Crystal and molecular structure of aquobis-(2,2′-bipyridyl)palladium dinitrate

Abstract

Crystals of the title compound are monoclinic with a= 6·932(1), b= 26·721(6), c= 11·697(3)Å, β= 103·4(1)°, space group P2₁/c, and Z= 4. The structure was determined from diffractometer data by Patterson and Fourier methods and refined by full-matrix least-squares techniques to R 0·060 for 2589 observed reflections. The structure consists of discrete Pd(bipy)₂²⁺ cations and nitrate anions. There is a weak interaction between the metal ion and one of the nitrate ions, the other nitrate ion being hydrogen bonded to a water molecule. The steric strain imposed by the interaction of interligand ortho-hydrogens is reduced by a distortion from a square planar configuration. The ‘bite’ of the 2,2′-bipyridyl ligand results in a rectangular distortion of the PdN₄ skeleton such that mean of the angles N–Pd–N, where both nitrogens are from the same ligand, is 80·0(3)°. The corresponding angle involving nitrogens from different ligands is 102·2(3)°. There is also a mutual twist of the two ligands to avoid interligand hydrogen contacts. The mean diagonal angle, N–Pd–N, is 164·5(5)°. The torsion angle is 24·3°