2-Cyano-2-iso-nitro-soacetamide-3,4-di-methylpyrazole (1/1): a co-crystal of two mol-ecules with agrochemical activities.

In the structure of the title co-crystal, C3H3N3O2·C5H8N2, the components are linked by a set of directional O-H⋯N, N-H⋯O, N-H⋯N and C-H⋯O hydrogen bonds to yield a two-dimensional mono-periodic arrangement. The structure propagates in the third dimension by extensive π-π stacking inter-actions of nearly parallel mol-ecules of the two components, following an alternating sequence. The primary structure-defining inter-action is very strong oxime-OH donor to pyrazole-N acceptor hydrogen bond [O⋯N = 2.587 (2) Å], while the significance of weaker hydrogen bonds and π-π stacking inter-actions is comparable. The distinct structural roles of different kinds of inter-actions agree with the results of a Hirshfeld surface analysis and calculated inter-action energies. The title compound provides insights into co-crystals of active agrochemical mol-ecules and features the rational integration in one structure of a fungicide, C3H3N3O2, and a second active component, C5H8N2, known for alleviation the toxic effects of fungicides on plants. The material appears to be well suited for practical uses, being non-volatile, air-stable, water-soluble, but neither hygroscopic nor efflorescent.

CONFLICTS OF INTEREST IN THE HEALTHCARE SECTOR: LEGAL ASPECTS.

OBJECTIVE: The aim: To study the features of legal regulation of preventing conflicts of interest in the healthcare field in foreign countries in order to propose improvements to national legislation. PATIENTS AND METHODS: Materials and methods: The methodological basis of the article is a set of methods and techniques of scientific knowledge. Methods of theoretical analysis, system-analytical, comparative-legal methods provided us with the opportunity to characterize the features of the legal regulation of preventing conflicts of interest in the area under study. RESULTS: Results: The common features of preventing conflicts of interest in the healthcare field in foreign countries are: (1) a combination of mandatory, recommendatory, ethical and legal norms that define a number of requirements, restrictions and prohibitions in this area; (2) different levels of legal regulation of conflicts of interest (international, national, regional, local); (3) two approaches to determining the content of conflict of interest: general (the conflict is defined the same for all cases) and differentiated (the conflict of interest is determined by each area, taking into account its specifics). The debatable and problematic issues of conflict prevention in the national healthcare system are analyzed, and amendments to the medical legislation are proposed. CONCLUSION: Conclusions: Prevention of conflict of interest in the healthcare field should be considered as a specific group of public legal relations and an independent subject of legal regulation arising from the norms of the legislation of most foreign countries.

catena-Poly[[bis-(di-aqua-lithium)]-µ4-3,3',5,5'-tetra-nitro-4,4'-bi-pyrazole-1,1'-diido]: a new moisture-insensitive alkali-metal energetic salt with a well-defined network structure.

In the structure of the title salt, [Li2(C6N8O8)(H2O)4]n, the 3,3',5,5'-tetra-nitro-4,4'-bi-pyrazole-1,1'-diide dianion [{TNBPz}2-] is situated across the twofold axis. The distorted coordination octa-hedra around Li+ involve four short bonds with two pyrazolate N atoms and two aqua ligands [Li-N(O) = 1.999 (3)-2.090 (2) Å] and two longer contacts with nitro-O atoms [2.550 (2), 2.636 (2) Å]. When combined with µ4-{TNBPz}2-, this generates a mono-periodic polymeric structure incorporating discrete centrosymmeric [(H2O)2Li-(di-nitro-pyrazolato)2-Li(H2O)2] units. The three-dimensional stack of mutually orthogonal coordination chains is reminiscent of a Lincoln log pattern. It is influenced by conventional hydrogen bonding [O⋯O = 2.8555 (17)-3.0010 (15) Å] and multiple lone pair-π hole inter-actions of the nitro groups [N⋯O = 3.0349 (15) and 3.0887 (15) Å]. The Hirshfeld surface and two-dimensional fingerprint plots also support the significance of non-covalent bonding. Coordinative saturation and a favorable geometry at the Li+ ions, dense packing of the polymeric subconnectivities and particularly extensive inter-anion inter-actions may be involved in the stabilization of the structure. The title salt is a rare example of an energetic Li nitro-azolate, which nicely crystallizes from aqueous solution and is neither hygroscopic nor efflorescent. The TG/DTA data reveal total dehydration in the range of 330-430 K and stability of the anhydrous material up to 633-653 K.

Gradual evolution of hydrogen-bonding patterns with the carbamoylcyanonitrosomethanide anion in a series of aliphatic diammonium salts.

Developing the structures of organic materials that rely on the hydrogen bonding of multifunctional substrates is often complicated due to a competition between various possible motifs. In this context, the illustrative case of the carbamoylcyanonitrosomethanide anion, [ONC(CN)-C(O)NH2]-, suggests sufficient control over the crystal lattice with a set of supramolecular synthons, which are specific to all the present nitroso, carbamoyl and cyano groups. The structures of the carbamoylcyanonitrosomethanide salts of ethane-1,2-diammonium, C2H10N22+·2C3H2N3O2-, (1), piperazine-1,4-diium, C4H12N22+·2C3H2N3O2-, (2), butane-1,4-diammonium, C4H14N22+·2C3H2N3O2-, (3), and hexane-1,6-diammonium, C6H18N22+·2C3H2N3O2-, (4), reveal two- and three-dimensional hydrogen-bonded frameworks governed by a set of site-selective interactions. The strongest N-H...O hydrogen bonds [N...O = 2.6842 (17)-2.8718 (17) Å, mean 2.776 (2) Å] are associated with the polarized ammonium N-H donors and nitroso O-atom acceptors, which sustain invariant motifs in the form of nitroso/ammonium dimers. Subtle structural changes within this series of compounds concern the rupture of some weaker interactions, i.e. mutual hydrogen bonds of the carbamoyl groups in (1)-(3) [N...O = 2.910 (2)-2.9909 (18) Å; mean 2.950 (2) Å] and carbamoyl/nitrile hydrogen bonds in (1), (2) and (4) [N...N = 2.936 (2)-3.003 (3) Å, mean 2.977 (2) Å], providing a gradual evolution of the hydrogen-bonding pattern. A hierarchy of the synthons involving three different groups could be applicable to supramolecular synthesis with polyfunctional methanide species, suggesting also a degree of control over layered and interpenetrated hydrogen-bonded networks.

Crystal structure of tetra-kis-(µ-4-benzyl-4H-1,2,4-triazole-κ2 N 1:N 2)tetra-fluoridodi-µ2-oxido-dioxidodisilver(I)divanadium(V).

The crystal structure of the title compound, [Ag2(VO2F2)2(C9H9N3)4], is presented. The mol-ecular complex is based on the heterobimetallic AgI-VV fragment {AgI 2(VVO2F2)2(tr)4} supported by four 1,2,4-triazole ligands [4-benzyl-(4H-1,2,4-triazol-4-yl)]. The triazole functional group demonstrates homo- and heterometallic connectivity (Ag-Ag and Ag-V) of the metal centers through the [-NN-] double and single bridges, respectively. The vanadium atom possesses a distorted trigonal-bipyramidal coordination environment [VO2F2N] with the Reedijk structural parameter τ = 0.59. In the crystal, C-H⋯O and C-H⋯F hydrogen bonds as well as C-H⋯π contacts are observed involving the organic ligands and the vanadium oxofluoride anions. A Hirshfeld surface analysis of the hydrogen-bonding inter-actions is also described.

Hydrogen-bonding landscape of the carbamoyl-cyano-nitro-somethanide anion in the crystal structure of its ammonium salt.

The structure of the title salt, ammonium carbamoyl-cyano-nitro-somethanide, NH4 +·C3H2N3O2 -, features the co-existence of different hydrogen-bonding patterns, which are specific to each of the three functional groups (nitroso, carbamoyl and cyano) of the methanide anion. The nitroso O-atoms accept as many as three N-H⋯O bonds from the ammonium cations [N⋯O = 2.688 (3)-3.000 (3) Å] to form chains of fused rhombs [(NH4)(O)2]. The most prominent bonds of the carbamoyl groups are mutual and they yield 21 helices [N⋯O = 2.903 (2) Å], whereas the cyano N-atoms accept hydrogen bonds from sterically less accessible carbamoyl H-atoms [N⋯N = 3.004 (3) Å]. Two weaker NH4 +⋯O=C bonds [N⋯O = 3.021 (2), 3.017 (2) Å] complete the hydrogen-bonded environment of the carbamoyl groups. A Hirshfeld surface analysis indicates that the most important inter-actions are overwhelmingly O⋯H/H⋯O and N⋯H/H⋯N, in total accounting for 64.1% of the contacts for the individual anions. The relatively simple scheme of these inter-actions allows the delineation of the supra-molecular synthons, which may be applicable to crystal engineering of hydrogen-bonded solids containing polyfunctional methanide anions.

Tris[tri-phenyl-anti-mony(V)]hexa(µ-oxido)-tellurium(VI): a mol-ecular complex with six Te-O-Sb bridges.

In the structure of the title compound [systematic name hexa-µ-oxido-1:2κ4 O:O;1:3κ4 O:O;1:4κ4 O:O-nona-phenyl-2κ3 C,3κ3 C,4κ3 C-tri-anti-mony(V)tel-lur-ium(VI)], [Sb3Te(C6H5)9O6], the hexa-oxidotellurate(VI) ion is coordinated to three SbV ions via pairs of cis-positioned O atoms to form a discrete mol-ecular unit. The TeVI and SbV central ions exhibit distorted octa-hedral [TeO6] and distorted trigonal-bipyramidal [SbC3O2] coordination geometries, respectively. The linking of these polyhedra, by sharing the dioxide edges, results in the Te-based octa-hedron having a mer-configuration. The packing of the mol-ecules is dominated by C-H⋯O hydrogen bonding and weak dispersion forces, with a minor contribution from C-H⋯π bonds and π-π stacking inter-actions. According to the Hirshfeld surface analysis, the contributions of the H⋯H, H⋯C/C⋯H and H⋯O/O⋯H contacts are 58.0, 32.6 and 7.8%, respectively. The title structure provides a model for the bonding of triorgano-anti-mony dications to octa-hedral oxoanions, and the observed doubly bridged motifs, Te(µ-O)2Sb, may find application in the functionalization of polyoxometalate species.

Ionothermal Synthesis of Uranyl Vanadate Nanoshell Heteropolyoxometalates.

Two uranyl vanadate heteropolyoxometalates (h-POMs) have been synthesized by ionothermal methods using the ionic liquid 1-ethyl-3-methylimidazolium diethyl phosphate (EMIm-Et2PO4). The hybrid actinide-transition metal shell structures have cores of (UO2)8(V6O22) and (UO2)6(V3O12), which we designate as {U8V6} and {U6V3}, respectively. The diethyl phosphate anions of the ionic liquids in some cases terminate the core structures to form actinyl oxide clusters, and in other cases the diethyl phosphate oxyanions link these cluster cores into extended structures. Three compounds exist for the {U8V6} cluster core: {U8V6}-monomer, {U8V6}-dimer, and {U8V6}-chain. Tungsten atoms can partially substitute for vanadium in the {U6V3} cluster, which results in a chain-based structure designated as {U6V3}-W. Each of these compounds contains charge-balancing EMIm cations from the ionic liquid. These compounds were characterized crystallographically, spectroscopically, and by mass spectrometry.

Crystal structure and Hirshfeld surface analysis of 4,4'-(propane-1,3-diyl)bis(4H-1,2,4-triazol-1-ium) penta-fluorido-oxidovanadate(V).

In the structure of the title salt, (C7H12N6)[VOF5], second-order Jahn-Teller distortion of the coordination octa-hedra around V ions is reflected by coexistence of short V-O bonds [1.5767 (12) Å] and trans-positioned long V-F bonds [2.0981 (9) Å], with four equatorial V-F distances being inter-mediate in magnitude [1.7977 (9)-1.8913 (9) Å]. Hydrogen bonding of the anions is restricted to F-atom acceptors only, with particularly strong N-H⋯F inter-actions [N⋯F = 2.5072 (15) Å] established by axial and cis-positioned equatorial F atoms. Hirshfeld surface analysis indicates that the most important inter-actions are overwhelmingly H⋯F/F⋯H, accounting for 74.4 and 36.8% of the contacts for the individual anions and cations, respectively. Weak CH⋯F and CH⋯N bonds are essential for generation of three-dimensional structure.

Bulk polarity of 3,5,7-trinitro-1-azaadamantane mediated by asymmetric NO2(lone pair)...NO2(π-hole) supramolecular bonding.

Molecular crystals exhibiting polar symmetry are important paradigms for developing new electrooptical materials. Though accessing bulk polarity still presents a significant challenge, in some cases it may be rationalized as being associated with the specific molecular shapes and symmetries and subtle features of supramolecular interactions. In the crystal structure of 3,5,7-trinitro-1-azaadamantane, C9H12N4O6, the polar symmetry of the molecular arrangement is a result of complementary prerequisites, namely the C3v symmetry of the molecules is suited to the generation of polar stacks and the inherent asymmetry of the principal supramolecular bonding, as is provided by NO2(lone pair)...NO2(π-hole) interactions. These bonds arrange the molecules into a trigonal network. In spite of the apparent simplicity, the structure comprises three unique molecules (Z' = 1/3 + 1/3 + 1/3), two of which are donors and acceptors of three N...O interactions and the third being primarily important for weak C-H...O hydrogen bonding. These distinct structural roles agree with the results of Hirshfeld surface analysis. A set of weak C-H...O and C-H...N hydrogen bonds yields three kinds of stacks. The orientation of the stacks is identical and therefore the polarity of each molecule contributes additively to the net dipole moment of the crystal. This suggests a special potential of asymmetric NO2(lone pair)...NO2(π-hole) interactions for the supramolecular synthesis of acentric materials.

A Molybdenum Trioxide Hybrid Decorated by 3-(1,2,4-Triazol-4-yl)adamantane-1-carboxylic Acid: A Promising Reaction-Induced Self-Separating (RISS) Catalyst.

3-(1,2,4-Triazol-4-yl)adamantane-1-carboxylic acid (tradcH), a heterobifunctional organic ligand in which carboxylic acid and 1,2,4-triazole groups are united through a rigid 1,3-adamantanediyl spacer, was employed for the synthesis of a MoVI oxide organic hybrid. The ligand crystallized from water as tradcH·H2O (1), possessing a two-dimensional hydrogen-bonding network, and from ethanol as a cyclic molecular solvate with the composition (tradcH)3·2EtOH (2). Treatment of tradcH with MoO3 under hydrothermal conditions afforded a new Mo trioxide hybrid, [MoO3(tradcH)]·H2O (3), which was structurally characterized. In 3, the molybdenum atoms form a polymeric zigzag chain of {µ2-O-MoO2}n which is supported by double triazole bridges, while the carboxylic acid termini are left uncoordinated. The coordination environment of the Mo centers appears as distorted cis-{MoN2O4} octahedra. The hybrid exhibits high thermal stability (up to 270 °C) and was employed for a relatively broad scope of catalytic oxidation reactions in the liquid phase. Its catalytic behavior may be compared to a reversible mutation, featuring the best sides of homogeneous and heterogeneous catalysis. The original solid material converts into soluble active species, and the latter revert to the original material upon completion of the catalytic reaction, precipitating and allowing straightforward catalyst separation/reuse (like a heterogeneous catalyst). This catalyst was explored for a chemical reaction scope covering sulfoxidation, oxidative alcohol dehydrogenation, aldehyde oxidation, and olefin epoxidation, using hydrogen peroxide as an eco-friendly oxidant that gives water as a coproduct.

Crystal structure of tetra-kis-[µ-3-carboxy-1-(1,2,4-triazol-4-yl)adamantane-κ2 N 1:N 2]tetra-fluoridodi-µ2-oxido-dioxidodisilver(I)divanadium(V) tetra-hydrate.

The crystal structure of the title mol-ecular complex, [Ag2{VO2F2}2(C13H17N3O2)4]·4H2O, supported by the heterofunctional ligand tr-ad-COOH [1-(1,2,4-triazol-4-yl)-3-carb-oxy-adamantane] is reported. Four 1,2,4-triazole groups of the ligand link two AgI atoms, as well as AgI and VV centres, forming the heterobimetallic coordination cluster {AgI 2(VVO2F2)2(tr)4}. VV exists as a vanadium oxofluoride anion and possesses a distorted trigonal-bipyramidal coordination environment [VO2F2N]. A carb-oxy-lic acid functional group of the ligand stays in a neutral form and is involved in hydrogen bonding with solvent water mol-ecules and VO2F2 - ions of adjacent mol-ecules. The extended hydrogen-bonding network is responsible for the crystal packing in the structure.

Crystal structure of poly[[[µ4-3-(1,2,4-triazol-4-yl)adamantane-1-carboxyl-ato-κ5 N 1:N 2:O 1:O 1,O 1']silver(I)] dihydrate].

The heterobifunctional organic ligand, 3-(1,2,4-triazol-4-yl)adamantane-1-carboxyl-ate (tr-ad-COO- ), was employed for the synthesis of the title silver(I) coordination polymer, {[Ag(C13H16N3O2)]·2H2O} n , crystallizing in the rare ortho-rhom-bic C2221 space group. Alternation of the double µ2-1,2,4-triazole and µ2-η2:η1-COO- (chelating, bridging mode) bridges between AgI cations supports the formation of sinusoidal coordination chains. The AgI centers possess a distorted {N2O3} square-pyramidal arrangement with τ5 = 0.30. The angular organic linkers connect the chains into a tetra-gonal framework with small channels along the c-axis direction occupied by water mol-ecules of crystallization, which are inter-linked via O-H⋯O hydrogen bonds with carboxyl-ate groups, leading to right- and left-handed helical dispositions.

Disease as interference for judge's profession.

OBJECTIVE: Introduction: The judge's professional activity determines certain requirements for the health status of the person applying for this position or already performing his professional duties. Due to the specificity of professional activity, it could be cases of diseases that make it's impossible to perform professional functions effectively. It raises the question of the fairness of the dismissal procedure precisely for the health status that would exclude discrimination based on disability. The aim: The purpose of the scientific article is to summarize the leading experience of European countries on the protection and prevention of occupational illnesses of judges in order to substantiate specific proposals for the creation of an optimal procedure for dismissing a judge due to health status. PATIENTS AND METHODS: Materials and methods: The subject under discussion has been considered based on the relevant sources (scientific publications, legal acts, decisions of judicial and quasijudicial institutions), using the method of content analysis, comparative and contrastive, analytical and biblio-semantic methods. CONCLUSION: Conclusions: An analysis of European practice, including judgments on appealing against violations of the right to work due to unlawful dismissal based on health status allowed us to formulate key elements of a fair procedure for dismissing a judge due to illness, which makes it impossible to perform professional functions. A vision on the list of diseases that may be interference to effective judicial activity is developed by the authors. It is substantiated that such list of diseases should be a legal filter to judges employment and dismission. Regular medical examination and prevention of the development of occupational illnesses of a judge should become an integral part of the court's labor protection system. In the event of an accident related to performing professional functions, the judge is entitled to compensation.

On the Border between Low-Nuclearity and One-Dimensional Solids: A Unique Interplay of 1,2,4-Triazolyl-Based {CuII5(OH)2} Clusters and MoVI-Oxide Matrix.

A pentanuclear CuII5-hydroxo cluster possessing an unusual linear-shaped configuration was formed and crystallized under hydrothermal conditions as a result of the unique cooperation of bridging 1,2,4-triazole ligand ( trans-1,4-cyclohexanediyl-4,4'-bi(1,2,4-triazole) ( tr2 cy)), MoVI-oxide, and CuSO4. This structural motif can be rationalized by assuming in situ generation of {Cu2Mo6O22}4- anions, which represent heteroleptic derivatives of γ-type [Mo8O26]4- further interlinked by [Cu3(OH)2]4+ cations through [ N- N] bridges. The framework structure of the resulting compound [Cu5(OH)2( tr2 cy)2Mo6O22]·6H2O (1) is thus built up from neutral heterometallic {Cu5(OH)2Mo6O22} n layers pillared with tetradentate tr2 cy. Quantum-chemical calculations demonstrate that the exclusive site of the parent γ-[Mo8O26]4- cluster into which CuII inserts corresponds with the site that has the lowest defect ("MoO2 vacancy") formation energy, demonstrating how the local metal-polyoxomolybdate chemistry can express itself in the final crystal structure. Magnetic susceptibility measurements of 1 show strong antiferromagnetic coupling within the Cu5 chain with exchange parameters J1 = -500(40) K (-348(28) cm-1), J2 = -350(10) K (-243(7) cm-1) and g = 2.32(2), χ2 = 6.5 × 10-4. Periodic quantum-chemical calculations reproduce the antiferromagnetic character of 1 and connect it with an effective ligand-mediated spin coupling mechanism that comes about from the favorable structural arrangement between the Cu centers and the OH-, O2-, and tr2 cy bridging ligands.

Importance of Considering the Middle Capillary Plexus on OCT Angiography in Diabetic Retinopathy.

Purpose: To quantify microvasculature changes in the superficial (SCP), middle (MCP), and deep capillary plexuses (DCP) in diabetic retinopathy (DR). Methods: Retrospective cross-sectional study at a tertiary academic referral center, in which 26 controls (44 eyes), 27 diabetic subjects without retinopathy (44 eyes), 32 subjects with nonproliferative retinopathy (52 eyes), and 27 subjects with proliferative retinopathy (40 eyes) were imaged with optical coherence tomography angiography (OCTA). Outcome measures included parafoveal vessel density (VD), percentage area of nonperfusion (PAN), and adjusted flow index (AFI) at the different plexuses. Results: MCP VD and MCP AFI decreased with worsening DR, while PAN increased, mirroring changes within the DCP. The fitted regression line for MCP and DCP AFI were significantly different than the SCP, while DCP PAN differed from SCP PAN with disease progression. Higher SCP AFI and PAN were different in eyes with diabetes without retinopathy compared with controls. Unexpectedly, sex was found to independently influence MCP VD and AFI with worsening disease. Conclusions: OCTA parameters in the MCP and DCP displayed parallel changes with DR progression, different from the SCP, emphasizing the importance of physiologic considerations in the retinal capillaries. Thus, segmentation protocols that include the MCP within the SCP may be confounded. A difference in DCP PAN with worsening DR was unmasked relative to a prior study that included the MCP with SCP. We confirm that SCP AFI and PAN may serve as early indicators of microvascular changes in DR and identify an interaction between sex and the MCP deserving further study.

Porous Uranium Diphosphonate Frameworks with Trinuclear Units Templated by Organic Ammonium Hydrolyzed from Amine Solvents.

By varying solvent systems, the solvothermal treatment of uranyl nitrate and methylenediphosphonic acid (H4PCP) afforded three new porous uranyl-organic frameworks (UOFs). All were structurally characterized by single-crystal X-ray diffraction and formulated as (Et2NH2)2[(UO2)3(PCP)2](H2O)2.5 (1), (MeNH3)(H3O)[(UO2)3(PCP)2(H2O)3] (2), and [Na(H2O)4](H3O)[(UO2)3(PCP)2(H2O)2](H2O)5 (3). These compounds crystallize with three-dimensional anionic frameworks containing U(VI) and distinct cationic species due to in situ solvent hydrolysis. The solvent systems diethylformamide (DEF), N-methyl-2-pyrrolindone (NMP), and the additive sodium vanadate (Na3VO4) significantly impact the resultant structures, affording diethyl ammonium, methyl ammonium, and sodium cations captured in channels of the anionic frameworks of 1-3. In 1, a trinuclear U3O18 unit formed by three uranyl polyhedra that share edges is connected into a three-dimensional framework. Compound 2 has a three-dimensional framework formed from a uranyl-methylenediphosphonate layer that is pillared by UO7 pentagonal bipyramids. With the inclusion of sodium cations, 3 is a porous framework containing UO7 pentagonal bipyramids within a layer, with sodium cations and UO6 square bipyramids linking the adjacent layers. Compounds 1-3 feature the uranyl/ligand ratio of 3:2, but present diverse structural building units ranging from edge-shared trinuclear to heteronuclear assemblies. The compounds have been characterized by infrared (IR), Raman, and UV-vis spectroscopies, X-ray diffraction, and thermogravimetric analysis.

Exploration of a Variety of Copper Molybdate Coordination Hybrids Based on a Flexible Bis(1,2,4-triazole) Ligand: A Look through the Composition-Space Diagram.

We investigated the coordination ability of the bis(1,2,4-triazolyl) module, tr2pr = 1,3-bis(1,2,4-triazol-4-yl)propane, toward the engineering of solid-state structures of copper polyoxomolybdates utilizing a composition space diagram approach. Different binding modes of the ligand including [N-N]-bridging and N-terminal coordination and the existence of favorable conformation forms (anti/anti, gauche/anti, and gauche/gauche) resulted in varieties of mixed metal CuI/MoVI and CuII/MoVI coordination polymers prepared under hydrothermal conditions. The composition space analysis employed was aimed at both the development of new coordination solids and their crystallization fields through systematic changes of the reagent ratios [copper(II) and molybdenum(VI) oxide precursors and the tr2pr ligand]. Nine coordination compounds were synthesized and structurally characterized. The diverse coordination architectures of the compounds are composed of cationic fragments such as [CuII3(µ2-OH)2(µ2-tr)2]4+, [CuII3(µ2-tr)6]6+, [CuII2(µ2-tr)3]4+, etc., connected to polymeric arrays by anionic species (molybdate MoO42-, isomeric α-, δ-, and ß-octamolybdates {Mo8O26}4- or {Mo8O28H2}6-). The inorganic copper(I,II)/molybdenum(VI) oxide matrix itself forms discrete or low-dimensional subtopological motifs (0D, 1D, or 2D), while the organic spacers interconnect them into higher-dimensional networks. The 3D coordination hybrids show moderate thermal stability up to 230-250 °C, while for the 2D compounds, the stability of the framework is distinctly lower (∼190 °C). The magnetic properties of the most representative samples were investigated. The magnetic interactions were rationalized in terms of analyzing the planes of the magnetic orbitals.

Triazolyl, Imidazolyl, and Carboxylic Acid Moieties in the Design of Molybdenum Trioxide Hybrids: Photophysical and Catalytic Behavior.

Three organic ligands bearing 1,2,4-triazolyl donor moieties, (S)-4-(1-phenylpropyl)-1,2,4-triazole (trethbz), 4-(1,2,4-triazol-4-yl)benzoic acid (trPhCO2H), and 3-(1H-imidazol-4-yl)-2-(1,2,4-triazol-4-yl)propionic acid (trhis), were prepared to evaluate their coordination behavior in the development of molybdenum(VI) oxide organic hybrids. Four compounds, [Mo2O6(trethbz)2]·H2O (1), [Mo4O12(trPhCO2H)2]·0.5H2O (2a), [Mo4O12(trPhCO2H)2]·H2O (2b), and [Mo8O25(trhis)2(trhisH)2]·2H2O (3), were synthesized and characterized. The monofunctional tr-ligand resulted in the formation of a zigzag chain [Mo2O6(trethbz)2] built up from cis-{MoO4N2} octahedra united through common µ2-O vertices. Employing the heterodonor ligand with tr/-CO2H functions afforded either layer or ribbon structures of corner- or edge-sharing {MoO5N} polyhedra (2a or 2b) stapled by tr-links in axial positions, whereas -CO2H groups remained uncoordinated. The presence of the im-heterocycle as an extra function in trhis facilitated formation of zwitterionic molecules with a protonated imidazolium group (imH+) and a negatively charged -CO2- group, whereas the tr-fragment was left neutral. Under the acidic hydrothermal conditions used, the organic ligand binds to molybdenum atoms either through [N-N]-tr or through both [N-N]-tr and µ2-CO2- units, which occur in protonated bidentate or zwitterionic tetradentate forms (trhisH+ and trhis, respectively). This leads to a new zigzag subtopological motif (3) of negatively charged polyoxomolybdate {Mo8O25}n2n- consisting of corner- and edge-sharing cis-{MoO4N2} and {MoO6} octahedra, while the tetradentate zwitterrionic trhis species connect these chains into a 2D net. Electronic spectra of the compounds showed optical gaps consistent with semiconducting behavior. The compounds were investigated as epoxidation catalysts via the model reactions of achiral and prochiral olefins (cis-cyclooctene and trans-ß-methylstyrene) with tert-butylhydroperoxide. The best-performing catalyst (1) was explored for the epoxidation of other olefins, including biomass-derived methyl oleate, methyl linoleate, and prochiral dl-limonene.

Composition Space Analysis in the Development of Copper Molybdate Hybrids Decorated by a Bifunctional Pyrazolyl/1,2,4-Triazole Ligand.

A bitopic ligand, 4-(3,5-dimethylpyrazol-4-yl)-1,2,4-triazole (Hpz-tr) (1), containing two different heterocyclic moieties was employed for the design of copper(II)-molybdate solids under hydrothermal conditions. In the multicomponent Cu(II)/Hpz-tr/Mo(VI) system, a diverse set of coordination hybrids, [Cu(Hpz-tr)2SO4]·3H2O (2), [Cu(Hpz-tr)Mo3O10] (3), [Cu4(OH)4(Hpz-tr)4Mo8O26]·6H2O (4), [Cu(Hpz-tr)2Mo4O13] (5), and [Mo2O6(Hpz-tr)]·H2O (6), was prepared and characterized. A systematic investigation of these systems in the form of a ternary crystallization diagram approach was utilized to show the influence of the molar ratios of starting reagents, the metal (Cu(II) and Mo(VI)) sources, the temperature, etc., on the reaction products outcome. Complexes 2-4 dominate throughout a wide crystallization range of the composition triangle, while the other two compounds 5 and 6 crystallize as minor phases in a narrow concentration range. In the crystal structures of 2-6, the organic ligand behaves as a short [N-N]-triazole linker between metal centers Cu···Cu in 2-4, Cu···Mo in 5, and Mo···Mo in 6, while the pyrazolyl function remains uncoordinated. This is the reason for the exceptional formation of low-dimensional coordination motifs: 1D for 2, 4, and 6 and 2D for 3 and 5. In all cases, the pyrazolyl group is involved in H bonding (H-donor/H-acceptor) and is responsible for π-π stacking, thus connecting the chain and layer structures in more complicated H-bonding architectures. These compounds possess moderate thermal stability up to 250-300 °C. The magnetic measurements were performed for 2-4, revealing in all three cases antiferromagnetic exchange interactions between neighboring Cu(II) centers and long-range order with a net moment below Tc of 13 K for compound 4.