In the title compound, [PtCl₄(C₁₄H₁₁N)₂], the Pt atom lies on an inversion center and has a distorted octa­hedral environment. The main geometric parameters are Pt—N = 1.960 (5) Å, and Pt—Cl = 2.3177 (12) and 2.3196 (12) Å. The NC bond is a typical triple bond [1.137 (7) Å]. The Pt—NC—C unit is almost linear, with Pt—N—C and N—C—C angles of 174.6 (4) and 177.1 (6)°, respectively.

In the title complex, cis-[PtCl₄(C₃H₄N₂)₂], the Pt^IV ion lies on a twofold rotation axis and is coordinated in a slightly distorted octa­hedral geometry. The dihedral angle between the imidazole rings is 69.9 (2)°. In the crystal, mol­ecules are linked by N—HCl hydrogen bonds, forming a three-dimensional network.

In the title centrosymmetric complex, trans-[PtCl₂(C₆H₁₀N₂)₂], the Pt^II centre is coordinated by two piperidine-1-carbonitrile ligands and two chloro ligands, resulting in a typical square-planar geometry. The C-N distance between the nitrile and piperidine group [1.306 (4) Å] clearly indicates that this bond is not a pure single bond, being closer to a C=N double bond. This points to a noticeable contribution of the bipolar structure [Pt]-N^-=C=N⁺R₂ in the resonance hybrid of the push-pull nitrile ligand.

The title compounds, chloro­tris­(di­methyl sulfide-κS)platinum(II) hexa­fluoro­phosphate, [PtCl(C₂H₆S)₃]PF₆, and bromotris­(di­methyl sulfide-κS)­platinum(II) hexa­fluoro­phos­phate, [PtBr(C₂H₆S)₃]PF₆, are isomorphous and are composed of [PtX(dms)₃]⁺ complex cations (X = Cl and Br, and dms is di­methyl sulfide) and PF₆⁻ anions. The Pt atom is coordinated by three S atoms and one X atom in a pseudo-square-planar coordination, with Pt—S distances in the range 2.293 (1)–2.319 (2) Å. Two dms ligands have a staggered conformation with respect to the coordination plane, while the third is rotated by ∼90° compared with the orientation of the other two. The packing can be described as consisting of [PtX(dms)₃]₂(PF₆)₂ units with a centre of symmetry. In this description, the Pt^II atom has a pseudo-octahedral coordination, with four normal bonds and two long weak interactions. Density-functional theory calculations show that a conformation in which one dms ligand is not staggered is less favourable than having all three dms ligands staggered.

The title complex, [PtCl₄(C₁₂H₂₄N₄O₂)] or trans-[PtCl₄{NH= C(Et)ON=CMe₂}₂], possesses a crystallographically imposed centre of symmetry. The coordination polyhedron of the complex is a slightly distorted octa­hedron. The two imino ligands are mutually trans. This configuration is stabilized by intra­molecular N—HN hydrogen bonding between the imine H atom and the oxime N atom.

The title compound, [Pt(C₃H₃N₂)Cl₃(C₃H₄N₂)₂], has mirror symmetry. The Pt^IV atom has a slightly distorted octa­hedral geometry, with three facial Cl atoms and three N atoms, the latter from one pyrazolate (pz) and two pyrazole (pzH) ligands. There is an intra­molecular N—HNH—N hydrogen-bonding system, with NN distances of 2.747 (7) Å.

The title compound, [Ni(C₁₄H₁₈N₄O₂)₂](NO₃)₂, the coordination environment of the metal centre is a slightly distorted octa­hedral, with the Ni atom linked to six N atoms. The Ni atom lies on a centre of symmetry.

In the title complex, [Pt(C₈H₆NO₂)Cl(C₈H₇NO₂)], the Pt^II centre is coordinated by a monodentate and an N,O-chelating deprotonated benzoyl­formaldehyde oxime and a Cl atom. There is an intra­molecular N—O⁻H—O hydrogen-bonding system between the oxime OH group and the oximate O atom.

In the title platinum(II) propiononitrile complex, [Ph₃PCH₂Ph][PtCl₃(EtCN)], the coordination polyhedron of the metal center is slightly distorted square planar.

The title Pt^IV complex, [PtCl₄(C₁₆H₂₈N₄O₆)] or trans-[PtCl₄{NH=C(Et)ON=C(Me)C(=O)OEt}₂], possesses a crystallographically imposed centre of symmetry. The coordination environment of the metal centre is a slightly distorted octa­hedron. An intra­molecular N—HN hydrogen bond between the imine H atom and the oxime N atom stabilizes the E configuration of the imine groups.