UNUSUAL COORDINATION OF TRIPODAL NN3S3 DONOR LIGAND WITH NICKEL(II) -SINGLE-CRYSTAL X-RAY STRUCTURE OF H2CH2N(CH2CH2N=CH(C4H3S))(2))(CH3CN)(H2O)](PF6)(2)
A. Das et al., UNUSUAL COORDINATION OF TRIPODAL NN3S3 DONOR LIGAND WITH NICKEL(II) -SINGLE-CRYSTAL X-RAY STRUCTURE OF H2CH2N(CH2CH2N=CH(C4H3S))(2))(CH3CN)(H2O)](PF6)(2), Polyhedron, 14(4), 1995, pp. 495-499
Reaction of Ni(acetate)(2).6H(2)O with a potentially heptentate Schiff
base ligand, tris[4-(2-thienyl)-3-aza-3-butenyl]amine [(thiophene),tr
en], resulted in the formation of an unexpected octahedral Ni-II compl
ex with an NiN4 core and the remaining two coordination sites occupied
by solvent molecules; An X-ray crystal structure of the complex estab
lished the unusual cleavage at one of the three alpha-imino bonds and
revealed that it deviates from the usual mono-capped trigonal prismati
c coordination polyhedron designed for this type of complex. The compl
ex molecule has an approximate plane of symmetry(C-s) rather than the
three-fold axis (C-3) normally observed for this type of complex and i
s the first example where the apical 'unique' nitrogen approaches the
Ni-II as closely as the other three nitrogens of the ligand.