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Naphthalenediimide derivative-absorbed papers, which were prepared by dropping chloroform solution, showed fluorescence under photoirradiation after exposure to vapors of small aromatic guests. The fluorescence intensity and maximum wavelength depended on the type of guest aromatic molecules, similar to the crystal. The naphthalenediimide derivative-absorbed papers showed vapochromic and mechanochromic properties. [ABSTRACT FROM AUTHOR]

Integrating multi-stimuli response properties in one molecule is challenging. This study presents two 2D polymers, [(Bpydp)Ln(H2O)(BDC)]·NO3·2H2O (Ln = Eu(1), Tb(2)), exhibiting rapid photo-responsiveness and the ability to detect specific small-molecule amines. In particular, complex 1 combines the functions of inkless printing, amine detection, anti-counterfeiting, and fluorescence recognition. [ABSTRACT FROM AUTHOR]

In this paper, we present the synthesis of four new complexes: the dimeric precursor [Ir(dmppz)2(μ-Cl)]2 (1) (Hdmppz -- 3,5-dimethyl-1-phenyl-1H-pyrazole) and heteroleptic bis-cyclometalated complexes: [Ir(dmppz)2(Py2CO)]PF6•½CH2Cl2 (2), [Ir(dmppz)2(H2biim)]PF6•H2O (3), and [Ir(dmppz)2(PyBIm)]PF6 (4), with auxiliary N,N-donor ligands: 2-di(pyridyl)ketone (Py2CO), 2,2'-biimidazole (H2biim) and 2-(2'-pyridyl)benzimidazole (PyBIm). In the obtained complexes, SC-X-ray analysis revealed that Ir(III) has an octahedral coordination sphere with chromophores of the type {IrN2C2Cl2} (1) or {IrN4C2} (2-4). The complexes obtained, which have been fully characterised by physicochemical methods (CHN, TG, FTIR, UV-Vis, PL and ¹H, 13C, 15N NMR), were used to continue our studies on the factors influencing the cytotoxic properties of potential chemotherapeutic agents (in vitro). To this end, the following studies are presented: (i) comparative analysis of the effects on the biological properties of N,N-donor ligands and C,N-donor ligands in the studied complexes, (ii) studies of the interactions of the compounds with the selected molecular target: DNA and BSA (UV-Vis, CD and PL methods), (iii) and the reactivity towards redox molecules: GSH, NADH (UV-Vis and/or ESI-MS methods), (iv) cytotoxic activity (IC50) of potential chemotherapeutics against MCF-7, K-562 and CCRF-CEM cell lines. [ABSTRACT FROM AUTHOR]

Precise manipulation of individual DNA molecules entering and leaving the channel ports, as well as their smooth passage across the channel, is essential for the detection and screening of DNA molecules using nano-/micro-fluidic technologies. In this paper, by combining single-molecule fluorescence imaging and numerical simulations, the motion states of DNA molecules translocating through a microfluidic channel under the action of the applied electric field are monitored and analyzed in detail. It is found that, under certain conditions of the applied electric field DNA molecules exhibit various motion states, including translation crossing, deflection outflow, reverse outflow, reciprocal movement, and elliptical movement. Simulations indicate that, under the action of Saffman force, DNA molecules can only undergo deflective motion when they experience a velocity gradient in the microchannel flow field; and they can only undergo elliptical motion when their deflective motion is accompanied by a spin motion. In this case, the Magnus force also plays an important role. The detailed study and elucidation of the movement states, dynamic characteristics and mechanisms of DNA molecules such as the deflective and elliptical motions under the actions of Saffman and Magnus forces have helpful implications for the development of related DNA/gene nano-/microfluidic chips, and for the separation, screening and detection of DNA molecules. [ABSTRACT FROM AUTHOR]

We present in this paper the stability of SWCNT hybrid systems with Py molecules. vdW type interactions are therefore the main interaction mechanism between encapsulated molecules and nanotubes, and the simplest model to describe these interactions is the Lennard-Jones potential. We have therefore performed energy minimization calculations on hybrid SWCNTs in a very wide range of diameters and of all chirality using the Lennard-Jones potential. The structure of the carbon nanotube is obtained from the winding of graphene on itself to form a hollow cylinder described by the pair of integers (n, m) entirely determining its structural characteristics, while the optimization of the geometry of the Py molecule is obtained by SIESTA using the exchange–correlation functional LDA. After minimisation, an approach that combines density functional theory, molecular mechanics, bond polarizability model, and spectral moment's method has been used to compute Raman spectra. Two types of vibration modes of SWCNTs attract our attention. Initially, the modifications of the modes of Py after encapsulation will be analyzed. In the following discussion, we examine how the vibrational properties of single-walled carbon nanotubes (SWCNTs) are affected by encapsulation, specifically in relation to the RBM and tangential modes. Our analysis of the Raman active modes supports the notion that the structural integrity of the SWCNTs remains intact and indicates the occurrence of a charge transfer between the Py molecules and SWCNTs. This charge transfer depends on the geometric position of Py in the SWCNT. [ABSTRACT FROM AUTHOR]

Radical-cation salts of formula β?-(BEDT-TTF)4[(H3O)Fe(C2O4)3]·guest have produced a large number of superconductors and provided a route to introduce magnetism and chirality into the same multifunctional material. A relationship has been found in these salts between the length of the b axis and the superconducting Tc. Increasing the b axis length by introducing larger guest molecules, such as benzonitrile and nitrobenzene, gives the highest superconducting Tcs in this family of salts. Smaller guests such as pyridine show no superconducting transition, whilst asymmetrical guests which are larger than nitrobenzene have given a different bilayered structure. Other potential guest molecules have been limited by their ability to be used as the solvent in which the crystals are grown via electrocrystallisation. This paper reports a method which introduces guest molecules into the crystal which are a solid or liquid additive within the crystal-growing solvent 1,2,4-trichlorobenzene:ethanol. We present the crystal structures of five new BEDT-TTF radical-cation salts with tris(oxalato)ferrate anions using guest molecules toluene, phenol, benzaldehyde, 4-bromobenzaldehyde, and kojic acid. [ABSTRACT FROM AUTHOR]

Small molecules find extensive application in medicine, food safety, and environmental studies, particularly in biomedicine. Immunoassay technology, leveraging the specific recognition between antigens and antibodies, offers a superior alternative to traditional physical and chemical analysis methods. This approach allows for the rapid and accurate detection of small molecular compounds, owing to its high sensitivity, specificity, and swift analytical capabilities. However, small molecular compounds often struggle to effectively stimulate an immune response due to their low molecular weight, weak antigenicity, and limited antigenic epitopes. To overcome this, coupling small molecule compounds with macromolecular carriers to form complete antigens is typically required to induce specific antibodies in animals. Consequently, the preparation of small-molecule artificial antigens and the production of efficient specific antibodies are crucial for achieving precise immunoassays. This paper reviews recent advancements in small molecule antibody preparation technology, emphasizing the design and synthesis of haptens, the coupling of haptens with carriers, the purification and identification of artificial antigens, and the preparation of specific antibodies. Additionally, it evaluates the current technological shortcomings and limitations while projecting future trends in artificial antigen synthesis and antibody preparation technology. [ABSTRACT FROM AUTHOR]

Quinones are valuable structural motifs found in numerous natural products and pharmaceuticals. In particular, p-benzoquinones are of great interest because of their ready availability and versatile reactivity. They can serve as good Michael acceptors and participate in many cycloaddition, nucleophilic addition and multicomponent reactions. However, the construction of polycyclic architectures with increased stereochemical features is another perspective of quinone chemistry. The present review summarizes the recent advances (2018–2023) in stereoselective annulation involving p-benzoquinones for the construction of fused, spiro and bridged/cage frameworks. In this regard, different types of annulations, such as [3+2], [3+3], [3+2+1], [4+2] and [2+2], are discussed for accessing diverse fused heterocycles in a stereoselective manner. Some novel annulation methods are reviewed for building spiro heterocycles and cage molecules. Most of the reactions described in this review are simple, providing quick formation of the desired products with high stereoselectivity. In this regard, typical reaction mechanisms are presented to understand how quinoidal scaffolds show variable reactivity towards reaction partners. [ABSTRACT FROM AUTHOR]

In this paper, a series of coordination polymers, {[Zn(adb)(L1)2]·solvent}n (L1 = solvent = N,N-dimethylacetamide, Hui-3-DMA; L1 = N,N-dimethylformamide and no solvent, Hui-3-DMF; L1 = N,N-diethylformamide and no solvent, Hui-3-DEF) have been synthesized by hydrothermal reactions of Zn(NO3)3·6H2O and 4,4′-(anthracene-9,10-diyl)dibenzoic acid (H2adb). These compounds show similar one-dimensional (1D) zig-zag chain structures, which are limited by the end-coordination of the solvent molecules. Interestingly, these compounds all show blue-emission properties, which could be easily modulated by using different solvents. Among them, Hui-3-DMA presents an excellent quantum yield performance, as high as to 54.1%, which is very promising for blue-emission materials. Moreover, various-temperature fluorescence studies reveal good linear or exponential decline trends for their emission intensity as temperature increases, demonstrating the potential of these compounds as fluorescent thermometers. [ABSTRACT FROM AUTHOR]

Calcite is widely used in many fields. The synthesis of calcite is strongly influenced by solvents and additives. In this paper, the adsorption of water and formic acid molecules on the (104) surface of calcite was systematically studied on the atomic scale using the density functional theory (DFT) method. The results show that both molecules can be adsorbed on the calcite surface by occupying the top position of Ca. The results of differential charge density and the projected crystal orbital Hamiltonian population show that the adsorption is controlled by the charge transfer from the oxygen atom to the surface calcium. Formic acid has a carbonyl oxygen and it plays a greater role in stabilizing the surface than water. Moreover, the adsorption of two molecules can be further stabilized by hydrogen bonds formed between the hydrogen atom in the adsorbed molecules and the oxygen in calcite. This work provides a clear understanding of the stabilization of the calcite surface by adsorbing different molecules and also provides the possibility of tuning the synthesis of calcite by choosing a suitable solvent and additives. [ABSTRACT FROM AUTHOR]

In recent years, compounds from the Schiff base group have been intensively studied for their biological activities. Accordingly, a series of Schiff bases were synthesized from substituted aromatic aldehydes (5-chlorosalicylaldehyde) and differently substituted aromatic amines and their antimicrobial activities were evaluated. The molecular identity of compounds was confirmed using various spectroscopic techniques, such as IR and NMR spectroscopy and elemental analysis, and the molecular structure of compound 3k was determined by single-crystal X-ray analysis. The antimicrobial activity of 3a–3k compounds was examined in sixteen microorganisms (five species of bacteria and eleven species of fungi) using the microdilution method. Regarding antibacterial activity, a remarkable MIC value (0.0098 mg mL−1) and, therefore, the best activity was displayed against Proteus mirabilis for 3e, which is even stronger than the most frequently used antibiotic medications. 3f showed the best antifungal activity against Microsporum gypseum, which is stronger than standard antimycotic fluconazole, and is also an important result considering that Microsporum gypseum can cause dermatophytosis in both humans and animals. [ABSTRACT FROM AUTHOR]

A case of organic–inorganic hybridized phosphotungstate modified using aromatic organophosphonic acid, K4Na4H11[KCo2(H2O)10P4W24O92{(PhPO)2}]·48H2O (1), was successfully synthesized in conventional aqueous solution. The prominent structural feature is that the total structure of [KP4W24O92{(PhPO)2}]23− resembles a V-shaped structure, which was stabilized by two [Co(H2O)5]2+ ions. Furthermore, it can be connected into a three-dimensional mesh structure using K+ ions. Surprisingly, 1 possesses a remarkably high proton conductivity of 1.59 × 10−2 S cm−1 at 95% RH and 318 K probably due to the fact that its structure contains large amounts of lattice water molecules, coordination water molecules and counter cations. [ABSTRACT FROM AUTHOR]

The electronic and nonlinear optical (NLO) properties of Al13–X and 2Al13–X (where X represents dianhydrides BPDA, BTDA, ODPA, and 6FDA) were systematically investigated using (time-dependent) density functional theory methods. It was found that Al13 could effectively bind to dianhydride molecules via two strong Al–O bonds with high binding energies. Compared to pristine Al13 and dianhydrides, hybridized complexes Al13–X exhibit significant enhancements in both linear and nonlinear optical response properties, as evidenced by the calculated isotropic polarizability and static/dynamic first hyperpolarizabilities, respectively. The nature of the large first hyperpolarizabilities of Al13–X complexes can be understood by analyzing the low excitation energies of the key excited states and the first hyperpolarizability density. Furthermore, the dianhydride ligand is capable of bridging two aluminum clusters to form a novel D–A–D molecule, which further enhances the NLO properties of the molecules. It is hoped that the current research work will provide ideas for the rational design of such inorganic–organic hybrid complexes as novel functional electro-optical materials. [ABSTRACT FROM AUTHOR]

The core skeleton syntheses of 3′H-spiro[cyclohexane-1,1′-isobenzofuran]-2,5-dien-4-one, and their derivatives (3a–3w) of spirobisnaphthalene urnucratins, plecmillins, and lignan kadsulignan, were explored using Suzuki–Miyaura coupling product biphenols as the precursors and intramolecular oxidative dearomatization with high-valence iodine reagent PIFA as the key step in 46–91% yields. A wide range of functional groups were tolerated. Then, using this strategy in combination with the Diels–Alder reaction, two skeleton molecules (5ah and 6d) of the natural products urnucratins and plecmillins were successfully constructed in 78% and 39% overall yields, which provides a potential methodology for the total synthesis of Type D spirobisnaphthalene urnucratins and other natural products with similar structures. [ABSTRACT FROM AUTHOR]

In this study, we present a series of theoretically designed B2G14G14' molecules, featuring four-membered-ring heterocycles containing boron and heavy group 14 elements (G14 and G14' = Si, Ge, Sn, and Pb). Through the use of density functional theory (DFT), natural bond orbital (NBO) analysis, quantum theory of atoms in molecules (QTAIM), and electron localization function (ELF), our studies demonstrate a strong π single bond between the bridgehead G14 and G14' atoms, with minimal participation from a very weak G14-G14' σ bond. Additionally, the nucleus independent chemical shift (NICS), anisotropy of current-induced density (ACID), and adaptive natural density partitioning (AdNDP) analyses definitively establish the presence of both σ-aromaticity and π-aromaticity in these inorganic four-membered heterocyclic neutral molecules. [ABSTRACT FROM AUTHOR]

CrystEngCommrsc. li/ crystengcomm ISSN 1466- 8033 Volume 26 Number 32 28 August 2024 Pages 4251– 4396 PAPER Masatoshi Kawahata et al. Inclusion of halobenzene in water- mediated hydrogen- bonded architectures built from a V- shaped host molecule [Extracted from the article]

We developed water-mediated hydrogen-bonded architectures containing guest molecules in the solid state, where water molecules are incorporated into the hydrogen-bonded organic frameworks. The crystallization of V-shaped host disubstituted adamantane with dimethoxyphenol moieties in halobenzene gave four inclusion crystals with an approximately 1 : 1 : 1 host/halobenzene/water stoichiometric ratio. Single-crystal X-ray crystallography revealed that hydrogen-bonded layers of cyclic structures of host and water molecules were formed, and guest molecules were accommodated within the cavities. The use of trisubstituted adamantane with dimethoxyphenol moieties afforded no single crystals. On the other hand, the use of tetrasubstituted adamantane with dimethoxyphenol moieties gave inclusion crystals, but there were no water molecules in the hydrogen-bonded structures. V-shaped host disubstituted adamantane incorporated water molecules to form a cavity for guest inclusion. [ABSTRACT FROM AUTHOR]

The synthesis of three novel [C,N,N′] Pt(IV) cyclometallated compounds containing hydroxo, dichloroacetato or trifluoroacetato axial ligands is reported. Compound [PtCl(OH)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (3) was prepared by the oxidative addition of hydrogen peroxide to [C,N,N′] Pt(II) cyclometallated compound [PtCl{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (1) and further the reaction of compound 3 with dichloroacetate or trifluoroacetate anhydrides led to the formation of the corresponding compounds [PtCl(CHCl2COO)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (4) and [PtCl(CF3COO)2{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (5). The properties of the new compounds along with those of the compound [PtCl3{(CH3)2N(CH2)2N＝CH(4-FC6H3)}] (2), including stability in aqueous media, reduction potential using cyclic voltammetry, cytotoxic activity against the HCT116 CRC cell line, DNA interaction, topoisomerase I and cathepsin inhibition, and computational studies involving reduction of the Pt(IV) compounds and molecular docking studies, are presented. Interestingly, the antiproliferative activity of these compounds against the HCT116 CRC cell line, which is in all cases higher than that of cisplatin, follows the same trend as the reduction potentials so that the most easily reduced compound 2 is the most potent. In contrast, according to the electrophoretic mobility and molecular docking studies, the efficacy of these compounds in binding to DNA is not related to their cytotoxicity. The most active compound 2 does not modify the DNA electrophoretic mobility while the less potent compound 3 is the most efficient in binding to DNA. Although compounds 2 and 3 have only a slight effect on cell cycle distribution and apoptosis induction, generation of ROS to a higher extent for the most easily reduced compound 2 was observed. [ABSTRACT FROM AUTHOR]

The ability of analytical strategies to detect and positively identify molecules under extremely dilute conditions is important for the growth and expansion of analytical techniques and instrumentation. At present, few measurement science techniques can robustly approach the measurement of just a few thousand molecules. Here, we present an electrochemical platform for the detection and positive identification of fewer than 1000 molecules of decamethylferrocene ((Cp*)2FeII). We achieve this remarkable detection threshold by trapping (Cp*)2FeII in a 1,2-dichloroethane microdroplet, which is allowed to dissolve into an aqueous continuous phase while on a gold microelectrode (radius ∼6.25 μm). Because electrochemistry is not sensitive enough to observe the charge of less than 1000 molecules, we dissolved μM amounts hexacyanoferrate(III) in the aqueous continuous phase. The biphasic reaction between hexacyanoferrate(III) and Cp2*(Fe)II allows for a feedback loop when the microelectrode is biased sufficiently negative to reduce Cp2*(Fe)III. This feedback loop, a typical EC′ catalytic mechanism, amplifies the electrochemical signal of Cp2*(Fe)II when the droplet is of small enough dimensions for feedback to occur. Our results demonstrate that clever biphasic reactions can be coupled with dissolving microdroplets to access extremely low limits of quantitation in electroanalysis. [ABSTRACT FROM AUTHOR]

Crystallisation of anthraquinone substituted p-tert-butylthiacalix[4]arene in the partial cone conformation from a range of solvents led to the isolation of two solvates, containing a mixture of chloroform and acetonitrile (PC1a) or toluene (PC1d) molecules, the structures of which were uncovered by SCXRD studies. Upon heating, the former solvate undergoes a single-crystal-to-single-crystal transformation, leading to removal of the acetonitrile molecules from the host and repositioning of the chloroform molecules (PC1b). This is connected with rearrangements of the non-covalent interactions, nicely reflected by a change in the hydrogen bond acceptor of the weak C–H⋯O hydrogen bonds. The transformation process is reversible, as confirmed by exposure of the crystal to acetonitrile vapour. Furthermore, the guest free phase of PC1 was obtained by melt crystallisation (PC1c). [ABSTRACT FROM AUTHOR]

In the present work, we have studied the effect of the axial ligands, solvation, and oxidation and reduction on the structure and the nature of the Fe–Fe bonding of [Fe3L3] complex. The NCS−, CN−, and NO3− ions have been placed at the axial position of the [Fe3L3], giving [Fe3L3X2], where X represents NCS−, CN−, and NO3− ions. Our DFT results show that the structure of the [Fe3L3] molecule remains symmetrical regardless of the nature of the capped ligand. The ΔFe–Fe value is 0.01 Å, which falls within the range of symmetrical values (ΔM–M within 0.05 Å) of all the three complexes: [Fe3L3CN2], [Fe3L3(NCS)2], and [Fe3L3(NO3)2]. Next, we examined the solvation effect using benzene and toluene. Our results demonstrate no effect of solvation on the structure of [Fe3L3CN2] and [Fe3L3(NCS)2], as the ΔFe–Fe values remain consistent with the gas-phase structure and also X-ray value. Finally, in terms of the redox effect, our calculations indicate that the first oxidation process removes an electron from the σ* orbital, resulting in [Fe3L3]1+. This oxidation leads to unsymmetrical metal–metal bonds, with Fe1–Fe3 and Fe1–Fe2 measuring 2.35 Å and 2.52 Å, respectively. The second oxidation process removes another electron, this time from the δ* (HOMO-1) orbital, yielding [Fe3L3]2+. This electron removal also results in an unsymmetrical structure, with Fe1–Fe3 of 2.35 Å and Fe1-Fe2 of 2.53 Å, similar to that of the [Fe3L3]1+. This similarity is due to the removal of an electron from the weakly overlapped anti-bonding δ* orbital. The reduction process has a less pronounced effect on the structure of [Fe3L3] compared to that of the two-oxidation process. The Fe–Fe bond lengths of [Fe3L3]1− are the same as those of the natural molecule, with Fe1–Fe3 of 2.39 Å and Fe1–Fe2 of 2.42 Å. [ABSTRACT FROM AUTHOR]

In this paper, based on the reported OTTAB, OTTTB and eight newly designed compounds, the DFT/TD-DFT theory is utilized to study the influence of the electron-accepting ability of the central core, the electron-accepting ability of the substituent and the substituent position on the frontier molecular orbital, electronic absorption, hole reorganization energy and second-order nonlinear optical (NLO) properties. This investigation reveals that replacing the left OT unit in OTTTB with an IC unit with an ethylene double bond is the most effective way to increase the maximum absorption peak, reduce the hole reorganization energy and enhance the second-order NLO properties. Considering that the studied compounds have a smaller hole reorganization energy and larger static first hyperpolarizability, they may become highly potential hole transport materials and strong second-order nonlinear materials. [ABSTRACT FROM AUTHOR]

Transforming current complementary metal–oxide–semiconductor (CMOS) technology to fabricate memory chips and microprocessors into environmentally friendlier electronics requires the development of new approaches to resource- and energy-efficient electron transport and switching materials. Metal and multi-metal oxide layers play a key role in high-end technical applications. However, these layers are commonly produced through high-energy and high-temperature procedures. Herein, we demonstrate our first attempts to obtain stimuli-responsive mixed-metal oxide thin films from solution-processed molecular precursors under milder conditions. The molecular compounds of interest were prepared by one-pot reactions of a CoII carboxylate complex, triethylamine (Et3N), N-butyldiethanolamine (H2bda), and a hexanuclear complex [Ce6O4(OH)4(piv)12] (Hpiv = pivalic acid) or [Zr6O4(OH)4(ib)12(H2O)]·3Hib (Hib = isobutyric acid) in acetonitrile solution. The resulting charge-neutral, heterometallic coordination compounds display a ligand-supported pentanuclear {Ce IV3 Co III2 } core (in 1) and a dodecanuclear {Zr IV6 Co II6 } core (in 2), exhibiting thermal stability up to ca. 100 °C in air. Compound 2 was deposited and analyzed on Au(111) and SiO2/Si(100) surfaces to explore its potential as a single-molecule precursor for the preparation of atomically precise, complex mixed-metal oxide thin films. The adsorption characteristics of it demonstrate the ability to form stable agglomerates on the investigated surfaces. [ABSTRACT FROM AUTHOR]

The current work demonstrates the reversible control of substantial molecular motion in 'nano-sized' molecules, where two structural isomers can 'open' and 'close' their cavities in response to light or heat. The isomers differ widely in their photophysical properties, including colour, polarity, two-photon absorption and π-conjugation, and can easily be separated through column chromatography and thus have wide applicability. [ABSTRACT FROM AUTHOR]

As a gasotransmitter, carbon monoxide can induce tumor cell apoptosis by reversing the Warburg effect. Carbon monoxide-releasing molecules (CORMs) are a promising option for CO administration, but how to deliver the threshold concentration of CO into the tumor tissue remains a challenge. A series of novel targeted CORMs combining glycyrrhetinic acid (GA) derivative conjugates with a lipophilic mitochondriotropic triphenylphosphonium cation (TPP+) moiety were synthesized and evaluated for their antitumor activities. Among the complexes, complex 2 possessed excellent antitumor activities in HepG2 cells with IC50 values of 12.18 ± 4.66 μM compared with 5-FU. It caused the production of reactive oxygen species and reduced the mitochondrial membrane potential against HepG2 cells. Western blot analysis showed that complex 2 up-regulated the expression of the Bax protein and down-regulated the expression of Bcl-2, activated caspase-3, and HO-1. The docking study demonstrated that complex 2 can interact with the Bcl-2 protein through hydrophobic interaction and hydrogen bonds. The aforementioned results indicated that complex 2 triggered cell apoptosis through a mitochondrial pathway. These results suggest that the complexes may be promising anticancer agent candidates. [ABSTRACT FROM AUTHOR]

The use of HZSM-5 and modified catalysts for the pyrolysis of lignin to produce aromatics has been extensively investigated. But certain limitations including catalyst deactivation and high-cost modifications still exist. A magnetic field (MF) was used to assist Fe and HZSM-5 catalytic lignin pyrolysis for aromatics production in this study. Product composition analysis revealed that the monocyclic aromatic hydrocarbon (MAH) and benzene, toluene, ethylbenzene, and xylene (BTEX) contents exhibited an upward trend in correlation with the MF intensity. The introduction of a MF significantly affects the improvement of the BTEX yield. Under the conditions of 80 mT MF intensity, 500 °C temperature and 50 mL min−1 carrier gas flow rate, the MAH and BTEX contents reach 32.94% and 27.19%, while the BTEX yield reaches roughly 19.55 mg g−1. Compared to no MF, these values rose by about 1.28, 1.36, and 1.94 times, respectively. Characterization results from XRD, XPS, TPO, N2 adsorption–desorption, and NH3–TPD tests showed that the MF facilitated the deoxidation and fragmentation of macromolecular oxygenates on the surface of Fe, promoting the ingress of smaller molecular compounds into the pores of HZSM-5 and boosting MAH production. Simultaneously, the MF impeded pore blockage in HZSM-5 and kept acidic sites from deactivating due to carbon deposition. This study lays a crucial groundwork for improving advanced technologies aimed at optimizing the utilization of organic solid waste. [ABSTRACT FROM AUTHOR]

The prevalence of the D–A strategy in achieving red-shifted emission has been established through designing D–A molecules of D–A–D and A–D–A constructs. Architectural control over such D–A systems integrates solid state NIR emission with lysosome tracking and sets a multifarious goal of photophysical modulation in a comprehensive way. In particular, two compounds, CPM–1 (D–A–D) and CPM–2 (A–D–A), have been synthesized by introducing carbazole-based donors and difluoroboron acceptors. Lysosome targeting and imaging have been achieved through incorporation of a morpholine unit, which ultimately imparts viscosity sensitivity to the construct. The fluorophores exhibited significant emission in solution along with distinctive solvatochromism, viscochromism and TICT. A comparative account of these competitive photophysical properties revealed the superior charge transfer properties of the A–D–A construct (CPM–2), while the D–A–D molecule (CPM–1) was found to be a better molecular rotor with marked viscochromism. The solid state NIR emission has been found to be much more intense in CPM–1 relative to CPM–2, which further highlights the influence of structural aspects on photophysical behvaiour. Theoretical studies further established the distinctive characteristics of ground and excited states in these compounds. Owing to its excellent viscochromic behvaiour, CPM–1 has been successfully utilized in lysosome targeting in wild-type Drosophila fly gut tissues through co-localization studies. [ABSTRACT FROM AUTHOR]

A water-mediated and Rh-catalysed one-pot multi-step synthesis of chiral 1,3-diarylpropan-1-ols is presented. This protocol utilizes readily available terminal alkynes and aldehydes as reaction partners, and features mild conditions, easy operation and water as the sole solvent, thus serving as an ideal means for the efficient synthesis of chiral 1,3-diarylpropan-1-ols. Control experiments suggested that the formation of chalcone intermediate followed by a double reductive process is crucial for the success of the reaction. This catalytic methodology could be easily scaled up for gram-scale synthesis with up to 10 000 S/C and the resulting products can be used to easily derive various bioactive molecules. [ABSTRACT FROM AUTHOR]

A novel approach has been developed for the efficient synthesis of the unsymmetrical (2-aminopyrrolidin-1-yl)carboxamidine alkaloidal core found in cernumidine (1) and its analogs (20a, 20c, 20f, 20i–o). The key transformation in this process involves the utilization of the Curtius rearrangement, which plays a pivotal role in constructing the aminal moiety. One of the major challenges encountered during this synthesis was the instability of the free aminal core intermediate. Furthermore, a noteworthy observation during the synthesis was the racemization process that occurred during the isocyanate trapping by organometallic reagents. Detailed DFT calculations shed light on this phenomenon, revealing a neighboring coordination-induced mechanism. The resulting compounds were subjected to evaluation for their anti-inflammatory properties using lipopolysaccharide-stimulated human THP1 cells. Notably, compounds featuring the guanidine moiety and electron-donating groups exhibited significant anti-inflammatory activity. These findings suggest that these compounds hold promise as potential candidates for further development as anti-inflammatory agents. [ABSTRACT FROM AUTHOR]

For a series of chiral para-alkylphenyl glycerol ethers—para-Alk–C6H4–OCH2CH(OH)CH2(OH) [Alk = Me (1), Et (2), n-Pr (3), n-Bu (4), iso-Pr (5), tert-Bu (6)]—we used information on their solubility in cyclohexane and thermochemical melting parameters to calculate the standard free energies of dissolution, , and melting, ΔG 0f. Our observations showed consistent patterns in these parameters within the homologous series. This analysis allowed us to compare the energy characteristics of the crystal structures, thus enabling the quantification of enantiophobic and enantiophilic effects. Furthermore, it facilitated the examination of trends in chiral discrimination as the molecular constitution changed sequentially. We identified distinct trends for enantiopure substances and corresponding racemic compounds within the series studied. In particular, the difference in crystal packing energies among the series members following these trends favours racemic molecular compounds by approximately 2.5 kJ mol−1. However, for (R)-3 and (R)-4, the realised crystal structures are more energetically favoured than expected, thus deviating from the established correlations. This anomaly allows homochiral crystal structure 3 to bridge the energy gap and crystallise from the racemic mixture as a thermodynamically more favourable conglomerate of enantiomeric crystals. In contrast, for racemic compound rac-5, the energy of its molecular packing is lower than expected from the correlations but insufficient to make conglomerate 5 thermodynamically more favourable. At the same time, the formation of racemic compound rac-6 was abnormally preferable in terms of energy. In addition, we presented the X-ray diffraction data for the homo- and heterochiral crystals of 5, thereby complementing the structural information available for the "chiral pool" class of glycerol derivatives. [ABSTRACT FROM AUTHOR]

To achieve highly sensitive detection using surface-enhanced Raman spectroscopy (SERS), it is imperative to fabricate a substrate with a high density of hot spots and facilitate the entry of target molecules into these hot spot regions. However, steric hindrance arising from the presence of surfactants and ligands on the SERS substrate may impede the access of target molecules to the hot spots. Here, we fabricate non-close-packed three-dimensional (3D) supraparticles with high-density hot spots to actively capture molecules. The formation of 3D supraparticles is attributed to the minimization of free energy during the gradual contraction of the droplet. The numerous capillaries present in non-close-packed supraparticles induce the movement of target molecules into the hot spot region through capillary force along with the solution. The results demonstrate that the SERS enhancement effect of 3D supraparticles is at least one order of magnitude higher than that of multi-layered nanoparticle structures formed under natural drying conditions. In addition, the SERS performance of 3D supraparticles is evaluated with diverse target molecules, including antimicrobial agents and drugs. Hence, this work provides a new idea for the preparation of non-close-packed substrates for SERS sensitive detection. [ABSTRACT FROM AUTHOR]

A novel benzimidazole-1,2,3-triazole hybrid molecule, 4-(1H-benzo[d]imidazol-2-yl)-1-(2-methoxyphenyl)-1H-1,2,3-triazol-5-amine, was synthesized. Two concomitant polymorphs of the title compound were crystallized from the same solution simultaneously. Various quantum chemical methods were used to explain the formation of these polymorphic structures and predict their stability to external influence. Studying the possibility of changing the conformation by rotating aromatic rings around single bonds using the m06-2x/cc-pVTZ method and analyzing the molecular structure of the compound in the obtained crystal forms showed that the studied polymorphs differ in the conformation of the molecules. Both polymorphic structures have close lattice energies calculated in a plane wave approximation and energetic structures constructed using pairwise interaction energies. Two polymorphic forms can be classified as a columnar-layered packing of the dimeric building units. Quantum chemical modeling of the displacement of layers relative to each other allows us to state that both concomitant polymorphs are resistant to external mechanical influence. Thus, it can be assumed that the studied concomitant polymorphs were formed not due to kinetic and thermodynamic factors affecting the crystallization process, but due to the ability of two conformers with close energies to form crystals very similar in structure. [ABSTRACT FROM AUTHOR]

Solution-Cathode Glow Discharge Optical Emission Spectrometry (SCGD-OES) is a cost-effective analytical technique due to its miniaturization potential and reduced consumption, useful for on-line and in situ aqueous solution elemental analysis, and to its adequate limits of detection, which are, on average, comparable with those of ICP-OES. The elemental response in SCGD-OES is frequently enhanced making use of low molecular weight compound additives, such as formic acid (HCOOH); however, this enhancement was shown to be affected by the presence of significant amounts of Na+ and Cl− ions, which are extensively present in a wide variety of samples. In this context, this work delves into the impact of HCOOH on analyte emission signals when analyzing solutions containing high concentrations of other cations (Na+, K+, Mg2+, and Ca2+) and anions (SO42−, Cl−, NO3−, HCO3− and Br−), which make up an ample variety of sample matrices, on SCGD-OES. In particular, the atomic emission intensity of certain analytes is observed to decline with increasing HCOOH additive concentration under certain sample matrix conditions. This intensity depression mainly appears when the sample matrix contains alkali cations, regardless of the anion type. Interestingly, elements with notable chemical vapor generation (CVG) efficiencies, such as Hg, Ag, Pb and In, maintain the positive HCOOH enhancement of emission intensity. HCOOH addition enhancement is also evaluated in a more complex sample, artificial seawater, showing similar results compared to those obtained with high NaCl concentration solutions due to the high proportion of these ions in seawater. Finally, the analytical performance of SCGD-OES is evaluated in terms of sensitivity and limits of detection, resulting that the addition of HCOOH for seawater analysis pays off when CVG-prone elements are targeted. [ABSTRACT FROM AUTHOR]

Extending the catalytic valorization roadmap of platform molecules is one of the core tasks in the development of the biomass conversion field. Through ongoing research efforts, the transformation system of biomass-derived platform molecules has been well established and is gradually becoming relatively mature. In this context, it is of great practical interest to further explore next-generation platform molecules and their valorization pathways that have recently emerged. Linear diketones, usually derived from biomass and their C6 furan compounds, are one of the novel platform molecules that have been recently spotlighted for the synthesis of high-end chemicals due to their huge valorization potential. Herein, we intend to underline the crucial platform role that linear diketones, i.e., 2,5-hexanedione (HD) and 1-hydroxy-2,5-hexanedione (HHD), play in extending the biomass valorization roadmap to a broader one. Perspectives are concentrated on elucidating the heterogeneous tandem conversion system of biomass and its derived C6 furan compounds to HD and HHD. Also, we further demonstrate the diverse valorization routes of HD and HHD to high-end chemicals for various applications. The insights presented in this paper may contribute to highlighting the bright future of linear diketones in constructing a sustainable biomass valorization system. [ABSTRACT FROM AUTHOR]

Multilayer automotive paint samples can be important evidence in forensic investigations but due to their inherent complexity it is a challenging task to analyze them. We herein present a method for a comprehensive chemical sample characterization based on the subsequent measurements of paint samples with Raman spectroscopy and laser induced breakdown spectroscopy (LIBS) at the same sampling points along the cross-sections of the paints. The method requires minimal sample preparation because the layers do not have to be separated. In combination with multivariate data analysis (namely k-means) the proposed method provides information both on the distribution of molecular compounds as well as elements which could then be used for the discrimination of different paints. Eight different samples were investigated and individual chemical profiles were found whereby a spatial resolution of close to 10 μm could be demonstrated. Investigation of different samples of the same origin showed similar profiles revealing the reproducibility of the proposed method. We therefore believe that our approach could be a good addition to the methods used so far for the analysis of paint samples. [ABSTRACT FROM AUTHOR]

Co-crystallization of cyclic nitramines with sterically crowded molecules, i.e., ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-CL-20) with cis-1,3,4,6-tetranitrooctahydroimidazo-[4,5-d]imidazole (BCHMX), is very difficult, but the co-agglomeration (slurry method) of their mixed micro-co-particles gives very good results. CL-20 is present in these co-agglomerates (CACs) in its β-form. Besides the medium of co-agglomeration, also the molar ratio is very important; it is possible to obtain β-CL-20/BCHMX (molar 1.8/1.0) with the impact sensitivity of 14.9 J. The density of these CACs approaches 99.6% of the density of the β-CL-20 crystals. Based on the application of the Raman, FTIR and PXRD techniques, it has been proved that the agglomeration of CL-20/BCHMX micro-co-particles leads to the formation of CACs mostly with the properties of co-crystals (CCs). This also seems to be confirmed by the relationships between the heat of formation and ring-deformation vibrations (in plane) and between the impact sensitivity and the difference in the asymmetric NO2 stretching vibrations in pure CL-20 and its CACs. The CACs studied have lower detonation energies than would be consistent with the percentage of individual coformers in these crystals. An examination of the most sensitive CACs (1.2 J) as a detonator primer has shown the absence of its required acceleration capabilities in the given detonator design. A comparison with literature data and our unpublished preliminary results indicates that the CACs and CCs of this type could have potential beneficial applications in propellants. [ABSTRACT FROM AUTHOR]

A dodecanuclear [Ni8Ca4] compound, [Ni8(L)8Ca4(CO3)4(dmf)5.5(H2O)6.5]·20H2O (1) (dmf = dimethylformamide) has been prepared by the reaction of a polydentate ligand (E)-2-(2-hydroxy-3-methoxybenzylidene)amino-4-nitrophenol (H2L) with NiCl2·6H2O, CaCl2·2H2O and Na2CO3 in dmf at room temperature. The solid-state molecular structure of compound 1 was determined by single crystal X-ray crystallography. Compound 1 consists of a [Ni8Ca4] coordination wheel with eight NiII ions and four CaII ions assembled by four carbonates and eight deprotonated L2− ligands. The asymmetric unit of compound 1 contains two NiII ions, one CaII ion, two coordinated deprotonated Schiff base ligands (L2−), one coordinated carbonate ion, two coordinated dmf molecules (one with occupancy of 0.36), two coordinated water molecules (one with occupancy 0.64). Compound 1 is the largest coordination cluster containing NiII and CaII ions reported to date. The magnetic properties of 1 show the presence of predominant antiferromagnetic interactions. The magnetic susceptibility and isothermal magnetization data can be well reproduced with: g = 2.145(1), J1 = 2.93(4) cm−1, J2 = −0.41(2) cm−1 and J3 = −5.66(4) cm−1. [ABSTRACT FROM AUTHOR]

The crystal structures and crystallisation behaviours of MII–TbIII–MII heterotrinuclear complexes, [(L)MTbM(L)]NO3 (M = Mn and Zn; L3− stands for a conjugated base of H3L = 1,1,1-tris[(3-methoxysalicylideneamino)methyl]ethane), obtained from various organic solvents (MeOH, EtOH, CH2Cl2 and CHCl3) were investigated. The trinuclear complex cation has two asymmetric centres (Δ or Λ) at two MII sites as a result of the twisted tripodal arms of L3−. Single-crystal X-ray diffraction analysis revealed that all the analysed Zn–Tb–Zn complexes had homochiral structures (Δ,Δ- or Λ,Λ-enantiomers) in each single crystal; however, the type of crystallisation behaviour showed clear differences depending on the type of solvent molecule. Specifically, crystallisation from MeOH or CH2Cl2 resulted in the exclusive formation of the Λ-conglomerates with the Λ,Λ-enantiomers—a phenomenon we recently termed 'absolute spontaneous resolution'. The analogous Mn–Tb–Mn complex crystallised from MeOH also resulted in the same phenomenon as that of Zn–Tb–Zn. In contrast, the meso-type (Δ,Λ) achiral isomer of the Mn–Tb–Mn complex was deposited for the first time in a series of MII–LnIII–MII trinuclear complexes from a CH2Cl2 or EtOH solution. Density functional theory calculations were performed to compare the thermodynamic stability of homochiral (Λ,Λ) and meso-type (Δ,Λ) complex cations of [(L)MnTbMn(L)]+ in MeOH and EtOH. Results were consistent with the molecular structures observed in the crystallographic analysis of the compounds deposited from these solvents. [ABSTRACT FROM AUTHOR]

Polycyclic aromatic hydrocarbons (PAHs) are well-known hazardous pollutants. As a result, numerous methods have been designed and developed for their effective treatment. In this study, an adsorption-oxidation degradation process was explored for PAH degradation using CuZnFeAl layered double hydroxide (LDH), which was synthesized using a co-precipitation method. LDH was then subjected to high-temperature roasting to obtain CuZnFeAl layered double oxide (LDO), which was subsequently modified with a sodium dodecyl sulfate solution (SDS) to obtain SDS/LDO. Characterization studies substantiated that SDS/LDO was successfully modified. Naphthalene (Nap) and phenanthrene (PA) were used as PAH model pollutants and the degradation effects of different oxidants were evaluated. The results of adsorption-oxidation coupling degradation showed that the conversion rates of Nap and PA using ozone as an oxidant over SDS/LDO reached 98.5% and 99.9%, respectively. The kinetic study of the degradation of Nap and PA by adsorption-oxidation showed that the degradation of Nap and PA followed pseudo-first-order reaction kinetics. A mechanism study verified the existence of several free radicals, such as ˙OH, 1O2 and ˙O2−, which can continuously degrade PAHs. The degradation of Nap and PA gradually resulted in small organic molecular compounds, such as phenolic compounds, esters and alcohols, and were finally oxidized into H2O and CO2. [ABSTRACT FROM AUTHOR]

Crystallographic investigations of eight homoleptic N,N′-dimethylpropyleneurea (dmpu) coordinated metal ions in the solid state, [Mg(dmpu)5]I2 (1), [Ca(dmpu)6]I2 (2), [Ca(dmpu)6](ClO4)2 (3), [Ca(dmpu)6](CF3SO3)2 (4), [Sr(dmpu)6](CF3SO3)2 (5), [Ba(dmpu)6](CF3SO3)2 (6), [Sc(dmpu)6]I3 (7), and [Pr(dmpu)6]I(I3)2 (8), and the complex [CoBr2(dmpu)2] (9) as well as the structures of the dmpu coordinated calcium, strontium, barium, scandium(III) and cobalt(II) ions and the cobalt(II) bromide complex in dmpu solution as determined by EXAFS are reported. The methyl groups in the dmpu molecule are close to the oxygen donor atom, causing steric restrictions, and making dmpu space-demanding at coordination to metal ions. The large volume required by the dmpu ligand at coordination contributes to crowdedness around the metal ion with often lower coordination numbers than for oxygen donor ligands without such steric restrictions. The crowdedness is seen in M⋯H distances equal to or close to the sum of the van der Waals radii. To counteract the space-demand at coordination, the dmpu molecule has an unusual ability to increase the M–O–C bond angle to facilitate as large coordination numbers as possible. M–O–C bond angles in the range of 125–170° are reported depending on the crowdedness caused by the coordination figure and the M–O bond distance. All reported structures of dmpu coordinated metal ions in both the solid state and dmpu solution are summarized to study the relationship between the M–O–C bond angle and the crowdedness around the metal ion. However, highly symmetric complexes seem to be favoured in the solid state due to favourable lattice energies. As a result, the dmpu coordinated lanthanoid(III) ions are octahedral in the solid state, while they, except lutetium, are seven-coordinate in the dmpu solution. [ABSTRACT FROM AUTHOR]

Exploring feasible tactics to induce the formation of non-centrosymmetric (NCS) structures, especially from centrosymmetric (CS) structures, is essential for the development of nonlinear optical crystals with more potential. An NCS alkali metal-containing molybdenum iodate hydrate, namely, NaMoO3(IO3)(H2O), was designed based on the CS matrix NaMoO3(IO3) via introducing a water molecule into the structure. The introduction of one crystalline water molecule results in the rearrangement of Λ-shaped cis-[MoO4(IO3)2] units, and the proper array of the cis-[MoO4(IO3)2] units in NaMoO3(IO3)(H2O) results in its strong SHG response of 4.6 × KH2PO4. In addition, NaMoO3(IO3)(H2O) exhibits a wider optical bandgap of 3.44 eV and a larger birefringence of 0.231 than its matrix. Furthermore, the framework of NaMoO3(IO3)(H2O) is highly similar to that of α-KMoO3(IO3), with water molecules assisting Na+ cations in occupying the position of K+. However, due to the extra hydrogen bond of water molecules, the [MoO3(IO3)]∞ layers in NaMoO3(IO3)(H2O) retain a parallel-stacking arrangement, different from the antiparallel arrangement of layers in α-KMoO3(IO3) with a centric structure. This study confirms the feasibility of applying a water molecule to adjust the orientation of basic building block units to assemble an NCS structure based on CS crystals. [ABSTRACT FROM AUTHOR]

The merging of fundamentally and biologically important heterocyclic structures, such as pyrroles, indoles, and imidazoles, in molecules of dihydropyrrolo[1′,2′:3,4]imidazo[1,2-a]indoles functionalized by E-acylethenyl groups was achieved in water on the platform of commercial 3H-indoles using readily available acylpyrrolylacetylenes as additional building blocks. The yields of the ensembles reached 88% (100 °C, 8 h), which is noticeably better than that produced using conventional solvents (MeCN, MeNO2, DMSO, and CF3CH2OH), wherein the reaction proceeds at a rate of approximately 10 times longer (96 h) with lower yields of the target products (not higher than 80%). The reaction presumably proceeds in a micellar-like microreactor self-assembled in a two-phase aqueous medium that secures favorable mutual orientation of the merging molecules, providing a facile [2+3] concerted cycloaddition to finally form fused polyheterocyclic systems. The performed DFT calculations are in agreement with such mechanistic considerations, particularly those underlying the crucial role of water in the studied cascade process. [ABSTRACT FROM AUTHOR]

In recent years, incredible endeavors have been devoted to the design and self-assembly of discrete covalent organic cages with expanding intricacy and functionality. They have excellent applications in different fields, but their applications in enantioselective separation have not been fully developed. Here, a pair of chiral cages with custom cavities based on the unique rigid structure of 1,10-binaphthol (binol) were selected for effective enantioseparation. Meanwhile chiral resolution tests reveal diverse host–guest stereoselectivity towards different chiral molecules. [ABSTRACT FROM AUTHOR]

Intermolecular interactions of drug molecules can lead to aggregation, which has a significant impact on their application. This problem might escape the attention when studying their solubility as small aggregates might behave almost as single molecules. We studied the aggregation behaviour of doxorubicin (DOX) molecules through density functional (DFT) methods and molecular dynamics (MD) simulations in water, dimethylformamide (DMF), ethanol (EtOH), and dimethyl sulfoxide (DMSO). We described the degree of aggregation by MD-calculated radial distribution function, combined radial/angular distribution functions, autocorrelation functions, and the number of hydrogen bonds of individual DOX and solvent atoms. MD-calculated diffusion coefficients for DOX decrease along the series water > DMF > EtOH > DMSO (0.101 × 10−9, 0.047 × 10−9, 0.025 × 10−9, and 0.007 × 10−9 m2 s−1, respectively) consistent with increasing aggregation found in the MD simulations. These aggregates have different characters, depending on the DOX⋯solvent interactions, and include hydrogen bonding and π-stacking. Even though the solvation energy of a single DOX molecule in DMSO (−24.8 kcal mol−1) is higher than in other solvents, the formation of larger aggregates in this solvent prevents proper solvation. Further, the orientation of doxorubicin molecules at octanol/water and dipalmitoylphosphatidylcholine (DPPC)/water interfaces was studied with two different orientations from the bivariate maps. In the case of the DPPC/water interface, the anthracycline part points toward the aqueous phase, while this part is oriented almost parallel to the octanol/water interface in DMSO. [ABSTRACT FROM AUTHOR]

Non-heme mononuclear iron complexes, especially when supported by tripodal tetradentate ligands, show promising C–H bond activation efficiency in catalytic reactions. Nevertheless, they intrinsically decay readily to their dinuclear form, and the dimerization process is inevitable in homogenous solution, which dramatically hinders their further application. Hence, we demonstrate that the mononuclear iron complex [(TPA)FeII-2L]2+ (L = labile ligands, mainly solvent molecules) was successfully encapsulated in a highly robust metal–organic framework UiO-66 via a two-step "ship-in-a-bottle" strategy. The nearly perfect size matching of the octahedral cages of the host UiO-66 provides ideal space confinement for the guest complex to protect from dimerization and dramatically increases the mono-nuclear complex stability compared to its un-confined state. The successful encapsulation of [(TPA)FeII-2L]2+ in UiO-66 was verified thoroughly by spectroscopy, microscopy, N2 adsorption, and electrochemistry characterization techniques. This work shows that encapsulating an unstable molecular complex in MOFs via a two-step "ship-in-a-bottle" strategy highlights opportunities for extending the heterogenization of homogeneous complexes. [ABSTRACT FROM AUTHOR]

Recycling minor actinides (Am, Cm and Np) from spent nuclear fuel is considered by a few countries as an important option for a future sustainable nuclear fuel cycle. For this purpose, solvent extraction processes are developed to separate minor actinides, especially from lanthanides and other fission products. The development of fast and powerful analytical methods is essential to acquire the data needed to model these processes and to improve their performances. For this purpose, this study presents the development, validation and application of a new analytical approach based on the simultaneous coupling of hydrophilic interaction chromatography (HILIC) to electrospray ionization mass spectrometry (ESIMS) and inductively coupled plasma mass spectrometry (ICPMS), using specific isotope dilution (SID) as a method of quantification for the determination of the affinity and selectivity of chelating molecules (TPAEN, NM and DTPA) towards lanthanides (Ln). The best separation conditions of natNd and natSm complexes formed with the three molecules were defined. Then, downscaling the separation was investigated, to reduce effluent volumes, the consumption of materials and the time devoted to experiments which are of concern in the nuclear field. The separation was carried out using an amide grafted stationary phase column in isocratic and gradient elution modes depending on the separation format. The separated complexes were online identified and the quantitative distribution of the Ln among the complexes was simultaneously determined owing to our quantification strategy. The results obtained were similar for the three separation formats, allowing us to validate the robustness of the method. By applying this method, the affinity of TPAEN, NM and DTPA present in competition for the complexation reaction with natNd and natSm was further determined in a single step, allowing a quick screening. Both selectivity and affinity of these molecules could be compared to select the most promising candidates. This approach can be advantageously extended to the evaluation of the affinity of various classes of chelating molecules used in very low quantities, towards elements of interest in the fields of energy, toxicology and the environment. [ABSTRACT FROM AUTHOR]

Recently, the protection strategy has received significant attention due to improved product selectivity and process efficiency for biomass conversion. In this work, an effective route to protect the carbonyl group of biomass-based furans with 1,3-propylene glycol followed by a simple but effective purification process is first established. Sulfamic acid, a commercially available, low-cost heterogeneous Brønsted acid catalyst, under different reaction conditions, exhibited excellent acetalization performance at gram level with good recyclability. Then, an efficient column chromatography-free purification protocol was established to give gram-level, high-purity acetal products by bypassing large eluent use, long processing times, and poor separation of strong polarity molecules by column chromatography. We further examined the protection group effect on selectivity during the hydrodeoxygenation, deoxygenation, or ring hydrogenation of biomass-derived furanic compounds over supports with different acidity/basicity under a reducing atmosphere that differs from previous reports that were typically focused on aerobic oxidation. Finally, the positive effect of the protection strategy on the photocatalytic oxidation of HMF is reported. Overall, our work greatly expands the application potential of the protection strategy via proposing an effective scale-up preparation method for commercially unavailable substrates and exploring more reaction types, especially under a reducing atmosphere. A grander blueprint to explore the protection strategy in biomass conversion can be imagined. [ABSTRACT FROM AUTHOR]

Ditopic di-o-quinone with a resorcinol bridge exhibits the ability to self-assemble in a reaction with copper, giving a cage-like binuclear complex that, due to the cofacially placed metal ions, is capable of encapsulation of different solvent molecules as guest ligands. Notably, the geometry of the internal cavity of this complex adjusts depending on the coordinating properties of the encapsulated molecule (mono- or bidentate). A feature of this species is that the cage-forming units are copper(II) bis-semiquinonate moieties, capable of undergoing ligand-centered redox transformations. Electrochemical and EPR spectroscopy studies showed that there is a channel for intramolecular electronic exchange interactions between the redox centres of the molecule. [ABSTRACT FROM AUTHOR]

Third phase formation is an undesirable event in a solvent extraction procedure. It is the splitting of the organic phase into two phases during the course of solvent extraction at a particular concentration of metal ions in the organic phase characterised by the limiting organic phase concentration (LOC). The occurrence of the third phase is due to the extensive aggregation of strongly polar reverse micelles formed beyond the LOC, leading to the de-mixing of polar aggregates from a non-polar diluent present in the solvent phase. In this work, the extraction behaviour of nitric acid and Nd(III) was studied in a solution of tetra-2-ethylhexyl diglycolamide (TEHDGA) in n-dodecane (n-DD) and was probed by dynamic light scattering, ATR-FTIR and NMR spectroscopy to understand the fate of the organic phase beyond the LOC. The studies revealed that the aggregation of reverse micelles in the organic phase increased gradually with an increase in the extraction of Nd(III) and nitric acid before the LOC, and remarkably increased in the third phase beyond the LOC. A significant increase in the aggregate size of the third phase beyond the LOC was due to the high loading of nitric acid and Nd(III) in the third phase, eventually leading to polydispersion of reverse micelles in third phase. Before poly-dispersion, the TEHDGA molecules present in the organic phase were completely transferred to the third phase beyond the LOC, facilitating a mode of recovery of the diluent, n-dodecane, from the solvent phase, even though the third phase formation was regarded as an undesirable event. [ABSTRACT FROM AUTHOR]

We disclose a metal-free, iodine-catalyzed oxidative C–H sulfenylation and selenation of alkenes, particularly 1,1-diarylethenes with diorganyl dichalcogenides in water for the cost-effective, highly atom-economical, and sustainable synthesis of valuable vinyl sulfides and selenides including some aggregation-induced-emission (AIE) active molecules. The transformation required only 10 mol% iodine as the catalyst and a very small amount of a green oxidant, H2O2 (0.3 equiv.), to afford the desired products in moderate to high yields of up to 96% under mild reaction conditions, i.e. 50 °C and an aerobic atmosphere. The products were further synthetically diversified to various novel classes of organic molecules. The notable advantages of this method over the previously developed ones for the C–H chalcogenation of 1,1-diarylalkenes are (a) a metal-free, energy-efficient, cost-effective and sustainable protocol for the synthesis of both vinyl sulfides and selenides, (b) use of inexpensive reagents such as iodine as the catalyst and H2O2 as the green oxidant, (c) water as the green reaction medium and water as the only byproduct, (d) a straightforward scale-up process up to the gram scale without any compromise on the reaction outcome, (e) very clean reactions (100% conversion) in multiple cases to afford pure vinyl sulfides/selenides without the requirement of a huge organic-solvent consuming column chromatographic purification technique, and (f) excellent green chemistry metrics such as high atom economy (>96%), atom efficiency (≥87%), carbon efficiency (>88%), and reaction mass efficiency (≥81%), a very low E-factor (≤4.5 g waste per g product), here the byproduct is nothing but water, and a very high EcoScale score (≥82) which revealed that this method is excellent in the context of green chemistry. Moreover, the catalyst iodine could be recovered after the reaction and recycled without any compromise on the reaction outcome which makes the process highly sustainable. Mechanistic studies revealed a radical pathway for this transformation. [ABSTRACT FROM AUTHOR]