Tetracyanonickelate(II) compounds of some (tetraazamacrocycle)nickel(II) cations. The structure of catena-Di(μ-cyano)dicyano(N-meso-5,7,7,12,14,14-hexamethy1-1,4,8,11-tetraazacyclotetradeca-1, 11-diene)dinicke1(II) hydrate

Abstract

Tetracyanonickelate(II) compounds of several (tetraazamacrocycle)nickel(II) cations have been prepared. The structure of the N-meso-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca- 4,11-diene, hmtd, compound [Ni(hmtd)Ni(CN)₄].H₂O has been determined by X-ray diffractometry [monoclinic, a 1780.3(3), b 1063.41(7), c 1409.3(2) pm, β 120.54(1)º, 24, space group C2/c, R 0.021, R_w 0.030 for 2178 reflections] and shows a chain polymeric structure with trans singlet ground state [Ni(CN)₄]^2- groups linking parallel stacked triplet ground state [Ni(hmtd)]²⁺ groups. The triplet ground state nickel(II) ions have a tetragonally elongated coordination environment [Ni-N (mean macrocycle) 204.5(1) pm, Ni-N (N≡C) 220.7(1) pm]. Tetracyanonickelate compounds of macrocycles related to hmtd but with different substituents, macrocycle ring size, and/or numbers of imine and amine donor groups were prepared. Some are diamagnetic, with discrete cation and anion, while others are similar to the hmtd compound, and for the latter, tetragonal distortions were evaluated from the reflectance spectra. Magnetic susceptibilities and infrared spectra are reported.