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)�,
24, space group C2/c, R 0.021, Rw 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.