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By using in-site generated formate, 2D HOFs of TCPP, with excellent stability and permanent porosity (BET surface area larger than 560 m2 g−1), have been obtained. The constructed 2D square-like TCPP-HCO2 grid sheets have shown considerable in-plane stability that comparable to the TCPP-based 2D MOFs, that can be exfoliated into atomically thin 2D nanosheets with efficient photocatalytic activity in aqueous system. These results are expected to shed light on the application-orientated one-pot synthesis for new kinds of multi-dimensional HOFs. [ABSTRACT FROM AUTHOR]

Precise revealing the mechanisms of excited‐state intermolecular proton transfer (ESPT) and the corresponding geometrical relaxation upon photoexcitation and photoionization remains a formidable challenge. In this work, the compound (E)‐4‐(((4H‐1,2,4‐triazol‐4‐yl)imino)methyl)‐2,6‐dimethoxyphenol (TIMDP) adopting a D‐π‐A molecular architecture featuring a significant intramolecular charge transfer (ICT) effect has been designed. With the presence of perchloric acid (35 %), TIMDP can be dissolved through the formation of a HClO4–H2O–OH(TIMDP)–N(TIMDP) hydrogen‐bonding bridge. At the ground state, the ICT effect is dominant, giving birth to crystals of TIMDP. Upon external stimuli (e.g. UV light irradiation, electro field), the excited state is achieved, which weakens the ICT effect, and significantly promotes the ESPT effect along the hydrogen‐bonding bridge, resulting in crystals of [HTIMDP]+⋅[H2O]⋅[ClO4]−. As a consequence, the mechanisms of the ESPT can be investigated, which distorted the D‐π‐A molecular architecture, tuned the emission color with the largest Stokes shift of 242 nm, and finally, high photoluminescence quantum yields (12 %) and long fluorescence lifetimes (8.6 μs) have achieved. These results not only provide new insight into ESPT mechanisms, but also open a new avenue for the design of efficient ESPT emitters. [ABSTRACT FROM AUTHOR]

Three salts: 3-amino-1,2,4-triazolinium (1+) hydrogen oxalate ( 1 ), 3-amino-1,2, 4-triazolinium (1+) hydrogen malonate ( 2 ), 3-amino-1,2,4-triazolinium (1+) hydrogen succinate ( 3 ) and one co-crystal: 3-amino-1,2,4-triazole-adipic acid ( 4 ) have been prepared and characterized by differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), IR, Raman, and single-crystal X-ray diffraction. Wherein, supramolecular motif in salts 1 , 3 and co-crystal 4 were dominant by triazole-acid and amino-acid heterosynthon, while salt 2 dominant by amino-triazole homosynthon in addition to triazole-acid heterosynthon, which attribute to the intermolecular hydrogen interactions within hydrogen malonate anion. These results have a close relationship with the ΔpKa between 3-ATZ and alkyl acids, we found that the ΔpKa is grate than 6.9, the formation of salt will be expected, while the formation of co-crystal usually with the ΔpKa less than 6.75. It is interesting that salts 2 and 3 show the phenomenon of proton transfer after melt, which lead to the stepwise sublimation of the two components. The differences between salts and co-crystal were also revealed by the solid-state vibrational spectroscopy (IR and Raman), Hirshfeld surface analysis and UV spectra. [ABSTRACT FROM AUTHOR]

In order to determine the effect of halogen bonding on supramolecular assemblies and photophysical properties of diaryl oxalates, diaryl oxalate itself and its derivatives with fluorine, chlorine, bromine, and iodine substituents in the p-position of phenyl rings were studied and compared. Their single-crystal structures were studied by geometrical analysis and theoretical calculation. The study reveals that different halogen bonds are formed with respect to different halogen atoms, such as C...F and X...X (bromine and iodine atoms) interactions, and molecular stacking modes would be affected by halogen bonds directly. Comparative studies of photophysical properties in dilute solution and solid state indicate that halogen substitutions would not affect the emission processes of diaryl oxalates in dilute solution; this is not the case for their solid state. This work has demonstrated that halogen bonds play an important role in regulating structures and photophysical properties of diaryl oxalates. [ABSTRACT FROM AUTHOR]

Abstract: Fabricating of melamine (MM)‐based multi‐component functional self‐assemblies have been investigated intensively. However, studies on protonated MM still in its infancy. Hence in this work, we studied the self‐assembly of protonated MM in different forms (1⋅ClO4− [MMH+⋅ClO4−⋅H2O], 2⋅Br− [MMH2+⋅2Br−⋅H2O], and 3⋅Cl− [MMH2+⋅2Cl−⋅H2O]) with various oxoanions (SO42−, NO3− and PO43−). Results revealed that the original anions ClO4‐, Br‐, and Cl‐, though not included in these self‐assemblies, are mainly responsible for the spectacular morphologies, from cuboids (1.SO42−) to prismoids (2.SO42−), sheets (3.SO42−), fibers (1.NO3−), rods (2.NO3−, 3.NO3−) and ribbons (1.PO43−, 2.PO43−, 3.PO43−). The crystalline phase and compositions of these self‐assemblies were found to be independent from the original protonated MM and the degree of protonation, while depend on the specific oxoanions. Therefore, the self‐assembly mechanism can be proposed. These results may provide an effective strategy for morphological control, especially for further development in protonated MM‐based functional materials. [ABSTRACT FROM AUTHOR]

Although synthetic efforts to prepare carboxylato-bridged tetranuclear iron(III) clusters have been well preformed, introducing of functional groups on the coordination ligands to tune the structural, spectroscopic and physical properties of the cluster remains unstudied. Using amino functionalized ligands bipy-NH 2 and O 2 CPh-NH 2 , we have prepared a new cluster 1 ([Fe 4 O 2 (O 2 CPh-NH 2 ) 7 (bipy-NH 2 ) 2 ]·HO 2 CPh-NH 2 ·(CH 3 CN) 3 ·C 2 H 5 OH·OH) via a new precise orientated strategy starting from iron(II) compound. The cluster was characterized by UV–Vis, IR and Mossbauer spectroscopy, X-ray crystallography, cyclic voltammetric and magnetic studies. Results have shown that the [Fe 4 (μ 3 -O) 2 ] 8+ core was disposed in a bent “butterfly” arrangement, and the adjacent cores were connected into 1-D chain via hydrogen-bonding contacts involving lattice OH − anion, HO 2 CPh-NH 2 and solvent molecules. This 1D chain exhibits strong antiferromagnetic interactions, and irreversible electron reduction of one iron(III) ion to iron(II) at EP.C = −1.77 V vs SCE. Remarkably, color change from reddish violet to bluish green have been observed for this cluster upon protonating the amino functional groups. [ABSTRACT FROM AUTHOR]

In this study, the potential of oxoanion separation with the ligands N-4-methylbenzyl-4-amino-1,2,4-triazole (L1), N-4-fluorobenzyl-4-amino-1,2,4-triazole (L2), N-4-hydroxy benzyl-4-amino-1,2,4-triazole (L3), and N-3-methoxy-4-hydroxybenzyl-4-amino-1,2,4-triazole (L4) was explored. The salts of sulphate, nitrate, and perchlorate were crystallized in the form of [HL1]+[HSO4]−·H2O, [HL2]+[HSO4]−·H2O, 2[HL3]+[SO4]2−·2(H2O), and 2[HL4]+[SO4]2−·H2O, [HL3]+[NO3]−·H2O and [HL4]+[NO3]−, and [HL3]+[ClO4]− and [HL4]+[ClO4]−, respectively. Competitive crystallization and competitive sulphate-binding experiments demonstrated special recognition of the sulphate–water clusters (in the forms of [HSO4−·H2O]n or [SO42−·H2O]n) via the parallel packed 3-D architectures of HL1+, HL2+, and HL4+ cations, which were far more effective and selective than the non-3-D structure of HL3+ cation. The observed selectivity for sulphate, nitrate, and perchlorate was found to be anti-Hofmeister. In addition, the selective separation of sulphate anions in seawater was investigated, which demonstrated the real-world application of the present strategy. [ABSTRACT FROM AUTHOR]

Three diaryl oxalate derivatives, bis(4-chlorophenyl)oxalate, bis(2, 6-dichlorophenyl)oxalate and bis(2, 4, 6-trichlorophenyl)oxalate, have been synthesized and characterized via X-ray single crystal diffraction, differential scanning calorimetry, thermogravimetric analysis and infrared spectra, for the purpose of studying the influence of chlorine substitution on the crystal structures of diaryl oxalate. This work has demonstrated that, depending on the position and number, chlorine substitution will influence the molecular geometries and stacking modes of diaryl oxalate by tuning the types and numbers of intermolecular interactions. [ABSTRACT FROM AUTHOR]

Investigations of spin-crossover in an iron(II) tris(diimine) system, based on the ligands L 1 (4,5-dimethy-2-(pyridine-2-yl)imidazole) and L 2 (1-acetic ethyl-2-(pyridine-2-yl)-imidazole), have been presented in this paper. The methyl groups at adjacent sites to the donor atoms in the ligand L 1 generated the crossover situation for complexes Fe( L 1 ) 3 (ClO 4 − ) 2 ( 1 ), Fe( L 1 ) 3 (BF 4 − ) 2 ( 2 ), Fe( L 1 ) 3 (PF 6 − ) 2 ( 3 ) and Fe( L 1 ) 3 (SbF 6 − ) 2 ( 4 ), while the acetic ethyl group at the non-coordinating NH site of the ligand L 2 resulted in an increase in the ligand field and generated a low-spin (LS) state for the complex Fe( L 2 ) 3 (ClO 4 − ) 2 ( 5 ). Complexes 1 and 5 were structurally characterized by single-crystal X-ray diffraction at different spin-states, while the phase purity of complexes 2 – 4 was confirmed by PXRD. Raman, IR and UV–Vis absorption spectra and magnetic properties of 1 – 4 were obtained, which revealed the influence of different counter anions on the spin transition temperatures. The blue-shift of IR and Raman spectra, red-shift and decrease in molar absorptivity of UV–Vis absorption spectra all follow the sequence 1 < 3 < 2 < 4 . [ABSTRACT FROM AUTHOR]

Investigation of spin-crossover in iron(II)-di(diamine) system, based on ligands L 1 , 4,5-dimethy-2-(pyridine-2-yl)imidazole, has been presented in this paper. The methyl group at the adjacent sites of the donor atoms in ligand L 1 can generate the crossover situation for the iron(II) tris(diimine) system. While for the iron(II)-di(diamine) system with L 1 , the results are complicated: complex 1 {Fe( L 1 ) 2 (SCN) 2 } displays paramagnetic behavior while 2 {Fe( L 1 ) 2 (SeCN) 2 } is in crossover situation. The difference was attributed to the various ligand field strength of SCN − and SeCN − , which also resulted to the blue-shift of IR and Raman spectra, as well as red-shift and decrease in molar absorptivity of UV–Vis absorption spectrum. [ABSTRACT FROM AUTHOR]

Two iso-structural two-dimensional (2D) porous coordination polymers, which formulated as [Fe(1,3-di(4-pyridyl)propane) 2 (NCX) 2 ] 2 (X = S [ 1 ], Se [ 2 ]) and featured 2-fold interpenetration, have been synthesised and characterized. Crystal structure, Hirshfeld surfaces analysis and magnetic properties of them were described. The basic-unit of 1 and 2 was the 2D rhombic grids [2 × (4, 4)] network, and the intermolecular interactions in the crystals were dominated by C–H…π, H–H and C–H…S (Se) contacts. The stronger ligand field strength of SeCN − than that of SCN − resulted to different magnetic properties: compound 1 shows paramagnetic property while 2 display displays an incomplete SCO transition approximately 30% conversion of high-spin (HS) to low-spin iron(II) sites with transition temperature of 100 K. [ABSTRACT FROM AUTHOR]

The quantitative visualizations and comparisons between the four pyrazinamide (PZA) polymorphs (α, β, γ and δ) have been investigated by graphical tools based on three-dimensional Hirshfeld surfaces and two-dimensional fingerprint plots. The comparisons were performed in terms of crystal structure, d, Shape index, Curvedness and d surfaces, and fingerprint plots. The results revealed that the α and γ forms featured with 1D chains and the π···π stacking motifs belong to γ-motif, rich in π···π interactions and form infinite face-to-face stacks, β and δ forms featured with dimer unit and the π···π stacking motifs belong to γ- and herringbone-motif, respectively, the herringbone motif of δ form rich in C-H···π and edge-to-face interactions. We also correlated the phase transformation points of α, β, and δ PZA forms with the ratio of the percentage surface coverage of the N-H···O hydrogen bonds over that of the N-H···N hydrogen bonds, and found a negative correlation. [ABSTRACT FROM AUTHOR]

Crystal structural investigations and Hirshfeld surface analysis of three methoxy- and methyl-substituted indole-3-acetonitriles (IAN) (4-OCH-IAN, 5-OCH-IAN and 7-CH-IAN) are reported in this work. Their structures were characterized by infrared spectra, elemental analyses, NMR spectra, differential scanning calorimetry, thermogravimetric analyses, and hot stage microscopy. The Hirshfeld surface analysis in terms of intermolecular interactions and π···π stacking motifs of the three substituted IANs was investigated in detail, and the results revealed that the different kinds of substituent groups as well as different substituted positions have a significant effect on the crystal structures, molecular π···π stacking motifs, melting points, and the types of intermolecular interactions. [ABSTRACT FROM AUTHOR]

A new spin crossover coordination polymer (SCO-CPs) of Fe(II)-4,4′-bipyridine (4,4′-bipy) family: {Fe(4,4′-bipy) 2 (H 2 O) 2 }·(4,4′-bipy)· 8(H 2 O)·2(ClO 4 ) ( 3 ), which displays half spin transitions between 100 and 300 K, has been synthesized and structurally characterized. Compound 3 featured with two-dimensional (2-D) grids connected by hydrogen bonds and π … π packing between one-dimensional (1-D) chains, the 2-D grids expand to three-dimensional (3-D) architecture supported by a “S-shaped holder” involving lattice 4-4′-bipy, water molecules and perchlorate anion. We compared 3 with the other two analogous complexes: ({Fe(4,4′-bipy) (H 2 O) 2 (NCS) 2 }·4,4′-bipy, 1 and {Fe(4,4′-bipy) 2 (NCS) 2 }·mSolv, 2 ) through Hirshfeld surfaces analysis, which revealed that the low ligand field strength (NCS − ) and lone-pair…H contacts contribute to the stabilization of HS (high-spin) state of the Fe(II) ion, while the high ligand field strength (4,4′-bipy) and strong intermolecular contacts (hydrogen bonds and π … π packing interactions) make for the LS (low-spin) state. [ABSTRACT FROM AUTHOR]

Guest molecule dependent crystal structures, intermolecular interactions and magnetic properties of an iron (II) coordination polymer ( 2 ) with 4,4′-dipyridyl disulfide (4-DPS) ligand have been investigated. Polymer 2 {[Fe(NCS) 2 (4-PDS) 2 ]·2(2,5-DCP)} n was derived from polymer 1 [Fe(NCS) 2 (4-PDS) 2 ·4H 2 O] n through the change of water molecules by 2,5-dichloropyrazine molecules (2,5-DCP). This substitution leads to the change of the polymer motif from di -triangle to rectangle, and the decrease of longer contacts (S–H, N–H, C–H and H–H) while increase of the π ⋯ π (C–C) contacts in the crystal. These above changes then tuned the electronic structure of the iron (II) ion from high spin (HS) state ( 1 ) to the onset high spin (HS)–low spin (LS) transition ( 2 ), and resulted intermolecular anti-ferromagnetic interactions at lower temperatures. [ABSTRACT FROM AUTHOR]

Crystal structural investigations and Hirshfeld surface analysis of three halogen atoms (4-Cl, 6-Cl and 4-Br) substituted indole-3-acetonitrile (IAN) were reported in this work. The structures of the present three compounds were characterized by Infrared spectra, Elemental analyses, NMR spectra, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA) and hot stage microscopy (HSM). The Hirshfeld surfaces analysis in terms of crystal structure, intermolecular interactions and π⋯π stacking motifs were performed. We found that the different kinds of halogen atoms and the different substituted positions have a significant effect on the crystal structures, molecular π⋯π stacking motifs, melting points, and the nature of intermolecular interactions for IANs. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two copper complexes derived from polypyridine and salicylide ligands have been prepared. [•] Intermolecular interactions in them have been investigated by using Hirshfeld surfaces. [•] These two complexes can intercalation with DNA. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new copper (II) complex with hetero N- and O-donor ligands has been prepared. [•] The coordinated water molecules play a key role in the construction of crystal structures. [•] The intermolecular interactions and solid state luminescent properties have been investigated. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two new complexes from 6-methylnicotinic acid (6-MNA) have been presented. [•] Influences of metals on 6-MNA through Hirsheld surfaces have been investigated. [•] Intermolecular interactions of complexes have been quantificationally visualized. [ABSTRACT FROM AUTHOR]

For the development of dispersible tablets of itraconazole (ITR), techniques of thermal, Raman spectroscopy, and isothermal stress testing (IST) were used to assess the compatibility of ITR with selected excipients. Initially, differential scanning calorimeter (DSC) was used to evaluate the compatibility. Raman spectrum of drug-excipient mixture was also compared with that of pure drug and excipient. Compatibility of excipients defined in the prototype formula was tested using IST. Based on the DSC results alone, PEG-4000 was found to exhibit interaction with ITR. However, the results of Raman and IST studies showed that all the excipients used in the formula were compatible with ITR. Overall, compatibility of excipients with ITR was successfully evaluated using the combination of DSC, Raman spectroscopy, and IST techniques. [ABSTRACT FROM AUTHOR]

Highlights: [•] Two new meta-stable forms of 6-chloroquinolin-2(1H)-one have been prepared and characterized. [•] The new meta-stable forms were induced by 3D inorganic anions. [•] We compared the stable form with the meta-stable forms by various methods. [ABSTRACT FROM AUTHOR]

Highlights: [•] Three new co-crystals of pyridine-2-carboxamide have been synthesized and characterized. [•] It is the length of carbon chain of co-crystal formers that control the co-crystal structure. [•] We investigated detailed the interactions by Hirshfeld surface solid-state vibrational spectroscopy. [ABSTRACT FROM AUTHOR]

Five supramolecular assembly complexes: 2-hydroxypropane-1,3-diammonium-perchlorate-18-crown-6 ([C3H12N2O-(18-crown-6)2]2+·2[ClO4]−, 1); 2-hydroxypropane-1,3-diammonium-tetrafluoroborate-18-crown-6 ([(C3H12N2O)2-(18-crown-6)3]2+·2[BF4]−, 2); 4-methylanilinium perchlorate-18-crown-6 ([C7H10N-(18-crown-6)]+·[ClO4]−, 3); 4-iodineanilinium-tetrafluoroborate-18-crown-6 ([C6H7NI-(18-crown-6)]+·[BF4]−, 4); 4-methylanilinium tetrafluoroborate-18-crown-6 ([C7H10N-(18-crown-6)]+·[BF4]−, 5), for the investigation of the influence of different inorganic anions on the orientation of ammonium cation and host–guest interaction of crown ethers, have been synthesized and characterized. The results revealed that ClO4 − anion lead to the 2:1 composition of crown and ammonium cation in monoclinic space group and 3:2 composition of crown and ammonium cation in the presence of BF4 − anion for double-anilinium system (complexes 1 and 2). While for the single-anilinium system (complexes 3, 4, and 5), the different inorganic anions lead to quite different orientation of the ammoniums in orthorhombic space group. We also studied the TGA/DSC properties, Raman spectrascopy and hot stage microscopy for the five complexes. [ABSTRACT FROM AUTHOR]

Four rotator–stator assembly complexes: benzoic-4-methylammonium-tetrafluoroborate-15-crown-5 ([C8H10NO2-(15-crown-5)]+[BF4]−, 1); benzoic-4-methylammonium-perchlorate-15-crown-5 ([C8H10NO2-(15-crown-5)]+[ClO4]−, 2); benzoic-4-methylammonium-tetrafluoroborate-18-crown-6 ([C8H10NO2-(18-crown-6)]+[BF4]−, 3); benzoic-m-ammonium-tetrafluoroborate-18-crown-6 ([C7H8NO2-(18-crown-6)]+[BF4]−, 4), for the investigation of the supramolecular assembly and host–guest interaction of crown ethers, have been synthesized and characterized. The results revealed that the variation of crown ethers, the substituent position of carboxyl group, as well as the different kinds of inorganic anions all can lead to quite another geometry and directionality of both the anilinium rotors and crown ether stators, which lead to entirely different supramolecular architectures. It is interesting that the optimal distances from the mean O-plane where found for the 18-crown-6 macrocycle with the ammonium cation, and the conformation of the macrocycle was badly affected in complexes with shorter or longer distances. We also studied the Raman spectroscopy of the five complexes, which give further inspection of the intermolecular interactions. [ABSTRACT FROM AUTHOR]

An investigation into the substituent effect of halogen atoms (F, Cl, Br) on the crystal structure of indole-3-carboxylic acid (ICA) was prepared in this work. The investigation was done through the aspect of crystal structure, intermolecular interactions and π…π stacking motifs with the assistance of infrared spectra, elemental analyses, NMR spectra, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA) and hot stage microscopy (HSM) measurements. The results revealed that the different kinds of halogen atoms and the different substituted positions have a significant effect on the crystal structures, molecular π…π stacking motifs and the kinds of intermolecular interactions. We further correlated the melting points of the ICAs with the H–H, O–H and X–H (X = F, Cl, Br) interactions, and found a positive correlation between them. [ABSTRACT FROM AUTHOR]

In-situ Attenuated total reflectance Fourier transform infrared (ATR-FTIR), focused beam reflectance measurement (FBRM) and particle video microscope (PVM) have been used simultaneously in this work to monitor the concentration, supersaturation, chord length distribution, and crystal habit, respectively, during a cooling crystallization process of Methyprednisolone Hemisuccinate (MPHS) from ethanol system. We developed a new calibration method based on peak ratios for the assessment of the concentration, solubility, and supersaturation in the 20–60°C temperature range. The crystallizations were conducted at two concentrations (7.5 and 9.5% w/w) with three different cooling rates (0.3, 0.5, and 0.7 K/min). The lower concentration was chosen within the constructed calibration range while the higher one was outside the calibration range and it was used to examine the extrapolating and predicting ability of the constructed calibration curves. The metastable zone widths (MSZW), supersaturation at nucleation, and the number of fine particle chord length of MPHS were all increased with the cooling rate, while the number of the larger chord length decreased with the increasing of the cooling rate. [ABSTRACT FROM AUTHOR]

Highlights: [•] The fourth CuII–azido-pyrazine complex has been synthesised and characterized. [•] The crystal structure display novel 3D-42.63.8-topology with 2D honeycomb layer. [•] The complex exhibit strong antiferromagnetic coupling. [ABSTRACT FROM AUTHOR]

Abstract: An investigation of supramolecular synthons of p-hydroxybenzoic acid (PHBA) has been carried out in this work. Three different kinds of compounds derived from PHBA (hydrate (1), co-crystal (2) and salt (3)) have been synthesized and characterized by single-crystal X-ray diffraction, infrared spectroscopy, differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA). A thorough structural investigation revealed the different supramolecular synthons patterns of the three compounds: hydrate (1)—displays 1-D supramolecular sheet completed by water molecules; co-crystal (2)—displays square grid structure completed by hetero-dimeric unit; and salt (3)—forms hetero-dimeric unit and displays infinite zigzag striped structure. We further prepared Hirshfeld surfaces for compounds 1–3 as well as PHBA, accompanied by vibrational spectroscopy, for the in-depth studies of intermolecular interactions in their solid-state forms. [Copyright &y& Elsevier]

Three new pharmaceutical co-crystals: 1 PZA-MA (malonic acid), 2 PZA-SA (succinic acid, a new polymorph of a reported one), and 3 PZA-GA (glutaric acid) have been prepared and characterized by differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), and single-crystal X-ray diffraction. Wherein, PZA formed 1:1 co-crystals with MA and GA by acid–amide and acid–py heterosynthon, while it formed 2:1 co-crystal with SA by amide–amide homosynthon in addition to acid–amide and acid–py heterosynthon. Their melting points follow the order, PZA-GA < PZA-MA < PZA-SA, which are lower than the melting points of the individual components. Hirshfeld surface analysis revealed that N–H···O hydrogen bonding and π···π interactions for PZA in them follow the order: PZA-MA > PZA-SA > PZA-GA, while H–H and O–O interactions follow the order: PZA-MA < PZA-SA < PZA-GA. We also compared the Hirshfeld surfaces of the present co-crystals with the nine reported PZA co-crystals, which obtained important results. The studies of the solubility and dissolution showed a semiempirical inverse relationship with the melting point: the solubility follows the order, PZA-SA < PZA-GA < PZA-MA and dissolution rate follows the order, PZA-SA < PZA-MA < PZA-GA. Three co-crystals, PZA−MA (1), PZA−SA (2), and PZA−GA (3), have been prepared and characterized by DSC, TGA, single-crystal X-ray diffraction, and the Hirshfeld surface. The three co-crystals were connected through acid−amide and acid−py supramolecular heterosynthon, and exhibited a superior solubility and intrinsic dissolution rate than did PZA. [ABSTRACT FROM AUTHOR]

A process mathematic model of seed batch desupersaturation experiments and induction time experiments for the investigation of growth and nucleation kinetics of biapenem through an antisolvent procedure in water/ethanol (antisolvent) system was developed in this work. The kinetic parameters for growth and nucleation were estimated by using in situ technology: attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy for solute concentration, focused beam reflectance measurement (FBRM) for CLD moments, and particle vision and measurement (PVM) for particle image measurement. The challenging aspect for the development of this model was the recovery of crystal size distributions (CSDs) from the chord length distribution (CLD) moments; batch experiments were designed for the estimation of this relationship. The mathematic model in this work was confirmed by a comparison between model predictions and experimental data. [ABSTRACT FROM AUTHOR]

Abstract: A novel N-donor bridging receptor R : 4,4′-methanediylbis(2-ethyl-5-methyl-1H-imidazole) has been synthesized from 2-ethyl-4-methyl-1H-imidazole and formaldehyde in the presence of potassium hydroxide. This receptor then formed complexes with different transition metals ([Co(NO3)2, CoCl2, Ni(NO3)2 and CuCl2]) in different solvent systems and obtained five different complexes. Wherein, the complex formation of R with Co(NO3)2 resulted in two different structures in methanol and acetonitrile, respectively. A thorough structural investigation of the present receptor and the resulted five complexes show that the NH group of the receptor, the organic anions and solvent molecules play a key role in the construction of the five intriguing architectures. We also prepared molecular Hirshfeld surface and fingerprint plot for R as well as the five complexes, which revealed the influences of different metals to the coordinate behavior of R in terms of intermolecular interactions. [Copyright &y& Elsevier]

The complex [Cu2(μ-L)2]. DMF (L = 2, 2'-[1-(2, 4, 6-trichlorophenyl)-1H-1, 2, 4-triazole-3, 5-diyl] diphenolate) has been prepared and its structure determined. The two CuII ions are four-coordinated in a planar structure, with the DMF molecule wrapped in the 'wings' of ligand L. Hirshfeld surface and fingerprint plots reveal that the complex structure is stabilised mainly by H···H, C-H ... Cl, C-H···π,π···π and lone-pair···π (C-Cl) intermolecular interactions. [ABSTRACT FROM AUTHOR]

The complex [N(CH3)4]3[Mn3Zn2(3,5-dibromosalox)3O(N3)6Cl2] has been synthesised and characterised. It crystallises as two independent molecules and exhibits a planar [MnIII3-(μ3-oxo)] core as well as μ2-η1:η1-azide bridging geometry. DNA binding studies show that the complex binds with DNA through intercalation. [ABSTRACT FROM AUTHOR]

Two new 1-D coordination polymers [ M (3-Bzpy)(N(CN))] ( M = Cd ( 1), Cu ( 2), 3-Bzpy = 3-benzoylpyridine) have been synthesized and structurally characterized by single-crystal X-ray diffraction and IR. Single-crystal X-ray diffraction reveals that the complexes 1 and 2 are isostructural and all crystallize in monoclinic P2/ c space group with cell dimensions: a = 6.3889(16) Å, b = 7.6496(12) Å, c = 26.767(6) Å, β = 99.131(19)°, V = 1291.6(5) Å, Z = 2 for 1 and a = 6.4483(9) Å, b = 7.5449(10) Å, c = 25.965(4) Å, β = 98.559(10)°, V = 1249.2(3) Å, Z = 2 for 2. Structure analysis manifest that 1 and 2 are all 1-D chains structures which parallel to the crystallographic b axis through end-to-end coordination by bidentate bridging dicyanamide ligands. Magnetic property of complex 2 was further investigated. Graphical Abstract: The paper is about synthesis, crystal structure and magnetic property of two new 1-D coordination polymers. Perspective view down the a-axis of complex 1 with thermal ellipsoids drawn at the 50% probability level [Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

Iron(II)-triazole coordination polymers have attracted considerable interest for their synthetic versatility, which allows tuning their spin-crossover (SCO) properties. Embedding SCO solid particles in sponge matrices is a simple, powerful, and generic approach to construct processable SCO materials. Here, we have studied a series of magnetic frameworks based on partial ligand substitution by using different chemical mixtures of two organic ligands, yielding four isostructural coordination polymers. The integration of the hygroscopic SCO material has endowed the composite sponge with the ability to capture moisture under ambient conditions. In particular, not only does a spin-crossover transition during absorption occur, but also a color variation has been achieved by varying humidity. The consequences of cooperativity and the exposed surface of the composite sponge on the spin transition were evaluated and the most promising materials among them were screened. This work provides guiding significance for the fabrication and practical application of spin-crossover-sponge materials. [ABSTRACT FROM AUTHOR]

CO2 capture and storage have been regarded as promising concepts to reduce anthropogenic CO2 emissions. However, the high cost, inferior adsorption capacity, and higher effective activation temperature of traditional sorbents limit their practical application in efficient CO2 capture. Here, a C‐S‐H@ZIF‐8 (C‐S‐Z) sorbent is fabricated by in situ growth of the ZIF‐8 shell on the C‐S‐H (calcium‐silicate‐hydrate) surface for ultra‐high CO2 adsorption and storage. Among the C‐S‐Z, the outer ZIF‐8 shell acts as a transport channel that promotes CO2 absorption toward the underlying C‐S‐H substrate for accelerated carbonation while preventing nitrogen and water from reaching the interior C‐S‐H. As a consequence, C‐S‐Z possesses the merits of ample pyrrolic nitrogen, porous structure, and ultra‐high surface area (577.18 m2 g−1), that contribute to an ultra‐high CO2 capture capacity, reaching 293.6 mg g−1. DFT calculations show a high CO2 adsorption energy and the mineral carbonation is dominant by the adsorption process. In particular, the advantages of the outstanding adsorption capacity, low cost, and high CO2 selectivity make this C‐S‐H‐based sorbent hold great potential in the practical application for direct air CO2 capture and storage. [ABSTRACT FROM AUTHOR]

Owing to the critical roles it plays for both structure and functionality, hydrogen bonding has high hopes for the orientated applications in hydrogen‐bonded organic frameworks (HOFs). Here in this work, a hydrogen‐bonding strategy is performed for adjusting the structure and functionality of a heme‐like ligand meso‐tetra(carboxy‐phenyl)‐porphyrin (TCPP) with co‐former 1,3‐di(4‐pyridyl) propane (1,3‐DPP). A 3D dynamic HOF TCPP‐1,3–DPP, with permanent porosity is obtained. For this HOF, the two components form novel robust 1D porous stripes, with the 1,3‐DPP molecules acting as the lining for the pores that are confined within the region between adjacent carboxyphenyl moieties of TCPP. This confinement has tuned the affinities of TCPP from hydrophobic into hydrophilic. Interestingly, the 1D stripes are further stacked by weak π...π interactions into a 3D framework, the latter is highly dynamic with 1D stripes sliding back and forth, upon pressurized and water adsorption in the solid‐state under ambient conditions, respectively. The activated TCPP‐1,3–DPP has a Brunauer–Emmett–Teller surface area of 258 m2 g−1, and shows a maximum adsorption capacity about 9.8% for water during the adsorption–desorption cycles, demonstrating a promising candidate for the real‐world application in effective dehydration of industrial gases under ambient conditions. A 3D dynamic hydrogen‐bonded organic framework TCPP‐1,3–DPP, which is composed of 1D porous stripes, shows permanent porosity and highly affinity to water. The activated species exhibit a maximum adsorption capacity about 9.8% for water during the adsorption–desorption cycles, demonstrating a promise for the real‐world application in effective dehydration of industrial gas under ambient condition. [ABSTRACT FROM AUTHOR]

Metal–organic framework nanosheets (MONs) are expected to turn the cornerstone of integrated electronic and optoelectronic devices owing to their unique properties. However, as the premise and guarantee for research applications, adjustable preparation and accurate control of MONs remain a challenge. Here in this work, we demonstrate that the sizes and colors of MONs can be tuned by subtle control of the solution pH (from 3 to 11) during the precursor preparation. Where the variation of the sizes of MONs from nano-scale (lateral size smaller than 200 nm) to micro-scale (lateral size larger than 10 μm) was achieved, which was accompanied by the continuous color variation from green to gray for the solid-state samples, and from orange to pink for the colloidal suspensions. As a result, linear correlations between the sizes and colors of the MONs with the solution pH were established. Laser irradiation experiments further demonstrated the inverse relationship between the fluorescence intensity of MONs and the pH, providing a fairly good strategy for the controlled preparation and color adjustment of MONs. [ABSTRACT FROM AUTHOR]

Photoreversible color‐switching materials, which can reversibly change color in response to external light stimuli, have attracted increasing attention for their applications in time‐sensitive information storage and optical data storage fields. But most of the related materials are dyes or redox compounds with ultraviolet as the light source, dramatically limiting the cycling stability during discoloration processes. To address this problem, a near‐infrared (NIR)‐responsive rewritable paper via doping layered Co‐metal–organic frameworks (MOFs) into the stable polyvinylidene fluoride matrix is reported for the first time. Layered Co‐MOF shows a rapid color‐switching characteristic between orange and black blue upon NIR illumination on/off because of the interlayer spacing changes. Benefiting from the soft network structures of the matrix, Co‐MOF can be homogeneously distributed to deliver an outstanding reversibility performance, including rapid response, coloration in a short period, and decoloration within about 3 min in ambient air. The fabrication of new photoreversible color switching system holds great potential in communication security, which offers a viable pathway to achieve ink‐free photoreversible printing. [ABSTRACT FROM AUTHOR]

Efficient atmospheric water harvesting has been a focal point in the broad spectrum of water collection sources, to alleviate the challenges caused by water shortage. Herein, we report a systematic approach focused on preparing a polymer hydrophobic–hydrophilic gel, doped with super hygroscopic materials (SHMs), enabling high moisture capture, color response, and in situ moisture storage. The hybrid gel quickly achieves a water uptake of 100% under different humidity levels from 43% to 98%. The hybrid gel achieves not only the capture of moisture but also the response of an obvious color change from blue to pink, visible to the naked eye. The interesting properties of the hybrid gel give rise to a wide range of possibilities in design and engineering for humidity capture response and detection application, providing bright prospects for the next generation of atmospheric water harvesting systems. [ABSTRACT FROM AUTHOR]

Humidity visualization is of significant importance across both the living systems and the industrial processes, which remains a huge challenge. Herein, for the first time, a hydrophilic sponge, which is composed of rigid gel and super hygroscopic material, has been demonstrated capable of all‐weather humidity visualization in a portable, convenient, economical, and in situ manner. This promising aspect is attributed to the effective all‐weather humidity capture and various color display as a response to the humidity capture capacity, of the super hygroscopic material; as well as the rapid humidity transport and excellent humidity storage ability provided by the porous rigid gel. As a consequence, combined with a smartphone, the invisible information on the environment's relative humidity levels, on the one hand, can be correlated qualitatively with the specific color display of the sponge; on the other hand, it can be correlated quantitatively with the specific color intensity, providing a pretty good smart model for humidity visualization in various complex environments. The present humidity visualization technology may open up a new avenue for the development of novel humidity sensors with a wide range of practical applications. [ABSTRACT FROM AUTHOR]

Four new complexes based on the 4-(4-carboxyphenyl)-1,2,4-triazole (Hcpt) ligand, {[Co(cpt) 2 (H 2 O) 4 ]·H 2 O}( 1 ), {[Cr(cpt) 2 (H 2 O) 4 ]·10H 2 O}( 2 ), {[Fe(cpt) 2 (H 2 O) 4 ]·10H 2 O}( 3 ), {[Zn(cpt) 2 (H 2 O) 2 ]}( 4 ) have been synthesized and characterized by elemental analysis, single crystal X-ray diffraction and TGA. For complexes 1 , 2 , and 3 , they almost have the same coordination mode that only one nitrogen atom of triazole are involved in the coordination, while in the complex 4 , only the group COO − participates in the coordination. In the crystal structure of 1 , each structural unit[Co(cpt) 2 (H 2 O) 4 ] is linked to another by hydrogen bonding formed by the lattice water molecules, thus forming a one-dimensional chain structure; In the crystal structure of 2 or 3, each structural unit[Cr(cpt) 2 (H 2 O) 4 ] or [Fe(cpt) 2 (H 2 O) 4 ] forms a two-dimensional layered structure by intermolecular hydrogen bonds from the coordinated water molecule and the group COO − . The results of thermogravimetric analysis show that the loss of lattice water and coordinated water molecules in 1 , 2 and 3 is below 120 °C, while the loss of coordinated water molecules in 4 is in the temperature range of 190–260 °C. Hirshfeld surface shows that the N H⋯O hydrogen bonding interaction plays a significant role towards the conformation of the basic structure of these complexes. [ABSTRACT FROM AUTHOR]

Because of the differences in the position and degree of fluorine substitution, four fluorinated DSA (9,10-distyrylanthracene) derivatives, namely 9,10-bis(4-fluorostyryl)anthracene (4-BFSA), 9,10-bis(3-fluorostyryl)anthracene (3-BFSA), 9,10-bis(3,5-difluorostyryl)anthracene (BDFSA) and 9,10-bis(3,4,5-trifluorostyryl)anthracene (BTFSA), display different crystal packing and photophysical properties in the solid state. Furthermore, the photophysical properties in solution have been investigated. The results show that all the four compounds exhibit tunable aggregation-induced enhanced emission (AIEE) properties. Notably, DSA, 4-BFSA, 3-BFSA and BDFSA display solvatochromic properties. The relationship between their structures and photophysical properties was further discussed. This work has demonstrated that depending on the amount and position, fluorine substitution can tune the structures and photophysical properties of DSA effectively. [ABSTRACT FROM AUTHOR]

Two complexes 1 [Cu(L1)2(H2O)2]·2H2O and 2 [Co(L2)2 (H2O)4]·4H2O formed by hetero N- and O-donor ligands 1-methyl-3-imidazole-4-carboxylic acid (L1H) and 2-methyl-5-pyridine carboxylic acid (L2H) have been synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. These two complexes consist of a 2:1 ratio of ligand to metal ion. The analysis of Hirshfeld surfaces and crystal structures reveal that O‒H···O hydrogen bond interactions and C‒H···π intermolecular interactions support the three-dimensional supramolecular structures of complexes 1 and 2. Meanwhile, the coordinated water molecules and lattice water molecules play a key role in the construction of their crystal structures. [ABSTRACT FROM AUTHOR]

Two new mononuclear iron (II) coordination complexes: Fe(L1)2(SCN)2(1, L1:5-dimethylether-4-(4-methylphenyl)-3-(2-pyridinyl)-1,2,4-triazole) and Fe(L2)3(ClO4)2(2, L2:1-ethyl acetate-2-(2-pyridinyl)-imidazole), for the exploration of spin-crossover compounds have been synthesized and characterized. Structural analysis revealed that the framework of complex1is featured with 1-D chain structure connected by weak π···π interactions between the adjacent L1ligands, while complex2featured with various kinds of weak intermolecular hydrogen bonding interactions between Fe(L2)32+cation and ClO4−anion, which lead to a close crystal packing. The intermolecular interactions have shown a significant influence on the physical properties, and magnetic measurements of complexes1and2in the solid state at the room temperature revealed that the weak intermolecular interactions in1resulted in HS (high-spin) state, while the strong interactions in2lead to LS (low-spin) state over the whole temperature range. [ABSTRACT FROM AUTHOR]

The compound {[Zn(μ-dicyanamide)(pyrazinamide)](pyrazinamide)} has been synthesized and further characterized by elemental analysis, single-crystal X-ray diffraction, and thermogravimetric analysis. Structural analysis revealed that the dicyanamide anion acted as bridging ligand in a μ-1,5 mode, resulting a polymeric 1-D chain structure. The pairwise N3-H3B···N1 and N9-H9B···N7, N3-H3A···O2 and N9-H9A···O1, N3-H3B···N7 and N9-H9B···N1 multiple hydrogen bonding interactions, impart enhanced stability to supramolecular structures. Hirshfeld surfaces and fingerprint plots were applied to arrive at the same conclusion, which is stabilised mainly by H-H, N-H, O-H interactions. DNA binding studies showed that the compound had interacted with DNA. [ABSTRACT FROM AUTHOR]

A series of Fe(II) complexes with (ClO4)−(SeCN)−, (ClO4)−(SCN)−, (Fe2OCl6)2−, and 2(BF4)−counter-anions for complexes1–4, derived from dmbpy (4,4′-dimethyl-2,2′-bipyridine), were prepared. The single-crystal studies and the Hirshfeld surfaces analysis revealed that the (Fe2OCl6)2−anion results more distortional octahedral geometry of the cation than other anions. In particular, the (ClO4)−(SCN)−and (Fe2OCl6)2−anions lead to complexes2and3stabilized via C-H···π interactions and π···π interactions, which were not found in the other two complexes. However, the double-chain structure of complex4was formed by C-H···F and C-H···C hydrogen bonds interactions. Due to the influence of different anions, magnetic susceptibility measurements showed that complex1was in high-spin (HS) state and complex2was in low-spin (LS) state. [ABSTRACT FROM AUTHOR]

Four novel lanthanide compounds based on the 4-(4-carboxyphenyl)-1,2,4-triazole ligand (Hcpt), {[Pr2(cpt)4(H2O)10]·10H2O·2ClO4} (1), {[Ln(cpt)2(H2O)2(OH)]·4H2O}n (Ln = Er(2), Lu(3)), and {[Sm(cpt)2(CH3CH2OH)(H2O)3]·ClO4}n (4), have been obtained under hydrothermal conditions and further characterized by elemental analysis, single-crystal X-ray diffraction and thermogravimetric analysis. Compound 1 exhibits a discrete dinuclear structure constructed by one cpt− ligand coordinated to two Pr3+ ions and another cpt− ligand coordinated to more than one Pr3+ ion. Compounds 2 and 3 are isomorphous and every cpt− ligand coordinates to two Ln3+ ions, resulting in a polymeric 1-D chain structure. Different from the above compounds, the nitrogen atoms of triazole are also involved in the coordination of compound 4. One cpt− ligand coordinates to two Sm3+ ions and another cpt− ligand coordinates to more than one Sm3+ ion, meanwhile, the nitrogen atoms of triazole coordinate to the third Sm3+ ion, resulting in a 2-D polymeric network structure. The luminescence properties of compound 4 were characterized, and the results revealed that it exhibited characteristic Sm3+ emission in the yellow region. [ABSTRACT FROM AUTHOR]

Four DSA (9,10-distyrylanthracene) derivatives, namely 9,10-bis(4-fluorostyryl)anthracene (BFSA), 9,10-bis(4-chlorostyryl)anthracene (BCSA), 9,10-bis(4-bromostyryl)anthracene (BBSA) and 9,10-bis(4-iodostyryl)anthracene (BISA) have been synthesized and characterized via single crystal X-ray diffraction, powder X-ray diffraction, differential scanning calorimetry, photoluminescence spectroscopy, ultraviolet-visible absorption spectroscopy, solid fluorescence quantum yield measurement and other techniques, for the purpose of studying the influence of halogen atoms on the structures and photophysical properties of 9,10-distyrylanthracene. The results indicate that the introduction of halogen atoms into DSA significantly influences the molecular geometries and stacking modes in the crystals. The photophysical properties in solution and in the crystalline state of the five compounds were comparatively investigated, and the relationship between the crystalline state emissions and crystal structures was further discussed. This work has demonstrated that the introduction of halogen atoms into DSA could influence the molecular packing and molecular geometries in the crystals and endow them with different photophysical properties. [ABSTRACT FROM AUTHOR]

We here reported a series of co-crystal structure of pyrazinamide (PZA) with m-hydroxybenzoic acid (MHBA), p-hydroxybenzoic acid (PHBA) and 3,4-dihydroxy benzolic acid (3,4-DHBA) and obtained three co-crystals (co-crystal 1- 3, respectively) under the same conditions. These crystal structures were characterized by single-crystal X-ray diffraction, IR spectra, thermogravimetric analyses, differential scanning calorimetry, and Raman spectrum analysis. The images of single crystal diffraction revealed that 1 was a 1:1 (PZA:MHBA) co-crystal, 2 was a 1:1 (PZA:PHBA) co-crystal, and 3 was a 1:1 (PZA:3,4-DHBA). The strong O-H···O, N-H···O hydrogen bonding interactions between PZA and hydroxyl-substituted benzoic acid primarily made the structure of co-crystals stabilized. Hirshfeld surface and fingerprint plots of the three co-crystals showed that the structures were stabilized by H···H, O-H···O, N-H···O C-H···π, and π···π intermolecular interactions. [ABSTRACT FROM AUTHOR]