Synthesis, crystal structure and Hirshfeld surface analysis of (3Z)-4-[(4-amino-1,2,5-oxa-diazol-3-yl)amino]-3-bromo-1,1,1-tri-fluoro-but-3-en-2-one.

In the title compound, C6H4BrF3N4O2, the oxa-diazole ring is essentially planar with a maximum deviation of 0.003 (2) Å. In the crystal, mol-ecular pairs are connected by N-H⋯N hydrogen bonds, forming dimers with an R 2 2(8) motif. The dimers are linked into layers parallel to the (10) plane by N-H⋯O hydrogen bonds. In addition, C-O⋯π and C-Br⋯π inter-actions connect the mol-ecules, forming a three-dimensional network. The F atoms of the tri-fluoro-methyl group are disordered over two sites in a 0.515 (6): 0.485 (6) ratio. The inter-molecular inter-actions in the crystal structure were investigated and qu-anti-fied using Hirshfeld surface analysis.

Novel binuclear copper(II) complexes with sulfanylpyrazole ligands: synthesis, crystal structure, fungicidal, cytostatic, and cytotoxic activity.

New binuclear copper(II) [Cu(II)] tetraligand complexes (six examples) with sulfanylpyrazole ligands were synthesized. Electron spin resonance (ESR) studies have shown that in solution the complexes are transformed to the mononuclear one. Fungicidal properties against Candida albicans were found for the Cu complexes with benzyl and phenyl substituents. An in vitro evaluation of the cytotoxic properties of Cu chelates against HEK293, Jurkat, MCF-7, and THP-1 cells identified the Cu complex with the cyclohexylsulfanyl substituent in the pyrazole core as the lead compound, whereas the Cu complex without a sulfur atom in the pyrazole ligand had virtually no cytotoxic or fungicidal activity. The lead Cu(II) complex was more active than cisplatin. Effect of the S-containing Cu complex on apoptosis and cell cycle distribution has been investigated as well.

Highly energetic N-cyano-substituted CL-20 analogues: challenging the stability limits of polynitro hexaazaisowurtzitanes.

To design high-energy-density materials of a new level, it is necessary to develop methods for the functionalization of energetic scaffolds, which will make it possible to tune their physicochemical and energetic properties. For this reason, we have elaborated an approach for synthesizing a new series of energetic cage compounds with advanced properties by introducing the N-cyano group into the polynitro hexaazaisowurtzitane framework. The structures of the obtained substances were fully characterized with a combination of methods, including multinuclear (1H, 13C{1H}, 14N, and 15N{1H}) NMR and IR spectroscopy, high-resolution mass spectrometry, X-ray diffraction analysis, electron microscopy and quantum chemical calculations. For the resulting compounds, thermal stability and safety tests were carried out, calorimetric and pycnometric measurements were performed, and the energetic potential was determined by high-temperature chemical equilibrium thermodynamic calculations. The new cyano derivatives have an acceptable density (up to 1.92 g cm-3) and a high enthalpy of formation (up to 2 MJ kg-1), which is 2 times that of the benchmark CL-20. The resistance of the target compounds to friction (up to 220 N) is the highest compared to CL-20 and its known analogues. 4,10-Dicyano-2,6,8,12-tetranitro-2,4,6,8,10,12-hexaazaisowurtzitane of the new series is the most thermally stable (a Tdec of 238 °C) among the known energetic polynitro hexaazaisowurtzitanes and is the first derivative of this family to surpass CL-20 in heat resistance. Moreover, the specific impulse for the novel materials showed an improvement of 6.5-13 s over CL-20.

Synthesis, crystal structure and Hirshfeld surface analysis of (2Z,2'E)-2,2'-(3-meth-oxy-3-phenylpropane-1,2-diyl-idene)bis-(hydrazine-1-carbo-thioamide) di-methyl-formamide monosolvate.

The overall mol-ecular configuration of the title compound, C12H16N6OS2·C3H7NO, is stabilized in the solid state by intra-molecular C-H⋯N, C-H⋯O, N-H⋯N and N-H⋯O inter-actions, forming S(5) ring motifs. In the crystal, mol-ecules are linked to each other and solvent di-methyl-formamide mol-ecules by N-H⋯S, N-H⋯O, C-H⋯O and C-H⋯S hydrogen bonds, forming a three dimensional network. The phenyl ring of the title compound is disordered over two sites with an occupancy ratio of 0.57 (4):0.43 (4). A Hirshfeld surface analysis was performed to qu-antify the contributions of the different inter-molecular inter-actions, indicating that the most important contributions to the crystal packing are from H⋯H (38.7%), S⋯H / H⋯S (24.0%), C⋯H / H⋯C (18.5%) and N⋯H / H⋯N (9.8%) inter-actions.

Synthesis, crystal structure and Hirshfeld surface analysis of 3-(4-fluoro-phen-yl)-2-formyl-7-methyl-imidazo[1,2-a]pyridin-1-ium chloride monohydrate.

In the title salt, C15H12FN2O+·Cl-·H2O, the imidazo[1,2-a]pyridin-1-ium ring system of the cation is almostly planar [maximum deviaition = -0.047 (2) Šfor the ring C atom with the attached arene ring] and forms a dihedral angle of 61.81 (6)° with the plane of the fluoro-phenyl ring. In the crystal, water mol-ecules form an R 2 4(8) motif parallel to the (100) plane by bonding with the chloride ions via O-H⋯Cl hydrogen bonds. The cations are connected along the b axis via N-H⋯O hydrogen bonds involving the O atoms of water mol-ecules, and C-H⋯O, C-H⋯Cl and π-π inter-actions [centroid-to-centroid distance = 3.6195 (8) Å] form layers parallel to the (100) plane. Furthermore, these layers are connected via π-π inter-actions [centroid-to-centroid distance = 3.8051 (9) Å] that further consolidate the crystal structure.

Oxygen-Containing Quaternary Phosphonium Salts (oxy-QPSs): Synthesis, Properties, and Cellulose Dissolution.

In the present study, the synthesis of oxygen-containing quaternary phosphonium salts (oxy-QPSs) was described. Within this work, structure-property relationships of oxy-QPSs were estimated by systematic analysis of physical-chemical properties. The influence of the oxygen-containing substituent was examined by comparing the properties of oxy-QPSs in homology series as well as with phosphonium analog-included alkyl side chains. The crystal structure analysis showed that the oxygen introduction influences the conformation of the side chain of the oxy-QPS. It was found that oxy-QPSs, using an aprotic co-solvent, dimethylsulfoxide (DMSO), can dissolve microcrystalline cellulose. The cellulose dissolution in oxy-QPSs appeared to be dependent on the functional group in the cation and anion nature. For the selected conditions, dissolution of up to 5 wt% of cellulose was observed. The antimicrobial activity of oxy-QPSs under study was expected to be low. The biocompatibility of oxy-QPSs with fermentative microbes was tested on non-pathogenic Saccharomyces cerevisiae, Lactobacillus plantarum, and Bacillus subtilis. This reliably allows one to safely address the combined biomass destruction and enzyme hydrolysis processes in one pot.

Crystal structure and Hirshfeld surface analysis of (E)-1-(2,4-di-methyl-furan-3-yl)-3-phenyl-prop-2-en-1-one.

The title compound, C15H14O2, adopts an E configuration about the C=C double bond. The furan ring is inclined to the phenyl ring by 12.03 (9)°. In the crystal, pairs of mol-ecules are linked by C-H⋯O hydrogen bonds, forming dimers with R 2 2(14) ring motifs. The mol-ecules are connected via C-H⋯π inter-actions, forming a three dimensional network. No π-π inter-actions are observed.

Tuning Crystal Packing and Magnetic Properties in a Series of [Dy12] Metallocubanes Based on Azobenzene Derivatives of Salicylic Acid.

A series of four new Dy12 dodecanuclear clusters based on azobenzene derivative ligands of salicylic acid (L1-L4) has been synthesized and characterized in the crystalline phase using X-ray diffraction on single crystal and powder, IR spectroscopy, elemental analysis, and DSC-TGA methods. It was revealed that all obtained clusters exhibit the formation of the similar metallic cluster nodes, as vertex-sharing heterocubanes, obtained from four Dy3+ cations, three bridging hydroxyl groups, and O atoms from the salicylic ligands. The coordination geometry around the Dy(III) centers has been carefully analyzed. Whereas Dy12-L1 and Dy12-L2 with L1 and L2 containing Me and OMe groups in para positions of the phenyl rings, respectively, form similar porous 3D diamond-like molecular networks due to CH-π interactions, for Dy12-L3 with L3 bearing NO2-electron-withdrawing group, the generation of 2D molecular grids assembled by π-π staking is observed, and for Dy12-L4 with L4 bearing phenyl substituent, 3D hexagonal channels have been generated. The complexes Dy12-L1, Dy12-L2, and Dy12-L3 exhibit a zero-field slow magnetic relaxation effect. After UV irradiation of Dy12-L1, a decrease of the magnetic anisotropy energy barrier displaying the possibility of control over magnetic properties by the external stimulus has been observed.

Synthesis of Morpholine-, Piperidine-, and N-Substituted Piperazine-Coupled 2-(Benzimidazol-2-yl)-3-arylquinoxalines as Novel Potent Antitumor Agents.

A novel series of 2-(benzimidazol-2-yl)quinoxalines with three types of pharmacophore groups, namely, piperazine, piperidine, and morpholine moieties, which are part of known antitumor drugs, was designed and synthesized. The compounds have been characterized by NMR and IR spectroscopy, high- and low-resolution mass spectrometry, and X-ray crystallography. 2-(Benzimidazol-2-yl)quinoxalines with N-methylpiperazine substituents showed promising activity against a wide range of cancer lines, without causing hemolysis and showing little cytotoxicity against normal human Wi-38 cells (human fetal lung). A mixture of regioisomers 2-(benzimidazol-2-yl)-3-(4-fluorophenyl)-6(and 7)-(4-methylpiperazin-1-yl)quinoxalines (mri BIQ 13da/14da) showed a highly selective cytotoxic effect against human lung adenocarcinoma (cell line A549) with a half-maximal inhibitory concentration at the level of doxorubicin with a selectivity index of 12. The data obtained by flow cytometry, fluorescence microscopy, and multiparametric fluorescence analysis suggested that the mechanism of the cytotoxic effect of the mri BIQ 13da/14da on A549 cells may be associated with the stopping of the cell cycle in phase S and inhibition of DNA synthesis as well as with the induction of mithochondrial apoptosis. Thus, mri BIQ 13da/14da can be considered as a leading compound deserving further study, optimization, and development as a new anticancer agent.

Triple-bridged helical binuclear copper(i) complexes: Head-to-head and head-to-tail isomerism and the solid-state luminescence.

A family of helical dinuclear copper(i) pyridylphospholane complexes [Cu2L3X]X (X = BF4-, Cl- and Br-) was prepared. The family includes the first examples of this type of complex based on copper(i) chloride and copper(i) bromide. The two isomers typical of this class of compounds, namely head-to-head and head-to-tail complexes, were studied in solution by spectroscopic and optical methods, and in the solid state by X-ray diffraction. Furthermore, the solid-state luminescence of the complexes at different temperatures was studied, and the results were interpreted using quantum-chemical calculations. It was shown that the luminescence of the complexes is attributed to the 3(M + X)LCT transitions.

Cu4I4-cubane clusters based on 10-(aryl)phenoxarsines and their luminescence.

In this work, we present the synthesis, structural and photophysical characterization, and theoretical study of tetranuclear copper(i) cubane-type Cu4I4 clusters 6-10 with different 10-(aryl)phenoxarsine ligands - 10-(p-fluorophenyl)phenoxarsine (1), 10-(p-ethoxyphenyl)phenoxarsine (2), 10-(phenyl)phenoxarsine (3), 10-(m-fluorophenyl)phenoxarsine (4), and 10-(o-methoxyphenyl)phenoxarsine (5), respectively. The structures of 1-5 were confirmed by NMR spectroscopy, mass spectrometry, elemental analysis and for complexes 6, 7, and 10 by single-crystal X-ray diffraction analysis. The UV/Vis absorption and emission properties were studied and rationalized by DFT and time-dependent DFT calculations. In the solid state, under UV irradiation, all complexes exhibit an intense green emission, which was attributed to a cluster-centered triplet state.

Intriguing Near-Infrared Solid-State Luminescence of Binuclear Silver(I) Complexes Based on Pyridylphospholane Scaffolds.

A series of novel charged disilver(I) complexes with pyridyl-containing phospholanes was synthesized. These complexes were characterized using a range of spectroscopic techniques and single-crystal and powder X-ray diffraction. The complexes demonstrate solid-state near-infrared (NIR) luminescence (765-902 nm) that is unique for dinuclear AgI complexes. Combined spectroscopic/quantum chemical analysis suggests that the NIR luminescence of complexes 4-6 in the solid state is mainly due to crystal packing effects.

The Assembly of Unique Hexanuclear Copper(I) Complexes with Effective White Luminescence.

The unique L2Cu6I6 complexes containing two Cu3I3 units have been obtained via reaction of 1,5-diaza-3,7-diphosphacyclooctanes bearing ethylpyridyl substituents at phosphorus atoms with an excess of copper iodide. The structure of one of the complexes was confirmed by X-ray diffraction. It was shown that the complexes can exist in two crystalline phases with different parameters of the unit cell, which were detected by the PXRD data analyses. The solvent-free crystalline phases of the complexes display rare solid-state white emission at room temperature, which is observed due to the presence of two broad bands in the emission spectra with maxima at 464 and 610 nm. Quantum chemical computations show that the high-energy band has 3(M+X)LCT origin, whereas the low-energy band is interpreted as 3CC. The quantum yields of white luminescence of complexes reach 15-20%.

Polystyrenesulfonate-coated nanoparticles with low cytotoxicity for determination of copper(II) via the luminescence of Tb(III) complexes with new calix[4]arene derivatives.

The authors describe new ligands with two 1,3-diketone groups and two heteroaromatic (pyridyl or quinolyl) moieties embedded to the upper and lower rims of dibromo-substituted calix[4]arene scaffold. The ligands bind Tb(III) ions in alkaline DMF solutions to form 1:1 complexes. The strong Tb(III)-centered luminescence (with excitation/emission peaks at 330/545 nm) of the complexes results from efficient ligand-to-metal energy transfer. The complexes were incorporated into polystyrenesulfonate (PSS) colloids by diluting a DMF solution of the complex with aqueous solution of PSS. The luminescence of the colloids is quenched by copper(II), and this was used to develop a method for its fluorometric determination in nanomolar concentrations. The lower limit of detection is 0.88 nM. Quenching is a result of (a) ion exchange which converts the terbium complexes into their copper counterparts, and (b) energy transfer from Tb(III) to Cu(II) complexes. The low cytotoxicity of the colloidal nanoprobe conceivably makes it a promising tool for use in cellular imaging. Graphical abstract New calix[4]arene derivative provide efficient binding sites for Tb(III) and Cu(II) ions. The Tb(III) complexes were embedded to core-shell nanoparticles by solvent-mediated aggregation followed by polystryrenesulfonate deposition. The nanoparticles exhibit luminescence response on copper ions in nanomolar concentration range.