Tuning the Spin Ground State in Heterononanuclear Nickel(II)−Copper(II) Cylinders with a Triangular Metallacyclophane Core

3 páginas, 2 figuras, 1 gráfico.-- et al.Two new heterometallic NiIInCuII(9−n) complexes [n = 1 (2) and 2 (3)] have been synthesized following a multicomponent self-assembly process from a n:(3 − n):2:6 stoichiometric mixture of Ni2+, Cu2+, L6−, and [CuL′]2+, where L and L′ are the bridging and blocking ligands 1,3,5-benzenetris(oxamate) and N,N,N′,N′′,N′′-pentamethyldiethylenetriamine, respectively. Complexes 2 and 3 possess a unique cyclindrical architecture formed by three oxamato-bridged trinuclear linear units connected through two 1,3,5-substituted benzenetris(amidate) bridges, giving a triangular metallacyclophane core. They behave as a ferromagnetically coupled trimer of two (2)/one (3) S = 1/2 CuII3 plus one (2)/two (3) S = 0 NiIICuII2 linear units with overall S = 1 NiIICuII8 (2) and S = 1/2 NiII2CuII7 (3) ground states.This work was supported by the MICINN (Spain) (Projects CTQ2007-61690, MAT2007- 60660, CSD2007-00010, and CSD2006-00015), the Generalitat Valenciana (Spain) (Project PROMETEO/2009/ 108), the Gobierno Aut onomo de Canarias (Spain) (Project PI2002/175), the MESR and CNRS (France). M.-C.D. and J.F.-S. thank the MESR and Generalitat Valenciana, respectively, for doctoral grants. E.P. acknowledges the MICINN for a postdoctoral (“Juan de la Cierva”) grant.Peer reviewe