Hexane-1,6-diammonium dinitrate.

The hexane-1,6-diammonium cation of the title compound, C(6)H(18)N(2) (2+)·2NO(3) (-), lies across a crystallographic inversion centre and shows significant deviation from planarity in the hydro-carbon chain. This is evident from the torsion angle of -64.0°(2) along the N-C-C-C bond and thse torsion angle of -67.

trans-Dichloridobis[tris-(4-methoxy-phen-yl)phosphine]palladium(II) benzene monosolvate.

The structure of the title compound, [PdCl(2)(C(21)H(21)O(3)P)(2)]·C(6)H(6), shows a square-planar geometry for the Pd(II) atom within a Cl(2)[P(PhOMe)(3)](2) ligand set. The crystal structure contains benzene as solvent. The Pd(II) atom sits on a centre of inversion and therefore the asymmetric unit contains the Pd(II) atom, one Cl atom, one tris-(4-methoxy-phen-yl)phosphine ligand and one half of the benzene solvent mol-ecule.

trans-Dichloridobis[tris-(2-methoxy-phen-yl)phosphine]palladium(II).

The structure of the title compound, [PdCl(2)(C(21)H(21)O(3)P)(2)], shows a nearly square-planar geometry for the Pd(II) atom within the Cl(2)Pd[P(PhOMe)(3)](2) ligand set. The Pd(II) atom sits on a centre of inversion and therefore the asymmetric unit contains one half-mol-ecule, i.e.

trans-Bis[bis-(2-methoxy-phen-yl)phenyl-phosphine-κP]dichloridopalladium(II).

The structure of the title compound, [PdCl(2)(C(20)H(19)O(2)P)(2)], shows a square-planar geometry for the Pd(II) ion within a Cl(2)Pd[PPh(PhOMe)(2)](2) ligand set. The Pd(II) atom sits on an inversion centre and therefore the asymmetric unit contains the Pd(II) atom, one Cl atom and one bis-(2-methoxy-phen-yl)phenyl-phosphine ligand. The trans arrangement of ligands is also imposed by symmetry.

Hydrogen-bonding motifs and thermotropic polymorphism in redetermined halide salts of hexamethylenediamine.

The redetermined crystal structures of hexane-1,6-diammonium dichloride, C(6)H(18)N(2)(2+) x 2 Cl(-), (I), hexane-1,6-diammonium dibromide, C(6)H(18)N(2)(2+) x 2 Br(-), (II), and hexane-1,6-diammonium diiodide, C(6)H(18)N(2)(2+) x 2 I(-), (III), are described, focusing on their hydrogen-bonding motifs. The chloride and bromide salts are isomorphous, with both demonstrating a small deviation from planarity [173.89 (10) and 173.