The crystal and molecular structure of bis(2,2′-dipyridylamine- N, N′)di(nitrato- O)cadmium(II); Solid state 113Cd NMR, components and orientation of the chemical shift tensor relative to the donor ligands

Abstract

The structure of the titled compound has been determined and refined. The structure consists of isolated molecules separated by ordinary Van der Waals' distances. The Cd atom is on a crystallographic center of symmetry. The coordination polyhedron of the Cd atom is distorted octahedral with four pyridine nitrogen donors in the equatorial plane and with axial oxygen atoms from the nitrate groups. The CdO distance is 2.599(4) Å, the CdN distances are 2.310(4) and 2.316(3) Å, and the NCdN bite angle is 79.0(1)°. The solid state magic angle spinning/cross polarization 113Cd NMR isotropic chemical shift is +51.4 ppm and the components of the chemical shift tensor are: S 11= −92 ppm, S 33 = +208 ppm and S 22 = +39 ppm and their directions are: in the CdN 4 plane and bisecting the NCdN bite angle, perpendicular to the CdN 4 plane and the third perpendicular to the other two, respectively. This permits the assignment of contributions to the chemical shift tensor of 50 ppm from pyridine nitrogen and of −50 ppm from nitrate oxygen. From the tensor components, atomic nitrogen can be distinguished from aliphatic nitrogen donors. Crystal data: C 20H 18O 6N 8Cd; M r = 578.8, F(000) = 580, monoclinic, P2 1/ c, a = 8.591(1), b = 16.496(2), c = 7.878(1) Å, β = 95.97°, λ = 0.71073 Å, Mo Kα, V = 1110(1) Å 3. Z = 2, D m = 1.73(2), D x = 1.73 g/cm 3, μ = 10.3 cm −1, R f = 0.039, 1834 reflections, 160 parameters, T ∼ 298 K. Refinement was by full matrix least-squares with anisotropic temperature factors.