Studies of New Nickel(II) Complexes with Bridging Ligands

Abstract

Five new nickel(II) complexes with the composition {[Ni(L1)(1,4-chdc)]∙4H₂O}_(n) (1), {[Ni(L1)(1,1'-fdc)]∙3H₂O}_(n) (2), catena-(μ-WO_(4)-O,O')[Ni(L1)]∙3H₂O (3), {[Ni(dipic)(μ-dipic)Ni(L2)]}_(n) (4), catena-(μ-WO_(4)-O,O')[Ni(L2)]∙5H₂O (5) (L1 = 1,4,8,11-tetraazacyclotetradecane, cyclam, L2 = 1,8-dihydroxylethyl-1,3,6,8,10,13-hexaazacyclotetradecane, 1,4-chdc = 1,4-cyclohexanedicarboxylate, 1,1'-fdc = 1,1'-ferrocenedicarboxylate, dipic = 2,6-pyridinedicarboxylate, dipicolinate) have been synthesized and structurally characterized by a combination of analytical, spectroscopic and X-ray diffraction methods. In 1-5, all the complexes exhibit novel one-dimensional polymeric structures with nickel(II) centers and bridging ligands. And the macrocycles and the axial ligands are highly involved in multiple types of hydrogen bonding interactions, resulting in stabilization.