G. G. Aleksandrov

Insertion of Ethyl Isothiocyanate into Tungsten Hexachloride: Crystal Structure of Ethyl-(4-Ethyl-5-Thioxo(1.2.4)dithiazolidin-3- ylidene)ammonium Oxopentachlorotungstate(VI)

A product of the insertion of two isothiocyanate molecules into the same W-Cl bond, namely, W-Cl-WCl5{N(Et)C(S)N(Et)C(S)Cl} (I), is synthesized by the reaction of WCl6 with EtNCS in a dichloroethane solution. The hydrolysis of compound I results in the formation of single crystals of the complex . The structure of crystals II is determined using X-ray diffraction. It is demonstrated that structural units of crystals II are the [WVIOCl5]− anionic complexes and the ethyl-(4-ethyl-5-thioxo[1.2.4]dithiazolidin-3-ylidene)ammonium cations.

Crystal structure of disordered diethylammonium oxo(1-hydroxyethane-1,1-diphosphonato)vanadate(IV) hydrate

Crystals of diethylammonium oxo(1-hydroxyethane-1,1-diphosphonato)vanadate(IV) hydrate have been synthesized, and their structure has been determined by X-ray diffraction analysis. In the crystal, three metal atoms of the disordered anionic complex in two orientations (the occupancies are 0.67 and 0.33) are linked in pairs by the tetradentate bis(chelate)-μ2-bridging ligands HnL4 − n with the formation of the [V3O4(HnL)3] cyclic trimers. As a first approximation, the coordination polyhedron of the V(1) and V(2) atoms in both orientations can be considered a tetragonal pyramid completed to a strongly distorted octahedron by the O atom of the terminal hydroxo ligand in the case of the V(2) atom or by the μ3-bridging oxo O atom for the V(1) atom. The diethylammonium cations and crystallization water molecules are disordered. The structural formula of the complex can be most correctly represented as [(C2H5)2NH2]2[{V4+O(μ 2-H2L)}3 (μ3-O)]0.67[{V4+(OH)(μ2-HL)} 3(μ3-O)]0.33 · 2H2O.

An unusual function of the anion of 1-hydroxyethane-1,1-diphosphonic acid (H4L): Crystal structure of [Ni(Phen)3](H7L2)0.5(H5L2)0.5 ⋅ 2H2O

Crystals of [Ni(Phen)3](H3L)2 ⋅ 2H2O (H4L is 1-hydroxyethane-1,1-diphosphonic acid) have been synthesized, and their structure has been determined by X-ray diffraction analysis. The cationic complexes [Ni(Phen)3]2+, the centrosymmetric dimeric anions H7L2− and H5L23−, and the molecules of crystallization water are the structural units of the crystal. The outer-sphere function of the H4L anions in transition metal compounds and also the presence of differently charged dimeric anions are revealed for the first time. The structural units are joined together by an extended system of hydrogen bonds, including symmetric (or pseudosymmetric) hydrogen bonds in dimeric anions (O⋯O, 2.436 and 2.466 Å). The Ni-N(Phen) bond lengths fall in the range 2.074–2.107 Å. The compound has the structural formula [Ni(Phen)3](H7L2)0.5(H5L2)0.5 ⋅ 2H2O.

Synthesis and crystal structure of trans-tetrachloro(C, C-dichloro-C-phenyl-methyl-nitrido)(phenylnitrilo)tungsten(VI), trans-[WCl4(NCCl2Ph)(NCPh)]

A product of the insertion, namely, trans-tetrachloro(C, C-dichloro-C-phenyl-methyl-nitrido)(phenylnitrilo) tungsten(VI), trans-[WCl4(NCCl2Ph)(NCPh)] (I), is synthesized by the reaction of WCl6 with PhCN in CCl4 under refluxing for 2 h. Judging from the characteristic IR bands ν(C≡N) and ν(W≡N), the complex synthesized is identical to the compound prepared earlier at room temperature. The crystal structure of complex I is determined using X-ray diffraction analysis. It is revealed for the first time that the coordination polyhedron of the tungsten atom in complex I is a distorted octahedron with four chlorine atoms in the equatorial plane. The axial positions are occupied by the N(1) atom [W-N(1), 2.265(13) Å] of the coordinated benzonitrile group and the N(2) atom [W-N(2), 1.732(13) Å] of the multiply bonded ligand NCCl2Ph.

Synthesis and the crystal and molecular structures of a germanium(IV)-copper(II) heteronuclear diethylenetriaminepentaacetate complex, [Cu(μ-HDtpa)2{Ge(OH)}2] · 12H2O

A procedure for synthesizing a mixed Cu-Ge complex with diethylenetriaminepentaacetic acid (H5Dtpa) is worked out, the compound [Cu{Ge(OH)(HDtpa)}2] · 12H2O is synthesized, and its crystal structure is studied by X-ray diffraction. In the centrosymmetric trinuclear molecular complex, the octahedral coordination of the peripheral Ge atom involves three O and two N atoms of the HDtpa4− ligand and the O atom of the hydroxo ligand. The central Cu atom is coordinated by four O and two N atoms of two HDtpa4− ligands, which form a tetragonal bipyramid (4 + 2). The HDtpa4− ligand fulfills an octadentate hexachelate bridging function (3N, 5O). The molecular complexes and crystallization water molecules are linked by an extended hydrogen-bond network.

Crystal structure of chloro[1-hydroxyethane-1,1-diphosphonato(3−)]ditin(II) monohydrate Sn2(HL)Cl · H2O

The synthesis and X-ray structure analysis of Sn2(HL)Cl · H2O, where HL3− is the anion of 1-hydroxyethane-1,1-diphosphonic acid, are reported. The coordination polyhedra of two independent tin(II) atoms are the Sn(1)O2Cl and Sn(2)O3 trigonal pyramids, in which one of the vertices is occupied by a lone electron pair (Sn-O, 2.144–2.218 Å and Sn-Cl, 2.573 Å). The pyramids are complemented by weaker Sn⋯O and Sn⋯Cl contacts to form severely distorted (3 + 3) octahedra. The SnO2Cl and SnO3 pyramids are linked by the HL3− bridging ligands into the [Sn2(HL)Cl]6 cyclic molecules, which, in turn, are joined by additional Sn⋯O, Sn⋯Cl, O(H2O)⋯O(L), and O(H2O)⋯Cl contacts with each other and with crystallization water molecules into a three-dimensional framework.

Crystal structure of triethanolammonium bis(1-hydroxyethane-1,1-diphosphonato)diaquazincate pentahydrate, [(OHCH2CH2)3NH][Zn(H2O)2(H2.5L)2] ⋅ 5H2O

The crystal structure of [(HOCH2CH2)3NH][Zn(H2O)2(H2.5L)2] ⋅ 5H2O, where H4L is 1-hydroxyethane-1,1-diphosphonic acid, was determined by X-ray diffraction. The anionic complex has a cis-octahedral structure. The zinc atom is coordinated by four O atoms of two bidentate chelate H2.5L1.5− ligands and two O atoms of water molecules. The Zn-O(L) bond lengths range between 2.050 and 2.175 Å, and the Zn-O(H2O) bond lengths are 2.105 and 2.133 Å. The anionic complexes, triethanolammonium cations, and molecules of crystallization water are interlinked by an extensive network of hydrogen bonds. The crystallographic data for isostructural complexes of cobalt and nickel are given.