A fluorescent bis(benzoxazole) ligand: Toward binuclear Zn(II)-Zn(II) assembly

作者：Chu Qinghui; Medvetz Doug A; Panzner Matthew J; Pang Yi^*

来源：Dalton Transactions, 2010, 39(22): 5254-5259.

DOI：10.1039/c000989j

A bis(benzoxazole) ligand (HL) has been synthesized, and its reaction with Zn(OAc)(2) has led to fluorescent complexes via formation of binuclear Zn(II)- Zn(II) cores. The ligand-to-metal ratio of the complexes varies from 1 : 1 to 2 : 1, depending on the reaction conditions. A large binding constant K = 8.3 x 10(20) [M(-3)] has been determined for the reaction L + Zn(2+) -> L(2):Zn(2)(2+). The result indicates that the bis(benzoxazole) ligand is a useful building block to construct a binuclear core. On the basis of X-ray analysis, the binuclear Zn(II)-Zn(II) distance in the complexes is determined to be similar to 3.22 angstrom, which is quite comparable to that found in the enzymes (3.3 angstrom). Absorption and fluorescence study shows that a subtle chemical environmental change within the binuclear core can induce a large optical response.

• 出版日期2010