Mp. Suh et al., PROPERTIES AND CRYSTAL-STRUCTURE OF A 4-CO-ORDINATE NICKEL(I) COMPLEXWITH THE MACROTRICYCLE 1,3,6,8,12,15-HEXAAZATRICYCLO[L3.3.1.1 (8,12)]ICOSANE, Journal of the Chemical Society. Dalton transactions, (10), 1995, pp. 1577-1581
The four-co-ordinate nickel(I) macrocyclic complex R,R,S,S-[NiL]ClO4 (
L = 6.8,12,15-hexaazatri-cyclo[13.3.1.1(8.12)]icosane) has been synthe
sized by the reduction of the corresponding nickel(II) complex R,R,S,S
,-[Nil][ClO4](2) . 0.5H(2)O with sodium amalgam in MeCN under nitrogen
. It absorbs at 589 (epsilon = 620) and 355 nm (epsilon = 3020 dm(3) m
ol(-1) cm(-1)). The EPR powder spectrum shows the anisotropic axial g
values of g(parallel to) = 2.272 and g(perpendicular to) = 2.074. The
complex crystallizes in the orthorhombic space group P2(1)2(1)2(1) wit
h a = 8.681(2), b = 11.358(2), c = 19.146(4) Angstrom and Z = 4. The s
tructure was solved by the heavy-atom method and refined anisotropical
ly to R = 0.0363 and R' = 0.0379 for 1551 observed reflections [I > 3
sigma(I)] measured with Mo-K alpha radiation. It reveals a tetrahedral
ly distorted square-planar geometry having two sets of Ni-N bond dista
nces, three at 1.978(3) (average) and one at 1.878(4) Angstrom, withou
t any noticeable expansion of the macrocyclic hole.