Nanoarhitectonics of Inorganic-Organic Silica-Benzil Composites: Synthesis, Nanocrystal Morphology and Micro-Raman Analysis.

The synthesis of nanosized organic benzil (C6H5CO)2 crystals within the mesoporous SiO2 host matrix was investigated via X-ray diffraction, transmission electron microscopy, Raman spectroscopy, and ab initio lattice dynamics analysis. Combining these methods, we have proved that the main structural properties of benzil nanocrystals embedded into SiO2 host membranes with pore diameters of 6.0, 7.8, 9.4, and 13.0 nm are preserved compared to a bulk benzil crystal. Space confinement has an insignificant impact on the lattice vibrational properties of benzil crystals implanted into the host matrices. The ab initio lattice dynamics calculation of the phonon spectrum in the Brillouin zone center shows the mechanical and dynamical stability of benzil lattice, revealing very low optical frequency of 11 cm-1 at point Γ.

Second harmonic generation on crystalline organic nanoclusters under extreme nanoconfinement in functionalized silica-benzil composites.

We demonstrate a series of organic-inorganic nanocomposite materials combining the mesoporous silica (PS) and benzil (BZL) nanocrystals embedded into its nanochannels (6.0-13.0 nm in diameter) by capillary crystallization. One aims to design novel, efficient nonlinear optical composite materials in which inactive amorphous host PS-matrix provides a tubular scaffold structure, whereas nonlinear optical functionality results from specific properties of the deposited guest BZL-nanocrystals. A considerable contraction of the BZL melt during its crystallization inside the silica nanochannels results in a formation of the texture consisting of (221)- and (003)-oriented BZL nanoclusters (22 nm in length), separated by voids. Specificity of the textural morphology similarly to the spatial confinement significantly influences the nonlinear optical features of composite PS:BZL materials being explored in the second harmonic generation (SHG) experiment. The light polarization anisotropy of the SHG response appears to be considerably reduced at channel diameters larger than 7 nm apparently due to the multiple scattering and depolarization of the light on randomly distributed and crystallographically oriented BZL-nanoclusters. The normalized SHG response decreases nonlinearly by more than one order of magnitude as the channel diameter decreases from 13.0 to 6.0 nm and vanishes when spatial cylindrical confinement approaches the sizes of a few molecular layers suggesting that the embedded BZL clusters indeed are not uniformly crystalline but are characterized by more complex morphology consisting of a disordered SHG-inactive amorphous shell, covering the channel wall, and SHG-active crystalline core. Understanding and controlling of the textural morphology in inorganic-organic nanocrystalline composites as well as its relationships with nonlinear optical properties can lead to the development of novel efficient nonlinear optical materials for the light energy conversion with prospective optoelectronic and photonic applications.

Synthesis, crystal structure and Hirshfeld surface analysis of (4-methyl-phen-yl)[1-(penta-fluoro-phen-yl)-5-(tri-fluoro-meth-yl)-1H-1,2,3-triazol-4-yl]methanone.

The title compound, C17H7F8N3O, was obtained via the reaction of 1-azido-2,3,4,5,6-penta-fluoro-benzene with 4,4,4-tri-fluoro-1-(p-tol-yl)butane-1,3-dione using tri-ethyl-amine as a base catalyst and solvent. The dihedral angles between the penta-fluoro-phenyl (A), triazole (B) and p-tolyl (C) rings are A/B = 62.3 (2), B/C = 43.9 (3) and A/C = 19.1 (3)°. In the crystal, the mol-ecules are linked by C-H⋯F and C-H⋯O hydrogen bonds as well as by aromatic π-π stacking inter-actions into a three-dimensional network. To further analyse the inter-molecular inter-actions, a Hirshfeld surface analysis was performed.

Syntheses and crystal structures of two copper(I)-halide π,σ-coordination compounds based on 2-[(prop-2-en-1-yl)sulfan-yl]pyridine.

The title compounds, di-µ-chlorido-bis-({2-[(η-2,3)-(prop-2-en-1-yl)sulfan-yl]pyridine-κN}copper(I)), [Cu2Cl2(C8H9NS)2], and di-µ-bromido-bis-({2-[(η-2,3)-(prop-2-en-1-yl)sulfan-yl]pyridine-κN}copper(I)), [Cu2Br2(C8H9NS)2], were obtained by alternating-current electrochemical synthesis starting from an ethano-lic solution of 2-[(prop-2-en-1-yl)sulfan-yl]pyridine (Psup) and the copper(II) halide. The isostructural crystals are built up from centrosymmetric [Cu2 Hal 2(Psup)2] dimers, which are formed due to the π,σ-chelating behavior of the organic ligand. In the crystals, the dimers are linked by C-H⋯Hal hydrogen bonds as well as by aromatic π-π stacking inter-actions into a three-dimensional network.

Synthesis, crystal structure and Hirshfeld surface analysis of 5-cyclo-propyl-N-(2-hy-droxy-eth-yl)-1-(4-methyl-phen-yl)-1H-1,2,3-triazole-4-carboxamide.

The title compound, C15H18N4O2, was obtained via a two-step synthesis (Dimroth reaction and amidation) for anti-cancer activity screening and was selected from a 1H-1,2,3-triazole-4-carboxamide library. The cyclo-propyl ring is oriented almost perpendicular to the benzene ring [dihedral angle = 87.9 (1)°], while the dihedral angle between the mean plane of the cyclo-propyl ring and that of the triazole ring is 55.6 (1)°. In the crystal, the mol-ecules are linked by O-H⋯O and C-H⋯N inter-actions into infinite ribbons propagating in the [001] direction, which are inter-connected by weak C-H⋯O inter-actions into layers. The inter-molecular inter-actions were characterized via Hirshfeld surface analysis, which indicated that the largest fingerprint contact percentages are H⋯H (55.5%), N⋯H/H⋯N (15.4%), C⋯H/H⋯C (13.2%) and O⋯H/H⋯O (12.9%).

Synthesis, structure and computational study of 5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine (Pesta) and its heterometallic π,σ-complex [Cu2FeCl2(Pesta)4][FeCl4].

Copper(I) π-coordination compounds with allyl derivatives of azoles are an interesting subject of current research, but CuI π-complexes with other transition-metal ions incorporated in the structure have been virtually uninvestigated. The present work is directed toward the synthesis and structural characterization of the novel heterometallic CuI/FeII π-complex di-µ2-chlorido-1:2κ2Cl;2:3κ2Cl-tetrakis[µ2-5-(prop-2-en-1-ylsulfanyl)-1,3,4-thiadiazol-2-amine]-1:2κ2N4:N3;1(η2),κN4:2κN3;2:3κ2N3:N4;2κN3:3(η2),κN4-dicopper(I)iron(II) tetrachloridoferrate(II), [Cu2FeCl2(C5H7N3S2)4][FeCl4] (1). The structure of the 5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine (Pesta, C5H7N3S2) ligand is also presented. The cationic substructure in 1 consists of one FeII and two CuI ions bridged by two chloride ions along with two σ,σ- and two π,σ-coordinated ligands, whereas the anionic part is built of isolated tetrahedral [FeCl4]2- ions. π-Coordination of the Pesta allyl group to the CuI ions prevents agglomeration of the inorganic Cu-Cl-Fe-Cl-Cu part into infinate chains. An energy framework computational analysis was performed for Pesta.

Synthesis, crystal structure and Hirshfeld surface analysis of N-(4-chloro-phen-yl)-5-cyclo-propyl-1-(4-meth-oxy-phen-yl)-1H-1,2,3-triazole-4-carboxamide.

The title compound, C19H17ClN4O2, was obtained via a two-step synthesis involving the enol-mediated click Dimroth reaction of 4-azido-anisole with methyl 3-cyclo-propyl-3-oxo-propano-ate leading to the 5-cyclo-propyl-1-(4-meth-oxy-phen-yl)-1H-1,2,3-triazole-4-carb-oxy-lic acid and subsequent acid amidation with 4-chloro-aniline by 1,1'-carbonyl-diimidazole (CDI). It crystallizes in space group P21/n, with one mol-ecule in the asymmetric unit. In the extended structure, two mol-ecules arranged in a near coplanar fashion relative to the triazole ring planes are inter-connected by N-H⋯N and C-H⋯N hydrogen bonds into a homodimer. The formation of dimers is a consequence of the above inter-action and the edge-to-face stacking of aromatic rings, which are turned by 58.0 (3)° relative to each other. The dimers are linked by C-H⋯O inter-actions into ribbons. DFT calculations demonstrate that the frontier mol-ecular orbitals are well separated in energy and the HOMO is largely localized on the 4-chloro-phenyl amide motif while the LUMO is associated with aryl-triazole grouping. A Hirshfeld surface analysis was performed to further analyse the inter-molecular inter-actions.

Cu(I) Arylsulfonate D€-Complexes with 3-Allyl-2-thiohydantoin: The Role of the Weak Interactions in Structural Organization.

The present work is directed toward preparation and structural characterization of two novel Cu(I) arylsulfonate ?-complexes with 3-allyl-2-thiohydantoin, namely [Cu2(Hath)4](C6H5SO3)2 (1) and [Cu2(Hath)4](p-CH3C6H4SO3)2·2H2O (2) (Hath = 3-allyl-2-thiohydantoin), obtained by the means of alternating current electrochemical synthesis and studied with X-ray diffraction method. In both structures, the inner coordination sphere is represented by the cationic dimer [Cu2(Hath)4]2+ with one crystallographically independent copper(I) atom which has a trigonal pyramidal coordination environment formed by three Hath thiogroup S atoms and double C=C bond of its allyl group. [Cu2(Hath)4]2+ fragments in both coordination compounds are very similar, despite some divergences such as a big difference in Cu?S distance to the apical S atom (3.0374(8) ? in 1 and 2.7205(9) ? in 2). This difference was explained by the impact of the system of weak interactions, which are quite different.

Crystal structure, Hirshfeld surface analysis and computational studies of 5-[(prop-2-en-1-yl)sulfan-yl]-1-[2-(tri-fluoro-meth-yl)phen-yl]-1H-tetra-zole.

The title compound, C11H9F3N4S, was synthesized from 2-(tri-fluoro-meth-yl)aniline by a multi-step reaction. It crystallizes in the non-centrosymmetric space group Pna21, with one mol-ecule in the asymmetric unit, and is constructed from a pair of aromatic rings [2-(tri-fluoro-meth-yl)phenyl and tetra-zole], which are twisted by 76.8 (1)° relative to each other because of significant steric hindrance of the tri-fluoro-methyl group at the ortho position of the benzene ring. In the crystal, very weak C-H⋯N and C-H⋯F hydrogen bonds and aromatic π-π stacking inter-actions link the mol-ecules into a three-dimensional network. To further analyse the inter-molecular inter-actions, a Hirshfeld surface analysis, as well as inter-action energy calculations, were performed.

Ligand-forced dimerization of copper(I)-olefin complexes bearing a 1,3,4-thiadiazole core.

As an important class of heterocyclic compounds, 1,3,4-thiadiazoles have a broad range of potential applications in medicine, agriculture and materials chemistry, and were found to be excellent precursors for the crystal engineering of organometallic materials. The coordinating behaviour of allyl derivatives of 1,3,4-thiadiazoles with respect to transition metal ions has been little studied. Five new crystalline copper(I) π-complexes have been obtained by means of an alternating current electrochemical technique and have been characterized by single-crystal X-ray diffraction and IR spectroscopy. The compounds are bis[µ-5-methyl-N-(prop-2-en-1-yl)-1,3,4-thiadiazol-2-amine]bis[nitratocopper(I)], [Cu2(NO3)2(C6H9N3S)2], (1), bis[µ-5-methyl-N-(prop-2-en-1-yl)-1,3,4-thiadiazol-2-amine]bis[(tetrafluoroborato)copper(I)], [Cu2(BF4)2(C6H9N3S)2], (2), µ-aqua-bis{µ-5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine}bis[nitratocopper(I)], [Cu2(NO3)2(C5H7N3S2)2(H2O)], (3), µ-aqua-(hexafluorosilicato)bis{µ-5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine}dicopper(I)-acetonitrile-water (2/1/4), [Cu2(SiF6)(C5H7N3S2)2(H2O)]·0.5CH3CN·2H2O, (4), and µ-benzenesulfonato-bis{µ-5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine}dicopper(I) benzenesulfonate-methanol-water (1/1/1), [Cu2(C6H5O3S)(C5H7N3S2)2](C6H5O3S)·CH3OH·H2O, (5). The structure of the ligand 5-methyl-N-(prop-2-en-1-yl)-1,3,4-thiadiazol-2-amine (Mepeta), C6H9N3S, was also structurally characterized. Both Mepeta and 5-[(prop-2-en-1-yl)sulfanyl]-1,3,4-thiadiazol-2-amine (Pesta) (denoted L) reveal a strong tendency to form dimeric {Cu2L2}2+ fragments, being attached to the metal atom in a chelating-bridging mode via two thiadiazole N atoms and an allylic C=C bond. Flexibility of the {Cu2(Pesta)2}2+ unit allows the CuI atom site to be split into two positions with different metal-coordination environments, thus enabling the competitive participation of different molecules in bonding to the metal centre. The Pesta ligand in (4) allows the CuI atom to vary between water O-atom and hexafluorosilicate F-atom coordination, resulting in the rare case of a direct CuI...FSiF52- interaction. Extensive three-dimensional hydrogen-bonding patterns are formed in the reported crystal structures. Complex (5) should be considered as the first known example of a CuI(C6H5SO3) coordination compound. To determine the hydrogen-bond interactions in the structures of (1) and (2), a Hirshfeld surface analysis has been performed.

Two Related Copper(I) π-Complexes Based on 2-Allyl-5-(2-pyridyl)-2H-tetrazole Ligand: Synthesis and Structure of [Cu(2-apyt)NO3] and [Cu(2-apyt)(H2O)](BF4) Compounds.

By means of the alternating current electrochemical technique two new π-compounds [Cu(2-apyt)NO3] (1) and [Cu(2-apyt)(H2O)](BF4) (2) have been obtained starting from the mixture of 1-allyl-5-(2-pyridyl)-2H-tetrazole (1-apyt), 2-allyl-5-(2-pyridyl)-2H-tetrazole (2-apyt) and corresponding copper(II) salts, and have been structurally studied. Selective complexation towards 2-allyl- isomer results in a formation of 2-apyt complexes. Copper(I) ion in both 1 and 2 complexes coordinates the allylic C=C bond, one pyridyl and one tetrazole N atoms. In both structures Cu+ center adopts distorted tetrahedral surrounding which additionally includes oxygen of NO3(-) in 1 and H2O moiety in 2. Structure 1 is built from [Cu(2-apyt)NO3]2 dimeric fragments. Contrary, participation of H2O in the metal coordination in 2 leads to the infinite {[Cu(2-apyt)(H2O)]+}n chain construction. To analyze interactions between the particles in 1 and 2 Hirshfeld surface analysis was performed.