Copper(II) chloride and bromide complexes with 2‐methyl‐2H‐tetrazol‐5‐amine: an X‐ray powder diffraction study

The complex catena‐poly[[dibromidocopper(II)]‐bis(μ‐2‐methyl‐2H‐tetrazol‐5‐amine)‐κ²N⁴:N⁵;κ²N⁵:N⁴], [CuBr₂(C₂H₅N₅)₂]_n, (I), and the isotypic chloride complex catena‐poly[[dichloridocopper(II)]‐bis(μ‐2‐methyl‐2H‐tetrazol‐5‐amine)‐κ²N⁴:N⁵;κ²N⁵:N⁴], [CuCl₂(C₂H₅N₅)₂]_n, (II), were investigated by X‐ray powder diffraction at room temperature. The crystal structure of (I) was solved by direct methods, while the Rietveld refinement of (II) started from the atomic coordinates of (I). In both structures, the Cu atoms lie on inversion centres, adopting a distorted octahedral coordination of two halogen atoms, two tetrazole N atoms and two 5‐amine group N atoms. Rather long Cu—N_amine bonds allow consideration of the amine group as semi‐coordinated. The compounds are one‐dimensional coordination polymers, formed as a result of 2‐methyl‐2H‐tetrazol‐5‐amine ligands bridging via a tetrazole N atom and the amine N atom. In the polymeric chains, adjacent Cu atoms are connected by two such bridges.     

cis‐Amminedichloro­isopropyl­amine­platinum(II) by X‐ray powder diffraction analysis

The title compound, [PtCl₂(C₃H₉N)(NH₃)], was obtained from potassium tetra­chloro­platinate(II) by a two‐step route. Ab initio crystal structure determination was carried out using X‐­ray powder diffraction techniques. Patterson and Fourier syntheses were used for the atom locations and the Rietveld technique for the final structure refinement. The Pt coordination is close to planar, with Cl atoms in a cis orientation. Mol­ecules are combined into groups of two mol­ecules, with anti­parallel PtN₂Cl₂ planes and a shortest Pt⋯Pt distance of 3.42 Å. The mol­ecule groups are packed in a parquet motif into corrugated layers parallel to ab. The mol­ecules in the layers are linked by H—N⋯Cl hydrogen bonds.     

Dichloro[N,N‐dimethyl‐1‐(1‐methyl‐1H‐tetrazol‐5‐yl‐κN4)methanamine‐κN]copper(II)

The title compound, [CuCl₂(C₅H₁₁N₅)], is the first structurally characterized molecular chelate complex involving an α‐­amino­alkyl­tetrazole. There are two complex mol­ecules in the asymmetric unit. The ligand mol­ecules are bidentate. Both Cu atoms reveal rather distorted square‐planar coordinations. The complex mol­ecules are linked together by van der Waals interactions only.     

Packing forces in dichloridobis(3,5‐diphenyl‐1H‐pyrazole‐κN2)cobalt(II) dichloromethane hemisolvate

The title compound, [CoCl₂(C₁₅H₁₂N₂)₂]·0.5CH₂Cl₂, was crystallized from a binary mixture of dichloromethane and hexane and a dimeric supramolecular structure was isolated. The Co^II centre exhibits a distorted tetrahedral geometry, with two independent pyrazole‐based ligands occupying two coordination sites and two chloride ligands occupying the third and fourth coordination sites. The supramolecular structure is supported by complementary hydrogen bonding between the pyrazole NH group and the chloride ligand of an adjacent molecule. This hydrogen‐bonding motif yields a ten‐membered hydrogen‐bonded ring. Density functional theory (DFT) simulations at the PBE/6‐311G level of theory were used to probe the solid‐state structure. These simulations suggest that the chelate undergoes a degree of conformational distortion from the lowest‐energy geometry to allow for optimal hydrogen bonding in the solid state.     

Bis­[1,3‐bis(2‐methyl­tetrazol‐5‐yl‐κN4)­triazenido‐κN2]­nickel(II)

The title compound, [Ni(BMTT)₂], where BMTT is 1,3‐bis(2‐methyl­tetrazol‐5‐yl)­triazenide (C₄H₆N₁₁), presents a molecular complex with tridentate ligands. The tridentate mode of the ligand is realised through the central N atom of the triazene group and two N atoms of the two tetrazole rings. The [Ni(BMTT)₂] mol­ecule is the meridional isomer, with crystallographic symmetry in space group P4₂/n. The nickel centre has a distorted octahedral environment, with two axial Ni—N bonds of 2.041 (2) Å and four equatorial Ni—N bonds of 2.0739 (14) Å. The mol­ecules are linked together by van der Waals interactions only.     

(Glycylglycinato‐κ3O,N,N′)(2‐methyl‐1H‐benzimidazole‐κN3)copper(II) trihydrate

In the title compound, [Cu(C₄H₆N₂O₃)(C₈H₈N₂)]·3H₂O, the Cu^II atom is coordinated in a square‐planar manner by one O atom and three N atoms from glycylglycinate and 2‐methyl­benzimidazole ligands. The ternary complexes assemble into one‐dimensional chains through C—H⋯π inter­actions and direct N—H⋯O hydrogen bonding, as well as into hydrogen‐bonded water helices with branches which also link the complex chains into a three‐dimensional supra­molecular structure.     

Rhombohedral boron subnitride,B13N2, by X‐ray powder diffraction

The structure of the title compound consists of distorted B₁₂ icosahedra linked by N—B—N chains. The compound crystallizes in the rhombohedral space group Rm (No. 166). The unit cell contains four symmetry‐independent atom sites, three of which are occupied by boron [in the 18h, 18h (site symmetry m) and 3b (site symmetry m) Wyckoff positions] and one by nitrogen (in the 6c Wyckoff position, site symmetry 3m). Two of the B atoms form the icosahedra, while N atoms link the icosahedra together. The main feature of the structure is that the 3b position is occupied by the B atom, which makes the structure different from those of B₆O, for which these atom sites are vacant, and B_4+xC_1−x, for which this position is randomly occupied by both B and C atoms.     

cis‐Bis(3,6‐di­hydro‐2H‐1,2‐oxazine‐N)­di­iodo­platinum(II) and cis‐bis(3,4,5,6‐tetra­hydro‐2H‐1,2‐oxazine‐N)­di­iodo­platinum(II)

The title complexes, [Pt(C₄H₇NO)₂I₂], (I), and [Pt(C₄H₉NO)₂I₂], (II), possess similar square‐planar coordination geometries with modest distortions from ideality. For (I), the cis‐L—Pt—L angles are in the range 87.0 (4)–94.2 (3)°, while the trans angles are 174.4 (3) and 176.4 (3)°. For (II), cis‐L—Pt—L are 86.1 (8)–94.2 (6)° and trans‐L—Pt—L are 174.4 (6) and 177.4 (5)°. One 3,6‐di­hydro‐2H‐1,2‐oxazine ligand in (I) is rotated so that the N—O bond is out of the square plane by approximately 70°, while the N—C bond is only ca 20° out of the plane. The other oxazine ligand is rotated so that the N—C bond is about 80° out of the plane, while the N—O bond is out of the plane by approximately 24°. In (II), the 3,4,5,6‐tetra­hydro‐2H‐1,2‐oxazine ligands are also positioned with one having the N—O bond further out of the plane and the other having the N—C bond positioned in that fashion. Both ligands, however, are rotated approximately 90° compared with their positions in (I). In both complexes, this results in an unsymmetrical distortion of the I—Pt—N bond angles in which one is expanded and the other contracted. These features are compared to those of reported cis‐di­amine­di­iodo­platinum(II) complexes.     

A tetrazol‐5‐yl analogue of glycine, 5‐ammoniomethyl‐1H‐tetrazolide,and its copper(II) complex

A nonclassical tetrazole isostere of glycine, viz. zwitterionic 5‐ammoniomethyl‐1H‐tetrazolide, C₂H₅N₅, (I), crystallizes in the chiral P3₁ space group, similar to γ‐glycine. The crystal packing of (I) is determined by a set of classical hydrogen bonds, forming a three‐dimensional network that is practically the same as that in γ‐glycine. The Cu^II complex of (I), poly[[bis(μ₂‐5‐aminomethyl‐1H‐tetrazolido‐κ³N¹,N⁵:N⁴)copper(II)] dihydrate], {[Cu(C₂H₄N₅)₂]·2H₂O}_n, (II), is a layered coordination polymer formed as a result of tetrazole ring bridges. The Cu^II cations lie on inversion centres, are surrounded by four anions and adopt elongated octahedral coordination. Water molecules are located in the interlayer space and connect the layers into a three‐dimensional network via a system of hydrogen bonds.     

cis‐Bis(acetato‐κO)bis(dimethyl sulfide‐κS)platinum(II)

The title compound, cis‐[Pt(CH₃COO)₂(C₂H₆S)₂], crystallizes in the P2₁/c space group with a pseudo‐square‐planar coordination geometry. The complex forms centrosymmetric dimeric packing units, with C—H...O—Pt interactions and a short Pt...Pt distance [3.5868 (2) Å]. The coordination mode of the acetate ligands is monodentate and they are oriented almost perpendicular to the coordination plane. Cambridge Structural Database [Allen (2002). Acta Cryst. B 58 , 380–388] data show a preferred staggered conformation with respect to the coordination plane for Me₂S in complexes with Pt^II.     

Two two‐dimensional hydrogen‐bonded coordination networks: bis(3‐carboxybenzoato‐κO)bis(4‐methyl‐1H‐imidazole‐κN3)copper(II) and bis(3‐methylbenzoato‐κN)bis(4‐methyl‐1H‐imidazole‐κN3)copper(II) monohydrate

The title two‐dimensional hydrogen‐bonded coordination compounds, [Cu(C₈H₅O₄)₂(C₄H₆N₂)₂], (I), and [Cu(C₈H₇O₂)₂(C₄H₆N₂)₂]·H₂O, (II), have been synthesized and structurally characterized. The molecule of complex (I) lies across an inversion centre, and the Cu²⁺ ion is coordinated by two N atoms from two 4‐methyl‐1H‐imidazole (4‐MeIM) molecules and two O atoms from two 3‐carboxybenzoate (HBDC⁻) anions in a square‐planar geometry. Adjacent molecules are linked through intermolecular N—H...O and O—H...O hydrogen bonds into a two‐dimensional sheet with (4,4) topology. In the asymmetric part of the unit cell of (II) there are two symmetry‐independent molecules, in which each Cu²⁺ ion is also coordinated by two N atoms from two 4‐MeIM molecules and two O atoms from two 3‐methylbenzoate (3‐MeBC⁻) anions in a square‐planar coordination. Two neutral complex molecules are held together via N—H...O(carboxylate) hydrogen bonds to generate a dimeric pair, which is further linked via discrete water molecules into a two‐dimensional network with the Schläfli symbol (4³)₂(4⁶,6⁶,8³). In both compounds, as well as the strong intermolecular hydrogen bonds, π–π interactions also stabilize the crystal stacking.     

Dichloro­(propane‐1,3‐diamine‐κ2N,N′)platinum(II), dichloro­(propane‐1,3‐diamine‐κ2N,N′)­palladium(II) and μ‐4,9‐diaza­dodecane‐1,12‐diamine‐κ2N1,N4:κ2N9,N12‐bis­[dichloro­platinum(II)]

In the title compounds, [PtCl₂(C₃H₁₀N₂)], (I), [PdCl₂(C₃H₁₀N₂)], (II), and [Pt₂Cl₄(C₁₀H₂₆N₄)], (III), each metal atom lies in a distorted cis‐square coordination geometry. Compounds (I) and (II) are isostructural, and each complex has a mirror plane through the metal atom and the middle C atom of the propane‐1,3‐diamine ligand. In (III), the binuclear complex [Pt₂Cl₄(spn)] has an inversion center at the middle of the 4,9‐diaza­dodecane‐1,12‐diamine (spermine, spn) ligand. The six‐membered chelate rings in (III) adopt a chair form, which is unsymmetrical and less flattened than those in (I) and (II). In all three crystal structures, there are inter­molecular N—H⋯Cl hydrogen bonds.     

An X‐ray powder investigation of catena‐poly[copper(II)‐di‐μ‐chloro‐κ41:2Cl‐μ‐1,5‐dimethyl‐1H‐tetra­zole‐κ2N3:N4]

The crystal structure of the polymeric title complex, [CuCl₂(C₃H₆N₄)]_n, has been solved from laboratory X‐ray powder diffraction data collected at room temperature. The structural model obtained was refined with the Rietveld method using geometric soft restraints. There are two Cu atoms, two Cl atoms and one 1,5‐dimethyl­tetra­zole ligand in the asymmetric unit. Both Cu atoms lie on inversion centres and adopt essentially elongated octa­hedral coordination. Within the octa­hedra, the elongated axial positions are occupied by Cl atoms, while two Cl and two N atoms (N3 and N4 of the tetra­zole ring) are in equatorial sites. Each Cl atom forms an asymmetric bridge between neighbouring Cu atoms, which are also bridged via the N3—N4 bond of the tetra­zole ring. These bridges result in the formation of polymeric chains, running along the a axis, with weak C—H⋯Cl hydrogen bonds crosslinking the chains.     

cis‐Dichloro(dimethyl sulfoxide‐S)(2‐methoxypyridine‐N)platinum(II)

The title complex, [PtCl₂(C₆H₇NO)(C₂H₆OS)], exhibits square‐planar geometry. The plane of the pyridine ring makes a dihedral angle of 67.2 (3)° with the square plane of the metal center. The S—O bond is nearly aligned with the adjacent Pt—N bond, leaving the methyl groups of the di­methyl sulfoxide ligand to stagger the Pt—Cl bond.     

(2‐Aminopyrimidine‐κN1)aqua(pyridine‐2,6‐dicarboxylato‐κ3O2,N,O6)copper(II): X‐ray and DFT calculated structure

In the title compound, [Cu(C₇H₃N₂O₄)(C₄H₅N₂)(H₂O)], (I), pyridine‐2,6‐dicarboxylate (pydc²⁻), 2‐aminopyrimidine and aqua ligands coordinate the Cu^II centre through two N atoms, two carboxylate O atoms and one water O atom, respectively, to give a nominally distorted square‐pyramidal coordination geometry, a common arrangement for copper complexes containing the pydc²⁻ ligand. Because of the presence of Cu...X_bridged contacts (X = N or O) between adjacent molecules in the crystal structures of (I) and three analogous previously reported compounds, and the corresponding uncertainty about the effective coordination number of the Cu^II centre, density functional theory (DFT) calculations were used to elucidate the degree of covalency in these contacts. The calculated Wiberg and Mayer bond‐order indices reveal that the Cu...O contact can be considered as a coordination bond, whereas the amine group forming a Cu...N contact is not an effective participant in the coordination environment.     

Diaqua­bis[5‐(pyrazin‐2‐yl‐κN1)‐1H‐tetra­zolato‐κN1]manganese(II) and diaqua­bis[5‐(pyrazin‐2‐yl‐κN1)‐1H‐tetra­zolato‐κN1]zinc(II)

The two new title complexes, [Mn(C₅H₃N₆)₂(H₂O)₂] and [Zn(C₅H₃N₆)₂(H₂O)₂], are isomorphous. In both compounds, the metal atom is located on an inversion center and is coordinated by four N atoms from two 5‐(pyrazin‐2‐yl)‐1H‐tetra­zolate anions in the basal plane and by two O atoms of water ligands in the apical positions to form a distorted octa­hedral geometry. Inter­molecular hydrogen‐bond inter­actions between the uncoordinated N atoms of the tetra­zolate anions and the H atoms of the water mol­ecules lead to the formation of a three‐dimensional network.     

Di‐μ‐hydroxo‐bis{(aceto­nitrile)dibenzyl(6‐methyl‐2‐pyridylmethyl)amine‐κ2N,N]copper(II)} bis(perchlorate)

The title compound corresponds to a copper(II) dimer, [Cu₂(OH)₂(C₂H₃N)₂(C₂₁H₂₂N₂)₂](ClO₄)₂, where the metal centres are μ₂‐bridged by hydroxo groups. The coordination of each copper(II) centre is a slightly distorted square‐based pyramid, with two N atoms from dibenzyl(6‐methyl‐2‐pyridylmethyl)amine (BiBzMePMA) and two hydroxo O atoms occupying the basal positions, and the aceto­nitrile N atom at the apical position. The dimer is centrosymmetric, with a crystallographic inversion centre midway between the two Cu atoms [Cu⋯Cu = 2.9522 (9) Å]     

The layered structure of poly­[[di‐μ‐chloro‐bis­[chloro(2‐ethyl­tetrazole‐κN4)copper(II)]]‐di‐μ‐2‐ethyl­tetrazole‐κ2N1:N4]

In the polymeric title complex, [CuCl₂(C₃H₆N₄)₂]_n, there are two ligands in the asymmetric unit. The Cu atom adopts an elongated octahedral geometry, with two 2‐ethyl­tetrazole ligands [Cu—N = 2.0037 (16) and 2.0136 (16) Å] and two Cl atoms [Cu—Cl = 2.2595 (6) and 2.2796 (6) Å] in equatorial positions. A Cl atom and a symmetry‐related 2‐ethyl­tetrazole mol­ecule [Cu—Cl = 2.8845 (8) Å and Cu—N = 2.851 (2) Å] lie in the axial positions of the octahedron. One of the two 2‐­ethyltetrazole ligands of the asymmetric unit exhibits bidentate binding to two Cu atoms through two N atoms of the tetrazole ring, whereas the other ligand is coordinated in a monodentate fashion via one tetrazole N atom. The Cu‐atom octahedra form dimer entities by sharing edges with equatorial and axial Cl atoms. The dimers are linked together through the 2‐ethyl­tetrazole ligands to form one‐dimensional polymeric zigzag chains extending along the b axis. The chains are connected into infinite layers parallel to the (10) plane via the 2‐ethyl­tetrazole ligands.     

1,1′‐Methylenedipyridinium tetrachloridocuprate(II) and bis[tetrachloridoaurate(III)] hybrid salts by X‐ray powder diffraction

In order to explore the potential propensity of the 1,1′‐methylenedipyridinium dication to form organic–inorganic hybrid ionic compounds by reaction with the appropriate halide metal salt, the organic–inorganic hybrid salts 1,1′‐methylenedipyridinium tetrachloridocuprate(II), (C₁₁H₁₂N₂)[CuCl₄], (I), and 1,1′‐methylenedipyridinium bis[tetrachloridoaurate(III)], (C₁₁H₁₂N₂)[AuCl₄]₂, (II), were obtained by treatment of 1,1′‐methylenedipyridinium dichloride with CuCl₂ and Na[AuCl₄], respectively. Both hybrid salts were isolated as pure compounds, fully characterized by multinuclear NMR spectroscopy and their molecular structures confirmed by powder X‐ray diffraction studies. The crystal structures consist of discrete 1,1′‐methylenedipyridinium dications and [CuCl₄]²⁻ and [AuCl₄]⁻ anions for (I) and (II), respectively. As expected, the dications form a butterfly shape; the Cu^II centre of [CuCl₄]²⁻ has a distorted tetrahedral configuration and the Au^III centre of [AuCl₄]⁻ shows a square‐planar coordination. The ionic species of (I) and the dication of (II) each have twofold axial symmetry, while the two [AuCl₄]⁻ anions are located on a mirror‐plane site. Both crystal structures are stabilized by intermolecular C—H...Cl hydrogen bonds and also by Cl...π interactions. It is noteworthy that, while the average intermolecular centroid–centroid pyridinium ring distance in (I) is 3.643 (8) Å, giving strong evidence for noncovalent π–π ring interactions, for (II), the shortest centroid–centroid distance between pyridinium rings of 5.502 (9) Å is too long for any significant π–π ring interactions, which might be due to the bulk of the two [AuCl₄]⁻ anions.     

In search of conformationally chiral square‐planar complexes: dichloridobis(2‐methoxypyridine‐κN)copper(II)

The title compound, [CuCl₂(C₆H₇NO)₂], was synthesized during a study of conformationally chiral square‐planar coordination compounds. The coordination geometry deviates from the square‐planar geometry generally adopted by copper(II) chloride complexes with pyridine ligands towards a tetrahedral arrangement of ligands. The complex is conformationally chiral but crystallizes in a centrosymmetric space group with both enantiomers present in the unit cell.