Ni(L)2complexes, where L equals 2-(trifluoroacetyl) heteroaromatic anion have been prepared and characterized. 2-(Trifluoroacetyl)-picolinato anion (TFAP) gives a Ni(L)2complex that appears to be a dimeric 5-coordinate square pyramid. The complexes Ni(4MeTFAP)2 and Ni(5MeTFAP)2are square planar complexes while Ni(6Me-TFAP)2is tetrahedral due to steric interference. In non-donor solvents, the complexes Ni(TFAP)2, Ni(4MeTFAP)2 and Ni(5MeTFAP)2 exhibit properties that indicate a polymer/monomer equilibrium. Ni(L)2complexes undergo a unique gas-solid dissociation reaction with H2 O and NH3 to give coordinated NH2“ and OH”. © 1979, Taylor & Francis Group, LLC. All rights reserved.