Vladimir V. Bon

Oxonium (dihydrogen 1-amino­ethane-1,1-diyldiphospho­nato-κ2N,O)[hydrogen (1-amino-1-phosphono­ethyl)phospho­nato-κ2N,O]palladium(II) trihydrate

The title compound, (H3O)[Pd(C2H7NO6P2)(C2H8NO6P2)]·3H2O, was synthesized by the reaction of [Pd(H2O)4](NO3)2 with 1-aminoethane-1,1-diyldiphosphonic acid in aqueous solution. The asymmetric unit contains one molecule of the complex existing as an anion, an oxonium counter-ion and three solvent water molecules. The PdII ion occupies a position on a pseudo-twofold axis, which is not realized crystallographically. The slightly distorted square-planar coordination environment of the PdII ion consists of the O atoms from two phosphonic acid groups and two N atoms of the amino groups in cis positions. The crystal structure displays N—H⋯O and O—H⋯O hydrogen bonding, which creates a wide three-dimensional network.

Bis(1-ammonio­ethane-1,1-diyl­diphos­phonato-κ2O,O′)diaqua­cobalt(II) nona­hydrate

In the title compound, [Co(C2H8NO6P2)2(H2O)2]·9H2O, the CoII atom has a slightly distorted octahedral coordination environment consisting of four deprotonated phosphonate O atoms of two independent 1-aminoethylidendiphosphonate anions and complemented by the O atoms of two water molecules in cis positions. The anions exists in the zwitterionic form (protonated amino group and two deprotonated phosphonate O atoms) and constitute two six-membered chelate rings. The crystal structure also contains nine partly disordered uncoordinated water molecules, which create an extensive three-dimensional network of strong O—H⋯O and N—H⋯O hydrogen bonds.

trans-Bis[(1-ammonio­pentane-1,1-di­yl)diphospho­nato-κ2 O,O′]diaqua­copper(II)

In the title compound, [Cu(C5H14NO6P2)2(H2O)2], the CuII atom occupies a special position on an inversion centre. It exhibits a distorted octahedral coordination environment consisting of two O,O′-bidentate (1-ammoniopentane-1,1-diyl)diphosphonate anions in the equatorial plane and two trans water molecules located in axial positions. The ligand molecules are coordinated to the CuII atom in their zwitterionic form via two O atoms from different phosphonate groups, creating two six–membered chelate rings with a screw-boat conformation. The CuO6 coordination polyhedron is strongly elongated in the axial direction with 0.6 Å longer bonds than those in the equatorial plane. Intramolecular N—H⋯O hydrogen bonding helps to stabilize the molecular configuration. The presence of supramolecular —PO(OH)⋯O(OH)P— units parallel to (100) and other O—H⋯O and N—H⋯O hydrogen bonds establish the three-dimensional set-up.

cis-(Pyridin-2-ylcarbonimidodithio­ato-κ2S,S′)bis­(triphenyl­phosphane-κP)palladium(II)

The title compound, [Pd(C6H4N2S2)(C18H15P)2], was obtained as a minor product from the reaction of trans-PdCl2(PPh3)2 with piperazine-1,4-dicarbothioic acid bis(pyridin-2-yl)amide. The PdII atom displays a slightly distorted square-planar PdP2S2 geometry with a bidentately coordinated pyridin-2-ylcarbonimidodithioate ligand and two triphenylphosphine molecules, coordinated in cis positions. The crystal structure features weak π–π [centroid–centroid distance =3.7327(15) Å] and C–H⋯π interactions and contains an almost spherically shaped void of 50.4 Å3 per unit cell.

Poly[[μ2-(1Z,N′E)-2-(1,3-benzothia­zol-2-ylsulfan­yl)-N′-(2-oxidobenzyl­idene-κ2O:O)acetohydrazidato-κ2O,N′](pyridine-κN)copper(II)]

In the title compound, [Cu(C16H11N3O2S2)(C5H5N)]n, the CuII atom displays a square-pyramidal CuN2O3 coordination geometry with strong elongation in the vertex direction. The hydrazone molecule is coordinated to the CuII atom in a tridentate manner in the enolic form, creating five- and six-membered chelate metallarings. The pyridine molecule completes the square-planar base of the copper coordination environment. The crystal structure displays zigzag polymeric Cu—O—Cu chains along [001]. Several weak π–π interactions between benzothiazole rings were found in the same direction [centroid–centroid distances = 3.7484 (16), 3.7483 (16), 3.6731 (17) and 3.7649 (17) Å].

Bis[(1-ammonio­ethane-1,1-di­yl)diphospho­nato-κ2O,O′]diaqua­nickel(II) nona­hydrate

The title compound, [Ni(C2H8NO6P2)2(H2O)2]·9H2O, exhibits a slightly distorted octahedral coordination environment around the NiII atom. It contains two molecules of 1-aminoethylidenediphosphonic acid in the zwitterionic form, coordinated via O atoms from two phosphonate groups and creating two six-membered chelate rings. Two water molecules in cis positions complete the coordination environment of the NiII atom. The title compound contains nine partly disordered solvent water molecules, which create a three-dimensional network of strong O—H⋯O and N—H⋯O hydrogen bonds.

Reinvestigation of KMg1/3Nb2/3OPO4

The crystal structure of potassium magnesium niobium oxide phosphate, KMg1/3Nb2/3OPO4, which was described in the space group P4322 [McCarron & Calabrese, (1993 ▶). J. Solid State Chem. 102, 354–361], has been redetermined in the revised space group P41. Accordingly, the assignment of the space group P4322 and, therefore, localization of K at a single half-occupied position, as noted in the previous study, proved to be an artifact. As a consequence, two major and two minor positions of K are observed due to the splitting along [001], as first noted for KTiOPO4 structure analogues. It has been shown that the geometry of the {M II 1/3Nb2/3O6/2}∞ framework is almost unaffected by the lowering of symmetry.

{[1-(2-Amino-ethyl-amino)-1-methyl-ethyl]phospho-nato-κN,N',O}chloridopalladium(II) monohydrate.

In the title compound, [Pd(C5H14N2O3P)Cl]·H2O, the Pd(II) atom shows a slightly distorted square-planar geometry and forms two five-membered metallacycles, which both exhibit half-chair conformations. The crystal structure consists of layers propogating in the [100] direction which are connected into a three-dimensional network by strong N—H⋯Cl, N—H⋯O and O—H⋯O hydrogen bonds.

2-Hydroxy­amino-2-oxoacetohydrazide

In the title compound, C2H5N3O3, the hydroxamic group adopts an anti orientation with respect to the hydrazide group. In the crystal, molecules are connected by N—H⋯O and O—H⋯N hydrogen bonds into zigzag chains along the c axis.

[1-(2-Oxidobenzyl­idene)-4-phenyl­thio­semicarbazidato-κ3O,N1,S](pyridine-κN)copper(II)

In the structure of the title compound, [Cu(C14H11N3OS)(C5H5N)], the CuII atom exhibits a slightly distorted square-planar CuN2OS coordination polyhedron consisting of a phenyl O, an azomethine N and a thioamide S atom from the tridentate thiosemicarbazonate dianion, and the N atom of a pyridine molecule. The thiosemicarbazonate ligand exists in the thiol tautomeric form as an E isomer. Rotational disorder of the pyridine and phenyl rings in a 1:1 ratio of the respective components is observed. An extensive network of weak N—H⋯S, C—H⋯O, C—H⋯N and C—H⋯S hydrogen-bonding interactions consolidates the structure.