-Lys (NK), Phe-Lys (FK), and Met-Lys (MK), were finally screened out to study gelation with ι-C. It was found that the dipeptides/ι-C formed firm gels except WK/ι-C. The values of the storage modulus (G') of 11 dipeptides/ι-C were investigated by a rheometer. The G' of 8 dipeptides/ι-C was higher than 1000 Pa. These results indicated that the in silico-screened dipeptides from SMGs can form composite gels with ι-C, which can be used for the design and development of functional hydrogels.
- Published
- 2021
- Full Text
- View/download PDF
31. Contents list.
- Subjects
CATIONS ,PHOSPHONATES - Published
- 2019
- Full Text
- View/download PDF
32. Significant effects of mixed cations on the morphology and photochemical activities of alkali–metal-antimony (Na,K)Sb3O7.
- Author
-
Wei, Donglei, Yang, Xifeng, Liu, Yushen, Kim, Joo Hyun, Park, Sung Heum, Seo, Hyo Jin, and Lee, Bo Ram
- Subjects
ALKALI metals ,CATIONS ,OXIDATION-reduction reaction ,BAND gaps ,LIGHT absorption ,HYDROTHERMAL synthesis ,ALKALI metal ions ,PHOTODEGRADATION - Abstract
Oxide semiconductors with mixed-valence states generally exhibit excellent optoelectronic and photochemical properties due to facile charge transfer in redox reactions. In this work, we investigate the effects of mixed alkali on the optical absorption, luminescence spectra and photocatalytic abilities of (Na
1−x Kx )Sb3 O7 nanoparticles. All the samples are fabricated using a simple one-step hydrothermal method. The structural studies show that the largest substitution of K+ ions in (Na1−x Kx )Sb3 O7 is at x = 0.3. In hydrothermal synthesis, the mixed arrangement of K+ and Na+ in (Na1−x Kx )Sb3 O7 has an influence on the crystal shape of particles. NaSb3 O7 develops into a regular cube shape. With the increase of K+ ions in (Na1−x Kx )Sb3 O7 , the edges and corners of the cube are further ground off, resulting in irregularly spherical particles. This mixed-alkali antimonite belongs to a p-type indirect allowed transition semiconductor, and the optical band gap is 2.71 eV (x = 0.3). The intrinsic luminescence of NaSb3 O7 is detected at 540 nm, which is nearly quenched in Na0.7 K0.3 Sb3 O7 . It is demonstrated that the substitution of K+ in NaSb3 O7 significantly increases the photodegradation of RhB solutions. There are two types of Sb cations, i.e., Sb5+ and Sb3+ mixed in the structure. The improved photocatalysis is attributed to the charge mediators between Sb5+ /Sb3+ couples. The experiment shows that co-doping cations in antimonite oxides may be one of the strategies to improve photochemical properties. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
33. Germanium- and tin-bridged diazulenylmethyl cations: effects of group 14 elements on the structure and properties of π-extended cations.
- Author
-
Murai, Masahito, Ito, Mako, Takahashi, Satoshi, and Yamaguchi, Shigehiro
- Subjects
GROUP 14 elements ,CHEMICAL stability ,CATIONS ,TIN ,SILICON alloys - Abstract
Diazulenylmethyl cations bridged with a germanium and tin moiety were synthesized. In these cations, the nature of these elements has impacts on the chemical stability and photophysical properties. Upon aggregation, these cations exhibit absorption bands in the near-infrared region, which are slightly blue-shifted compared to those of silicon-bridged congeners. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
34. New ionic liquids based on systemic acquired resistance inducers combined with the phytotoxicity reducing cholinium cation.
- Author
-
Kukawka, R., Czerwoniec, P., Lewandowski, P., Pospieszny, H., and Smiglak, M.
- Subjects
IONIC liquids ,CATIONS - Abstract
Systemic acquired resistance (SAR) is one of the most promising ways to support plants in the fight against viruses. Using this approach biological or chemical factors interact with plants and stimulate their immune system against infections before infection occurs. This paper presents synthesis, physical properties, phytotoxicity and SAR induction efficacy of 15 ionic liquids, derivatives of SAR inducers paired with the cholinium cation, an essential nutrient for organisms. SAR induction efficacy tests were performed on tobacco Nicotiana tabacum var. Xanthi infected by tobacco mosaic virus (TMV). [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
35. Application of nonmetallic frustrated cations in the activation of small molecules.
- Author
-
Kaniewska-Laskowska, Kinga, Czapla, Marcin, Chojnacki, Jarosław, and Grubba, Rafał
- Subjects
SMALL molecules ,DENSITY functional theory ,CATIONS - Abstract
The concept of nonmetallic frustrated cations has been used in small molecule activation. The in situ generated ambiphilic phosphinoborinium cation activated phenyl isocyanate, diisopropylcarbodiimide, and acetonitrile under very mild conditions without any catalyst, yielding single-, double-, or mixed-activation products. Furthermore, the mechanisms of the reactions of the phosphinoborinium cation with small molecules were elucidated using density functional theory calculations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Synthesis and characterization of heterometallic rings templated through alkylammonium or imidazolium cations.
- Author
-
Alotaibi, Rajeh, Booth, Amy, Little, Edmund, Brookfield, Adam, Achari, Amritroop, Lockyer, Selena J., Timco, Grigore A., Whitehead, George F. S., Vitórica-Yrezábal, Iñigo J., Chilton, Nicholas F., Nair, Rahul R., Collison, David, and Winpenny, Richard E. P.
- Subjects
ELECTRON paramagnetic resonance spectroscopy ,EXCITED states ,MAGNETIC measurements ,CATIONS ,ELEMENTAL analysis - Abstract
We report the synthesis and structural characterization of a series of heterometallic rings templated via alkylammonium or imidazolium cations. The template and preference of each metal's coordination geometry can control the structure of heterometallic compounds, leading to octa-, nona-, deca-, dodeca-, and tetradeca-metallic rings. The compounds were characterized by single-crystal X-ray diffraction, elemental analysis, magnetometry, and EPR measurements. Magnetic measurements show that the exchange coupling between metal centres is antiferromagnetic. EPR spectroscopy shows that the spectra of {Cr
7 Zn} and {Cr9 Zn} have S = 3/2 ground states, while the spectra of {Cr12 Zn2 } and {Cr8 Zn} are consistent with S = 1 and 2 excited states. The EPR spectra of {(ImidH)-Cr6 Zn2 }, {(1-MeImH)-Cr8 Zn2 }, and {(1,2-diMeImH)-Cr8 Zn2 } include a combination of linkage isomers. The results on these related compounds allow us to examine the transferability of magnetic parameters between compounds. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
37. Syntheses, structures, photoelectric properties and photocatalysis of iodobismuthate hybrids with lanthanide complex cations.
- Author
-
Zhang, Jiahua, Yang, Xiao, Ren, Taohong, and Jia, Dingxian
- Subjects
RARE earth metals ,BAND gaps ,HYDROGEN bonding interactions ,PHOTOCATALYSIS ,CATIONS ,CATALYTIC activity - Abstract
New iodobismuthate hybrids with lanthanide complex counter cations, [Ln(DMF)
8 ][Bi2 I9 ] (Ln = La (1), Eu (2)) and [Tb(DMF)8 ]2 [Bi2 I9 ]2 (3) (DMF = N,N-dimethylformamide), were prepared using solvated Ln(III) complexes formed in situ as structure-directing agents. The dimeric [Bi2 I9 ]3− anion moieties of compounds 1–3 are aggregated by two slightly twisted BiI6 octahedra through face-sharing mode. The different crystal structures of 1–3 are due to the different I⋯I and C–H⋯I hydrogen bond interactions. Compounds 1–3 have narrow semiconducting band gaps at 2.23, 1.91 and 1.94 eV, respectively. Under Xe light irradiation, they exhibit steady photocurrent densities that are 1.81, 2.10 and 2.18 times higher than that of pure BiI3 , respectively. Compounds 2 and 3 exhibited higher catalytic activities than 1 in the photodegradation of organic dyes CV and RhB, which are attributed to the stronger photocurrent response derived from the redox cycles of Eu3+ /Eu2+ and Tb4+ /Tb3+ . [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
38. Ionothermal carbonization of sugarcane bagasse in imidazolium tetrachloroferrate ionic liquids: effect of the cation on textural and morphological properties.
- Author
-
Aldroubi, Soha, El-Sakhawy, Mohamed, Kamel, Samir, Hesemann, Peter, Mehdi, Ahmad, and Brun, Nicolas
- Subjects
BAGASSE ,IONIC liquids ,CARBONIZATION ,SUGARCANE ,BENZYL group ,CATIONS - Abstract
The valorization of abundant agrowastes into chemicals and advanced materials is of key importance in the context of the circular bioeconomy and biorefinery. Herein, we report the ionothermal carbonization (ITC) of sugarcane bagasse, a fibrous residue made of lignocellulose, to engineer advanced carbonaceous materials, namely ionochars. We prepared a series of imidazolium tetrachloroferrate ionic liquids (IL) bearing modular substituents, e.g., alkyl chains with different lengths or benzyl groups. The effect of the cation on both textural and morphological properties is highlighted. Ionochars with high specific surface area (up to 800 m
2 g−1 ), tuneable pore volume (up to 0.8 cm3 g−1 ), singular nanostructures and adjustable CO2 uptake/retention were obtained. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
39. General synthesis of CoCeMOx trimetallic oxides via a cation exchange reaction for the oxygen evolution reaction.
- Author
-
Huang, Xianggang, Wang, Xin, Liu, Yingxin, Hou, Yan, Li, Chengjin, Cai, Mingyang, Gu, Hongwei, and Cao, Xueqin
- Subjects
HYDROGEN evolution reactions ,OXYGEN evolution reactions ,EXCHANGE reactions ,VALENCE fluctuations ,ION exchange (Chemistry) ,OXIDES ,CATIONS - Abstract
Cobalt-based spinel oxides are considered potential candidates for the oxygen evolution reaction (OER) due to their abundant valence changes and promising electrochemical activity, but their low intrinsic activity hinders their practical applications. Herein, we synthesize a series of CoCeMO
x (M = Zn, Ni, Ru, Er, Mg, Mn, Sn) derived from CoCeM coordination-driven self-assembled aggregates (CDSAAs) using a general ion exchange and subsequent calcination method. Interestingly, CoCeMOx exhibit different morphologies from porous nanospheres, particle-stacked nanospheres, to hollow nanospheres as the third metal element is altered. Markedly, CoCeZnOx porous nanospheres (PNs) exhibit the best OER performance. The XPS results reveal that the existence of CeO2 and Zn2+ ions significantly increased the Co2+ /Co3+ ratio and the content of oxygen vacancies in Co3 O4 . Furthermore, Co2+ can be used as highly reactive sites to form CoOOH and the high content of oxygen vacancies can optimize the oxygen-containing intermediate adsorption energy, both of which can effectively improve the OER performance. Therefore, well-designed CoCeZnOx PNs demonstrate high OER activity with a lower overpotential (η = 333 mV) than that of commercial RuO2 (344 mV) in 10 mA cm−2 , a Tafel slope of 98 mV dec−1 , and a long-term durability of 45 h. This work may provide some inspiration for the design of trimetallic oxide nanomaterials. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
40. A new copper chloride chain by supported hydrogen bonding.
- Author
-
Tuikka, Matti, Kersen, Ülo, and Haukka, Matti
- Subjects
COPPER chlorides ,HYDROGEN bonding ,CATIONS ,POLYMER research ,CHLORIDES - Abstract
In the current paper we introduce a new type of Cu–Cl polymer ([H
2 bipip]2+ [CuCl3 ]2− )n . In this polymer the trigonal CuCl3 units are covalently linked via chloride bridges. The structure is supported by the bipiperidinium cation ([H2 bipip]2+ ) via hydrogen bonds. The cation plays an essential role in formation of the polymeric structure. The closely related piperazinium (H2 pip)2+ cation also leads to a hydrogen bonded assembly of CuCl3 ([H2 pip]2+ [CuCl3 ]2− ), but a covalently bound polymer was not obtained. [ABSTRACT FROM AUTHOR]- Published
- 2013
- Full Text
- View/download PDF
41. Preparation, photoluminescence and excited state properties of the homoleptic cluster cation [(W6I8)(CH3CN)6]4+.
- Author
-
Pachel, Florian, Frech, Philipp, Ströbele, Markus, Enseling, David, Romao, Carl P., Jüstel, Thomas, Scheele, Marcus, and Meyer, Hans-Jürgen
- Subjects
EXCITED states ,PHOTOLUMINESCENCE ,TRP channels ,ACETONITRILE ,CATIONS ,X-ray diffraction ,LIGANDS (Chemistry) - Abstract
Solvated tungsten iodide cluster compounds are presented with the homoleptic cluster cation [(W
6 I8 )(CH3 CN)6 ]4+ and the heteroleptic [(W6 I8 )I(CH3 CN)5 ]3+ , synthesized from W6 I22 in acetonitrile. Crystal structures were solved and refined on deep red single-crystals of [(W6 I8 )(CH3 CN)6 ](I3 )(BF4 )3 ·H2 O, [(W6 I8 )I(CH3 CN)5 ](I3 )2 (BF4 ), and on a yellow single-crystal of [W6 I8 (CH3 CN)6 ](BF4 )4 ·2(CH3 CN) on the basis of X-ray diffraction data. The structure of the homoleptic [(W6 I8 )(CH3 CN)6 ]4+ cluster is based on the octahedral [W6 I8 ]4+ tungsten iodide cluster core, coordinated by six apical acetonitrile ligands. The electron localisation function of [(W6 I8 )(CH3 CN)6 ]4+ is calculated and solid-state photoluminescence and its temperature depedence are reported. Additionally, photoluminescence and transient absorption measurements in acetonitrile are shown. Results of the obtained data are compared to compounds containing [(M6 I8 )I6 ]2− and [(M6 I8 )L6 ]2− (M = Mo or W; L = ligand) clusters. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
42. Influence of alkali metal cations on the formation of the heterobimetallic actinide tert-butoxides [AnM3(OtBu)7] and [AnM2(OtBu)6] (AnIV = Th, U; MI = Li, Na, K, Rb, Cs)
- Author
-
Lichtenberg, Andreas, Zegke, Markus, Nichol, Gary S., Raauf, Aida, and Mathur, Sanjay
- Subjects
ALKALI metals ,ALKALI metal ions ,SOLID solutions ,CATIONS ,SINGLE crystals ,URANIUM - Abstract
Heterobimetallic tert-butoxides of alkali metal cations with tetravalent actinide centers exhibit two distinctive structural motifs, [AnM
2 (Ot Bu)6 ] and [AnM3 (Ot Bu)7 ] (AnIV = Th, U and MI = Li, Na, K, Rb, Cs), evidently governed by the size of the alkali metal ions. Both [AnM3 (Ot Bu)7 ] AnM3 (AnIV = U, MI = Li; AnIV = Th, MI = Li, Na) and [AnM2 (Ot Bu)6 ] AnM2 (AnIV = U, MI = Na–Cs; AnIV = Th, MI = K–Cs) compounds are obtained in nearly quantitative yields by reacting actinide and alkali metal silyl amides with an excess of tert-butyl alcohol. The AnM3 complexes form a cubane-type coordination motif, whereas the AnM2 complexes display a geometry resembling two face-shared bipyramids. The sodium derivatives of thorium and uranium (ThNa3 and UNa2) allow the determination of the structural transition threshold as a function of the ratio of the ionic radii ri (AnIV )/ri (MI ). The AnM3 complexes are formed for ratios above 0.92 and the AnM2 type is formed for ratios below 0.87. All compounds are unambiguously characterized in both solution and solid states by NMR and IR spectroscopic studies and single crystal X-ray diffraction analyses, respectively. [ABSTRACT FROM AUTHOR]- Published
- 2023
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43. Mixed-halide copper-based perovskite R2Cu(Cl/Br)4 with different organic cations for reversible thermochromism.
- Author
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Elattar, Amr, Tsutsumi, Kosei, Suzuki, Hiroo, Nishikawa, Takeshi, Kyaw, Aung Ko Ko, and Hayashi, Yasuhiko
- Subjects
QUANTUM wells ,PEROVSKITE ,COPPER chlorides ,THERMOCHROMISM ,HALIDES ,X-ray diffraction measurement ,DIFFERENTIAL scanning calorimetry ,CATIONS - Abstract
Two-dimensional (2D) hybrid perovskites have exhibited multiple features owing to their multiple quantum well structure. Here, we show the synthesis and characterization of 2D mixed-halide Cu-based perovskite crystals, R
2 Cu(Cl/Br)4 , with three different alkyl chains, where R is methyl, butyl, or hexyl ammonium cations. Exfoliated perovskite flakes exhibit reversible thermochromism with changes in color darkness with temperature variation. Differential scanning calorimetry and temperature-dependent X-ray diffraction measurements reveal that the thermochromic behavior mechanism of R2 Cu(Cl/Br)4 depends on the nature of the alkyl chain. [ABSTRACT FROM AUTHOR]- Published
- 2022
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44. An unprecedented non-classical polyinterhalogen anion made of [I2Cl]− and I2 at the 2-(p-tolyl)selenopheno[2,3-b]pyridinium cation template.
- Author
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Aragoni, M. Carla, Podda, Enrico, Arca, Massimiliano, Pintus, Anna, Lippolis, Vito, Caltagirone, Claudia, Bartz, Ricardo H., Lenardão, Eder J., Perin, Gelson, Schumacher, Ricardo F., Coles, Simon J., and Orton, James B.
- Subjects
ANIONS ,SINGLE crystals ,TRP channels ,CRYSTAL structure ,CATIONS ,HYDROGEN bonding - Abstract
The reactivity between 2-(p-tolyl)selenopheno[2,3-b]pyridine (L) and ICl in MeCN is presented. Single crystal structure analysis revealed the formation of two distinct crystalline materials both featuring the protonated 2-(p-tolyl)selenopheno[2,3-b]pyridinium cation [HL]
+ . Colourless crystals were identified as the dihydrate salt [HL]Cl·2H2 O (1), and dark-red crystals as compound {[HL]+ [I2 Cl]− }3 ·1/2I2 (2) that features the peculiar presence of the rare non-classical [I2 Cl]− interhalide. Halogen Bonds (XBs) between the cocrystallized I2 molecule and [I2 Cl]− anions led to the novel overall discrete [I10 Cl4 ]4− H-shaped polyinterhalide formation, which is stabilized through hydrogen bonds (HBs) with the templating [HL]+ cations. The experimental observations are supported by extensive theoretical calculations at the DFT level that were employed to study the role played by non-covalent interactions in the formation of the presented unique polyinterhalide. [ABSTRACT FROM AUTHOR]- Published
- 2022
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45. Crystal and molecular structure of series of triphilic ionic liquid-crystalline materials based on the 1,2,4-triazolium cation.
- Author
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Riccobono, Alessio, Whitwood, Adrian C., Parker, Rachel R., Hart, Sam, Pace, Andrea, Slattery, John M., Pibiri, Ivana, and Bruce, Duncan W.
- Subjects
MOLECULAR structure ,CRYSTAL structure ,MOLECULAR crystals ,SPACE groups ,CATIONS ,ACETONE - Abstract
Results from the determination of sixteen X-ray single crystal structures are reported for a series of 3-(4-alkoxyphenyl)-5-perfluoroalkyl-2,4-dimethyl-1,2,4-triazolium salts with tetrafluoroborate, triflate or bistriflimide anions, in which the lengths of the alkoxy and perfluoroalkyl chains are varied systematically. On account of these cations having a hydrocarbon, fluorocarbon and ionic part, they are classified as triphilic. All of the tetrafluoroborate salts crystallised in the P2
1 /c space group, most as acetone solvates, while for the bistriflimide salts, four different space groups were found although all contained a P21 screw axis often with additional symmetry elements. Of the triflates, two crystallised in space groups with a P21 screw axis and two in P1¯. The organisation in the crystalline state tended to reflect the triphilic nature of the materials with cations and anions associating in repeating motifs, while the rest of the space was occupied by either hydrocarbon or fluorocarbon domains with only two exceptions. [ABSTRACT FROM AUTHOR]- Published
- 2022
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46. Structural principles of cation ordering and octahedral tilting in A-site ordered double perovskites: ferroelectric CaMnTi2O6 as a model system.
- Author
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Albrecht, Elisabeth K. and Karttunen, Antti J.
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PEROVSKITE ,CATIONS ,OCTAHEDRA - Abstract
We have used quantum chemical methods to study the structural principles and energetics of A-site ordered AA′B
2 O6 double perovskites. 33 combinations of A-site ordering and Glazer tilting have been systematically studied for the ferroelectric CaMnTi2 O6 model system. The used approach was able to predict the correct combination of A-site ordering and tilting of octahedra in comparison to the experimentally known CaMnTi2 O6 . The energy differences between the various combinations of A-site ordering and tilt systems show a large variation of tens of kJ mol−1 per formula unit, which suggests that the methodology used here can be used as a starting point for making reliable predictions on the structures of yet unknown A-site ordered double perovskites. The energy differences due to A-site ordering and octahedral tilting were larger compared to the energy difference arising from ferroelectric distortion in CaMnTi2 O6 . The energy differences between various hypothetical double perovskite structures could be explained by studying their structural characteristics in detail. The relative energies are closely correlated with the Mn–O distances and Mn coordination in the studied structures. [ABSTRACT FROM AUTHOR]- Published
- 2022
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47. Wide band gap thiophosphates ASrPS4 (A = Li, Na, K, Rb, Cs): cation size effect induced successive structural transformation.
- Author
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Huang, Yi, Huang, Junben, and Zhang, Yong
- Subjects
ALKALI metals ,BAND gaps ,THIOPHOSPHATES ,CATIONS ,BIREFRINGENCE - Abstract
Metal thiophosphates have aroused much research interest due to their structural chemistry and possible applications as infrared functional materials. In this study, five quaternary Sr-based alkali metal thiophosphates ASrPS
4 (A = Li, Na, K, Rb, Cs) were obtained. Their structural comparison shows that their symmetry undergoes transformation from tetragonal (I41 /acd) to monoclinic (P21 /c) to orthorhombic (Pnma) system, which is induced by the cation size effects and coordination features of different alkali metal cations. The experimental and theoretical results demonstrate that the band gaps of all title compounds are large, namely 3.6–3.9 eV (experimental results) and 3.78–4.12 eV (HSE06). Theoretical analyses indicate that the [PS4 ] group could be regarded as a good unit for designing wide band gap compounds, and the birefringence of NaSrPS4 is 0.08 at the fundemental 1064 nm wavelength, which shows that it may be a potential infrared birefringent material. [ABSTRACT FROM AUTHOR]- Published
- 2022
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48. Chiral 2D and quasi-2D hybrid organic inorganic perovskites: from fundamentals to applications.
- Author
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Moroni, Marco, Coccia, Clarissa, and Malavasi, Lorenzo
- Subjects
PEROVSKITE ,OPTOELECTRONICS ,SPINTRONICS ,CATIONS - Abstract
Chiral 2D and quasi-2D hybrid organic–inorganic perovskites (HOIPs) are emerging as promising materials for a variety of applications principally related to optoelectronics and spintronics, thanks to the combined benefits deriving from both the chiral cation and the perovskite structure. Since its recent birth, this research field is tremendously growing, focalizing on the chemical composition tuning to unveil its influence on the related functional properties as well as on developing devices for practical applications. In this review, we focused on the properties of 2D and quasi-2D chiral HOIPs, firstly providing an overview on their chiroptical behaviour followed by their potential exploitation in devices investigated so far for various applicative fields. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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49. A facile method for pre-insertion of cations and structural water in preparing durable zinc storage vanadate cathodes.
- Author
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Wang, Yujian, Wang, Shuying, Yang, Linyu, Zhao, Fengjun, and Li, Haibing
- Subjects
VANADIUM oxide ,ENERGY storage ,METAL ions ,SUPERCAPACITOR electrodes ,HIGH temperatures ,CATIONS ,CATHODES - Abstract
For improving the overall energy storage performance of aqueous zinc-ion battery (ZIB) systems, it is important to identify new cathode materials with superior characteristics. Along these lines, in this work, Na, K, and structural water were pre-inserted in vanadium oxide via a simple solution reaction method at room temperature. More specifically, Na
2 V6 O16 ·1.96H2 O (NVO) and K2 V6 O16 ·2.13H2 O (KVO) nanorods were successfully prepared using CH3 COONa and CH3 COOK, respectively, and commercial V2 O5 powder as starting materials. The NVO and KVO nanorods exhibited high Zn2+ storage ability; while the specific capacity of the NVO cathode reached 366.8 mAh g−1 at 0.3 A g−1 , its capacity retention was 86.6% after 1000 consecutive cycles at 3 A g−1 , and the KVO cathode also showed impressive performance. NaV3 O8 and KV3 O8 were prepared for comparison by annealing NVO and KVO at high temperatures. The comparison of their cycling stability, Zn2+ diffusivity coefficients, and electronic conductivity with the same characteristics of both NVO and KVO cathodes demonstrated that the presence of structural water had a positive impact on the electrochemical performance of the prepared materials. The high performance of NVO and KVO is mainly attributed to the synergistic effect between structural water and metal ions. [ABSTRACT FROM AUTHOR]- Published
- 2022
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50. Covalent triflates as synthons for silolyl- and germolyl cations.
- Author
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Wohltmann, Wiebke Marie, Schmidtmann, Marc, and Müller, Thomas
- Subjects
LEWIS acidity ,PERMUTATION groups ,CATIONS ,METATHESIS reactions ,CHEMICAL shift (Nuclear magnetic resonance) - Abstract
The synthesis of 1-silolyl and 1-germolyl triflates from the corresponding chlorides by salt metathesis reaction is reported. These covalent triflates are ideal starting materials for the preparation of ionic silolyl- and germolyl-imidazolium triflates by their reaction with N-heterocyclic carbenes. Similarily, ionic silolyl- and germolyl-oxophosphonium triflates are obtained by substitution of the triflate group by triethylphosphane oxide Et
3 PO. The analysis of their31 P NMR chemical shifts according to the Gutmann–Beckett method reveal the high Lewis acidity of the underlying silolyl and germolyl cations. Further analysis of structural and NMR parameters of the silolyl- and germolyl-imidazolium and oxophosphonium triflates indicates that these compounds are covalently bonded silole and germole derivatives with insignificant contributions from silolyl- or germolyl cations. Silolyl and germolyl triflates are however synthetic equivalents of these cations and might serve as a source for electrophilic silolyl and germolyl units. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
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