Intramolecular ether oxygen coordination in the zinc complexes with dipicolylamine (DPA)-derived ligands
摘要:
The ether oxygen coordination to the zinc center in the complexes with dipicolylamine (DPA)-derived ligands, N-(2-methoxyethyl)-N, N-bis(2-pyridylmethyl) amine (L), N-(3-methoxypropyl)-N, N-bis(2-pyridylmethyl) amine (L'), and N-{3-(2-pyridylmethyloxy)propyl}-N, N-bis(2-pyridylmethyl) amine (L-Py) has been discussed. Upon chelation of the oxygen atom, L forms a five-membered chelate ring with respect to the 2-aminoethyl ether moiety whereas L' forms a six-membered chelate in 3-aminopropyl ether unit. This difference was highlighted by the crystal structures of ZnCl2 complexes, in which [Zn(L)Cl-2] (1) exhibited ether oxygen coordination but [Zn(L')Cl-2] (2) had the ether oxygen non-coordinated. The terminal pyridyl group of L-Py facilitates the ether oxygen atom coordination via a metal binding from the basal plane trans to the aliphatic nitrogen. (C) 2011 Elsevier B. V. All rights reserved.