CIF Files Research Articles

New Gold(I) Complexes with 1,5-Diaza-3,7-Diphosphacyclooctanes: Synthesis and Structures

New bi- and trinuclear gold(I) complexes are synthesized by the reactions of gold(I) chloride or tetrahydrothiophenegold(I) chloride with 1,5-di(p-tolyl)-3,7-diphenyl-1,5,3,7-diazadiphosphacyclooctane taken in various ratios. The structures of the synthesized compounds are confirmed by NMR spectroscopy, elemental analysis, and X-ray diffraction analysis (CIF files ССDC nos. 1974032 (I) and 1974031 (II)). Unlike P-pyridyl-containing 1,5-diaza-3,7-diphosphacyclooctanes, P-phenyl-substituted ligands undergo no rearrangements with ring expansion during the formation of the trinuclear gold(I) complexes.

Cu(II) and Co(II) Complexes with (4Z)-4-[(2-Diethylaminoethylamino)methylene]-5-Methyl-2-Phenylpyrazol-3-one: Synthesis, Magnetic Properties, and Crystal Structures

(4Z)-4-[(2-Diethylaminoethylamino)methylene]-5-methyl-2-phenylpyrazol-3-one (НL, product of the condensation of 5-hydroxy-3-methyl-1-phenylpyrazole-4-carbaldehyde with N,N-diethylethylenediamine) and its complexes CuL2 (I) and Co(L)CH3COO · CH3OH · H2O (II) are synthesized. The structures and compositions of the synthesized compounds are determined by elemental analysis, 1Н NMR and IR spectroscopy, and X-ray diffraction analysis (CIF files CCDC nos. 1971770 (I) and 1971772 (II)). Bis(chelate) pentacoordinated complex I has a distorted tetragonal pyramidal structure, and a distorted octahedral structure with the monodentate acetate anion and methanol and water molecules is observed for monochelate complex II.

The Coordination- and Photochemistry of a New Dinuclear Copper(I) Bis(diphenylphosphino)methane (1 : 2) Complex

In our attempts to identify new species in the preparation of copper(I)-Dppm (Dppm = bis(diphenylphosphino)methane) complexes under the condition of excess Dppm, we isolated and analyzed a new binuclear copper(I)-Dppm complex, namely, [(μ2-η1,η1-Dppm)2Cu2(η1-Dppm)2(μ2-Cl)](BF4) (I). We report here the synthesis, crystal structure (CIF file CCDC no. 1912269), characterizations by various spectroscopic (IR, 1HNMR, UV−Vis, powder XRD) techniques and the thermal and luminescent properties of this complex. Its X-ray crystal structure reveals a discrete cationic binuclear copper(I)-Dppm (1 : 2) species for the first time. The binuclear copper centres are bridged by a pair of cis-Dppm molecules and one chloride ion, and further consolidated by two trans-Dppm molecules in mono-dentate fashion. It exhibits cyan photoluminescence in the solid state at room temperature. This work not only addresses the concern of structural information of binuclear copper(I)-Dppm (1 : 2) complex, but also provides a new way to incorporate sterically hindered ligands into the {Cu(μ2-η1,η1-trans-Dppm)2Cu} scaffold for novel luminous properties.

Mononuclear Antimony(V) Catecholate Complexes with Additional Pyridine Ligands

A series of triarylantimony(V) complexes with p-dimethylaminopyridine and р-cyanopyridine of the general formulas [(Cat)SbAr3(р-Me2N–Py)] (complexes I–IV) and [(Cat)SbAr3(р-CN–Py)] (complexes V–VII) has been synthesized. Their molecular structures and electrochemical properties have been studied. 3,6-Di-tert-butyl-o-benzoquinone, 4,5-piperazine-1,4-diyl-3,6-di-tert-butyl-o-benzoquinone, and 4,5-dichloro-3,6-di-tert-butyl-o-benzoquinone are used as redox-active ligands. The molecular structures of several complexes in the crystalline state are determined by X-ray diffraction analysis (CIF files CCDC nos. 1974173 (I ⋅ 0.5toluene), 1974174 (II ⋅ 2toluene), 1974175 (V), 1974176 (VI ⋅ hexane), and 1974177 (VII)). All complexes have a distorted octahedral structure, and an additional neutral pyridine ligand occupies one of the apical positions. Electrochemical transformations of the complexes are studied by cyclic voltammetry in a dichloromethane solution. The introduction of substituted pyridine into the molecule of the complex does not change the electrooxidation mechanism of the complexes. For all complexes with р-dimethylaminopyridine, both oxidation potentials are shifted to the cathodic region (0.13–0.21 V for the potential of the first oxidation process and to 0.3–0.4 V for the potential of the second oxidation process). A similar shift for the complex with p-cyanopyridine is less pronounced (0.05 V for the potential of the first oxidation process of complex V as compared to that of complex I).

Influence of Substituents in the Aromatic Fragment of the Benzoate Anion on the Structures and Compositions of the Formed {Cd–Ln} Complexes

The reactions of Cd(NO3)2 ∙ 4H2O and Eu(NO3)3 ∙ 6H2O with potassium salts of the benzoic acid derivatives and 2,2'-bipyridine (Bipy) in ethanol, under the same synthesis conditions, afford the homo- and heterometallic complexes: [Eu2Cd2(BA)8(NO3)2(Bipy)2] (I, BA is benzoic acid anion), [Ln2Cd2(4-TBA)10(Bipy)2] (Ln = Eu (II), Tb (III); 4-TBA is 4-(trifluoromethyl)benzoic acid anion), [Cd(4-CBA)2(H2O)(Bipy)] (IV, 4-CBA is 4-cyanobenzoic acid anion), [Cd(PFBA)2(H2O)(Bipy)]n (V, PFBA is pentafluorobenzoic acid anion), and [Cd2(4-APFBA)4(Bipy)2] ∙ 4H2O (VI, 4-ATFBA is 4-amino-2,3,5,6-tetrafluorobenzoic acid anion). The structures of new complexes I, II, IV, and VI are determined by X-ray structure analysis (CIF files CCDC nos. 1970348, 1970350, 1970347, and 1970351, respectively). The isostructural character of complexes II and III is confirmed by X-ray diffraction analysis. The structures and compositions of the series of isolated compounds I–VI are determined by the nature of substituents in the benzoate anion. The photoluminescence properties of compounds II and III are studied.

A Keggin-Type Tungstovanadate-Based Hybrid Compound: Synthesis, Crystal Structure, and Electrocatalytic Oxidation of Ascorbic Acid

A new V-centered Keggin polyoxometalate-based inorganic-organic hybrid (HPpz)3[VW12O40] (I) (Ppz = piperazine) has been hydrothermal synthesized and characterized by IR spectroscopy, UV−Vis spectroscopy, elemental analysis and single-crystal X-ray diffraction (CIF file CCDC no. 1835683). Compound I belongs to the rhombohedral space group $$R\bar {3}c$$ and displays a three-dimensional supramolecular structure. The band gap energy value calculated for compound I was observed to be 1.30 eV using UV−Vis-NIR absorption spectrum. Furthermore, electrocatalytic performance of I has also been investigated in details.

Coordination Polymer and Monomer with the Cd(NO3)2 Fragment Containing 2-Amino-5-Bromopyridine: Synthesis, Structures, NMR Study, and Luminescence Properties

The reactions of Cd(NO3)2 ⋅ 4H2O with 2-amino-5-bromopyridine (Аbp) afford compounds [Cd(NO3)2(Аbp)(H2O)]n (I) and [Cd(NO3)2(Abp)2(H2O)2] (II). The structures of both complexes are determined by single-crystal X-ray structure analysis (CIF files CCDC nos. 1938624 (I) and 1959680 (II)). Compound I is a coordination 1D polymer in which two chelate-bonded $${\text{NO}}_{3}^{ - }$$ groups act as bridges. The coordination polyhedron of the octacoordinated central cadmium atom in compound I consists of seven oxygen atoms (one oxygen atom of water and six atoms of the $${\text{NO}}_{3}^{ - }$$ groups) and one nitrogen atom of Abp, being a triangular dodecahedron. Complex II is a mononuclear molecule in which the octahedral coordination polyhedron of Cd is formed by four oxygen atoms of two water molecules and two $${\text{NO}}_{3}^{ - }$$ groups and two oxygen atoms of two molecules of the Abp cycle. In both complexes, the amino group of Abp is not involved in coordination with the metal. Compound I is studied by 1H, 31C, and 15N NMR spectroscopy of a solution of the polymer complex in CD3CN, and the most substantial difference in the chemical shifts of the bound and free Abp ligands is observed in the 15N NMR spectra (37 ppm). According to the data of luminescence spectroscopy, compounds I and II exhibit an emission in a range of 430–690 nm.

Bioisostere Modifications of Cu2+ and Zn2+ with Pyromucic Acid Anions and N-Donors: Synthesis, Structures, Thermal Properties, and Biological Activity

Mono- and binuclear complexes [Cu(Fur)2(Phen)] (I), [Cu2(Fur)4(Py)2] (II), [Cu(Fur)2-(Py)2(H2O)] (III), and [Zn2(Fur)4L2] (L = Py (IV), Phpy (V)) are synthesized using the reactions of copper(II) and zinc(II) acetates with anions of pyromucic acid (2-furancarboxylic acid (HFur)) and N‑donor ligands (pyridine (Py), 4-phenylpyridine (Phpy), and 1,10-phenanthroline (Phen)) in acetonitrile. The copper complexes with pyridine are successively formed from the same reaction mixture: at first binuclear complex II is formed and then mononuclear complex III is formed. All compounds are isolated as single crystals, and their structures are determined by X-ray structure analysis (CIF files CCDC nos. 1974386 (I), 1974388 (II), 1974389 (III), 1974387 (IV), and 1974385 (V)). The thermal behavior of complexes II and III is studied by simultaneous thermal analysis. The biological activity in vitro of all complexes is determined toward the nonpathogenic mycobacterial strain Mycolicibacterium smegmatis. Complexes I and V exhibit a high biological activity and are promising for further studies of antitubercular activity.

Synthesis, Structure, Photoluminescent, and Semiconductor Properties of a Novel Hg–Pr Complex

A novel Hg-Pr compound [Hg3PrCl9(HIA)(IA)3]nnCl · 2nH3O · 4nH2O (I) (HIA = isonicotinic acid) is prepared through the hydrothermal reactions and structurally characterized by X-ray diffraction technique (CIF file CCDC no. 1831958). This compound is characterized by a 2D organic-inorganic hybrid layer structure. Solid-state photoluminescence measurement reveals that it exhibits a photoluminescence emission in the blue region. These photoluminescence emissions correspond to the characteristic emission 3H4–3PJ transitions (J = 2, 1, and 0, respectively) of Pr3+ ions. Solid-state UV−Vis diffuse reflectance spectrum discovers that the existence of a wide optical band gap of 3.39 eV.

New Gallium Hydrides with Dianionic Acenaphthene-1,2-Diimine Ligands

Heating of a solution of [(Dpp-bian)GaH2] (I) (Dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) in pyridine leads to elimination of a hydrogen atom and reduction of the diimine ligand to dianion, resulting in the complex [(Dpp-bian)GaH(Py)] (II). The reaction of I with 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (i-Pr2ImMe) is accompanied by a similar process, with the reaction product being identified as [(Dpp-bian)GaH(i-Pr2ImMe)] (III). Diamagnetic derivatives II and III were characterized by 1H NMR spectroscopy. The molecular structure of compound II was established by X-ray diffraction (CIF file CCDC no. 1973549).

Triphenylantimony(V) Catecholates Based on 3,6-Di-tert-Butyl-2,5-Dihydroxy-1,4-Benzoquinone

2,5-Dihydroxy-3,6-di-tert-butyl-p-benzoquinone (QtBuDiol) reacts with Ph3SbBr2 in toluene in the presence of triethylamine to yield the ionic complex [Et3NH]+[(DionetBuDiolate)SbPh3Br]– (I). The same reaction in methanol leads to complete displacement of bromide ions from the antimony coordination sphere and gives triphenylantimony(V) 1,2-diolate (DionetBuDiolate)SbPh3 · MeOH (II · MeOH). The molecular structure of the complexes was determined by X-ray diffraction (CIF files CCDC no. 1960681 (I · toluene) and 1960682 (II · 2MeOH)). Both complexes are characterized by quinoid bond distribution in the six-membered carbon rings and by C=O double bonds in the Ph3SbO2C6(t-Bu)2O2 moieties. Formally, the complexes can be considered as 3,6-di-tert-butyl-o-benzoquinone derivatives with the organometallic Ph3SbO2 group in positions 4 and 5 of the quinone ring. The electrochemical reduction of II · MeOH in dichloromethane occurs at E1/2 = –1.52 V, which is significantly shifted to the cathodic region relative to the data for 3,6-di-tert-butyl-o-benzoquinone (E1/2 = –0.51 V). This redox potential shift indicates a significant decrease in the electron-withdrawing properties of the o-quinoid moiety, which is caused by the effect of the electron-donating catecholate metallacycle.

New Heteroligand Europium and Gadolinium Formate Triazole Dicarboxylates: Synthesis, Structures, and Luminescence Properties

Complexes {(NMe2H2)[Ln(TDA)(HCOO)] ∙ 0.5H2O)} are prepared by the solvothermal synthesis in a water–dimethylformamide (1 : 1) system from a mixture of 1,2,3-triazole-4,5-dicarboxylic acid (H3TDA), NaOH, and Ln(NO3)3 (Ln = Eu, Gd). The crystal structure of the europium complex is determined by X-ray structure analysis (CIF file CCDC no. 1939689). This compound is shown to be the ionic metal-organic framework, where the cavities in the anionic structure of [Eu(TDA)(HCOO)]– are partially occupied by the dimethylammonium cations and water molecules. The study of the luminescence spectra of the gadolinium derivative gives the energy of the triplet level of the H3TDA ligand (~25 300 cm–1), the value of which makes it possible to efficiently sensitize the luminescence of rare-earth metal ions, in particular, Eu3+. The decay kinetics and the emission and excitation spectra of the heterometallic derivatives {(NMe2H2)[Gd1 – xEux(TDA)(HCOO)] ∙ 0.5H2O)} are studied. The dilution of europium with gadolinium results in a substantial decrease in the concentration quenching of the europium luminescence and an increase in the observed lifetimes of the excited state of Eu3+.

Syntheses, Crystal Structure, and Magnetic Property of a New Mn(II) Complex with an Aromatic N-heterocyclic Tetracarboxylic Acid Ligand

A new 2D Mn(II) complex named as [Mn3(HL)2(H2O)6]n (I) (H4L = 3-(2,4-dicarboxyphenyl)-2,6-dicarboxypyridine) was synthesized and characterized by IR, elemental analysis, and single-crystal X-ray diffraction method (CIF file CCDC no. 1915189). The complex crystallizes in the monoclinic space group C2/c with Z = 4, a = 20.6597(11), b = 9.0949(5), c = 20.6041(12) A, β = 110.056(6)°. The crystal consists of trinuclear Mn(II) ion clusters {Mn3} which are linked by four independent HL3– ligands and these trimeric units are connected into 2D structure by pentadentate HL3– ligand in alternate bis(bridging) and chelated coordination modes. Thermogravimetry, powder X-ray diffraction, and magnetic measurement experiments are also carried out to determinethe thermal stability, phase purity and magnetism. The results show that weak antiferromagnetic interactions occur between the Mn(II) centers within bridging trinuclear {Mn3} cluster.

Iron(II) and Cobalt(II) Complexes with 2,6-Bis(1,4-Diphenyl-5-Hydroxy-1H-Pyrazol-3-yl)pyridine: Synthesis, Structures, and Spin States

The reactions of 2,6-bis(1,4-diphenyl-5-hydroxy-1H-pyrazol-3-yl)pyridine (L), which is the first representative of a series of 2,6-bis(pyrazol-3-yl)pyridine ligands bearing substituents in positions 1 and 4 of the pyrazol-3-yl ring, with the divalent iron and cobalt salts afford new Со(II) and Fe(II) complexes: [Co(L)2](ClO4)2 (I) and [Fe(L)2](ClO4)2 (II). The compounds are isolated in the individual state and characterized by elemental analysis, NMR spectroscopy, and X-ray diffraction analysis (CIF files CCDC nos. 1967892 (I) and 1967893 (II)). According to the data obtained, the transition metal ion in complexes I and II exists in the high-spin state (S = 3/2 for Co(II) and S = 2 for Fe(II)) in a range of 120–345 K, and the proposed modification of the ligand does not lead to the temperature-induced spin transition in both the solution and crystalline state.

Nickel(II) Complexes with Mono(imino)pyrrole Ligands: Preparation, Structure, and MMA Polymerization Behavior

A simplified synthetic method was initiated to prepare the corresponding nickel complexes NiL2 (I–III) with direct condensation of mono(imino)pyrroles (L1–L3) and nickel dichloride, the structures and methyl methacrylate (MMA) catalytic polymerization behavior of this series of mono(imino)pyrrole nickel complexes were presented. The mono(imine)pyrrole ligands and the corresponding nickel complexes were determined by 1H NMR, 13C NMR, IR and MS, etc. Complexes I and III were further characterized by X-ray crystal diffraction (CIF files CCDC nos. 1890965 (I), 1890964 (III)). Both of the structures showed that the ligand chelated to nickel with 2 : 1 molar ratio. The systematic studies were focused on the relationship between the catalytic behavior of these complexes for MMA polymerization and catalyst structure, reaction time, reaction temperature, and ratio of monomer with catalyst. The optimum reaction conditions of the molar ratio of monomer to catalyst is of 1200 : 1, the polymerization temperature of 100°C, time of 10 h, the nickel complex with two bulky substituents on the o-position of phenyl ring linked with imine showed excellent catalytic activities for MMA polymerization (4.791 × 104 g mol–1 h–1), high molecular weight (Mn = 65.873 × 103 g mol–1), and narrow molecular mass distribution (polymer dispersity index = 3.9877), and azodiisobutyronitrile acted as co-catalyst during MMA polymerization.

Molecular Structure and Photoluminescence Behavior of the Zn(II) Carboxylate Complex with Pyrazino[2,3-f][1,10]phenanthroline

A new complex [Zn(Piv)2(Pyzphen)] (I) was prepared by the reaction of pyrazino[2,3-f][1,10]phenanthroline (Pyzphen) with Zn(II) pivalate [Zn(Piv)2]n. An X-ray diffraction study (CIF file CCDC no. 1912821) revealed that complex I has a mononuclear structure, with ZnN2O4 coordination unit being a distorted trigonal prism. Quantum chemical simulation of dimerization of complex I, resulting in the hypothetical binuclear product [Zn(Piv)2(Pyzphen)]2 (II), showed that two energy demanding transition states present on the path of association of the complex molecules may prevent the experimental isolation of binuclear complex II. According to the results of luminescence studies of the Pyzphen ligand and complex I, the ligand emission band shifts to the blue region upon coordination to zinc(II) ion.

Photoluminescence of the Coordination Zinc Compounds with 3-Methyl-4-Formyl-1-Phenylpyrazol-5-one Acylhydrazones

New coordination zinc compounds based on 3-methyl-4-formyl-1-phenylpyrazol-5-one acylhydrazones [Zn(L)(CH3COO)Solv] (Solv is H2O (I), Py (II)) are synthesized in order to search for new luminophores demonstrating efficient photoluminescence in the visible range. Complexes I and II are characterized by elemental and thermogravimetric analyses, mass spectrometry, and UV and IR spectroscopy. The structures of two complexes [Zn(L5)(CH3COO)H2O] and [ZnL4(CH3COO)Py] are determined by X-ray structure analysis (CIF files CCDC nos. 1958400 and 1958401, respectively). Complexes I and II demonstrate luminescence in the visible range with a maximum at 414–536 nm and a quantum yield of 9.5–64% depending on the nature of the acyl fragment.

Imidazole Multi-Carboxylate-Based 2D Cd(II) MOF: Preparation, Crystal Structure, and Properties

By adopting one imidazole multi-carboxylate ligand, 2-(3-carboxylphenyl)-1H-imidazole-4,5-dicarboxylic acid (m-CPhH4IDC) and one N-containg ligand, 2,2′-bipyridine (2,2′-Bipy) to react with Cd(NO3)2, under solvothermal condition, a two-dimensional metal-organic framework, {[Cd6(m-CPhHIDC)4(2,2′-Bipy)6] · 4H2O}n (I) has been sucessfully constructed. The structure has been determined by single-crystal X-ray diffraction analysis (CIF files CCDC no. 1480230) and further characterized by elemental analyses, IR spectra, and thermogravimetric analysis. MOF I exhibits a rare (3,4)-connected 2D structure bearing two kinds of organic ligands. According to the crystal data, the coordination ability and mode of the imidazole multi-carboxylate ligand are discussed. Furthermore, the thermal stability and solid-state photoluminescent properties of MOF I have been investigated.

Acetohydroxamate-coordinated Oxovanadium(V) Complexes with Halide Containing Hydrazones: Synthesis, Characterization, X-ray Crystal Structures, and Antibacterial Activity

Two oxovanadium(V) complexes, [VO(L)(L1)] (I) and [VOLL2] (II), where L = acetohydroxamate, H2L1 = 2-bromo-N'-(2-hydroxybenzylidene)benzohydrazide, H2L2 = 2-chloro-N'-(2-hydroxybenzylidene)benzohydrazide,have been synthesized by reaction of VO(Acac)2 with acetohydroxamic acid and hydrazone ligands, and characterized by elemental analyses, IR, UV-Vis, 1H NMR, molar conductivity, and X-ray single crystal structural determination (CIF file CCDC nos. 1911887 (I), 1911888 (II)). The hydrazone ligands coordinate to the V atoms through phenolate oxygen, imino nitrogen, and enolate oxygen atoms. The acetohydroxamate ligand coordinate to the V atoms through the two oxygen atoms. The V atoms are in octahedral coordination with the sixth site coordinated by an oxo group. The antibacterial property of the complexes and the hydrazones against the bacteria B. subtilis, E. coli, P. putida, and S. aureus were studied. Both complexes exhibit remarkable antibacterial properties on B. subtilis and S. aureus comparable to Penicillin.

Database of open-framework aluminophosphate structures

Open-framework aluminophosphates are an important class of inorganic crystalline compounds because of their rich structural chemistry and diverse properties. We have collected 312 open-framework aluminophosphate crystal structures from published literature and established a database for these structures. For each aluminophosphate structure, we have assigned a unique index code and extracted its key chemical and crystallographic information from the original literature and the associated CIF file, such as the name, chemical formula, extra-framework species, Al/P ratio, space group, and unit cell parameters of the compound. More importantly, we have calculated the topological features for each aluminophosphate framework, including local connectivity, framework dimension, coordination sequences, vertex symbols, topology density, and the largest ring. To help experimental chemists identify their products, we have also calculated theoretical XRD peaks for all aluminophosphate structures. This database will provide important insight into understanding the structural chemistry of open-framework aluminophosphate compounds.