title: pH-Dependent spectroscopic and luminescent properties, and metal-ion recognition studies of Re(I) complexes containing 2-(2'-pyridyl)benzimidazole and 2-(2'-pyridyl)benzimidazolate.
abstract: A series of Re(I) complexes, [Re(CO)(3)Cl(HPB)] (1), [Re(CO)(3)(PB)H(2)O] (2), [Re(CO)(3)(NO(3))(PB-AuPPh(3))] (3), and [Re(CO)(3)(NO(3))(PB)Au(dppm-H)Au](2) (4) [HPB = 2-(2'-pyridyl)benzimidazole; dppm = 2,2'-bis(diphenylphosphinomethane)], have been synthesized and characterized by X-ray diffraction. Complex 1, which exhibits interesting pH-dependent spectroscopic and luminescent properties, was prepared by reacting Re(CO)(5)Cl with an equimolar amount of 2-(2'-pyridyl)benzimidazole. The imidazole unit in complex 1 can be deprotonated to form the imidazolate unit to give complex 2. Addition of 1 equiv of AuPPh(3)(NO(3)) to complex 2 led to the formation of a heteronuclear complex 3. Addition of a half an equivalent of dppm(Au(NO(3)))(2) to complex 2 yielded 4. In both 3 and 4, the imidazolate unit acts as a multinuclear bridging ligand. Complex 4 is a rare and remarkable example of a Re(2)Au(4) aggregate in combination with μ(3)-bridging 2-(2'-pyridyl)benzimidazolate. Finally, complex 2 has been used to examine the Hg(2+)-recognition event among group 12 metal ions. Its reversibility and selectivity toward Hg(2+) are also examined.
authors: Department of Chemistry and Biochemistry, National Chung Cheng University, 168 University Road, Min-Hsiung, Chiayi 62102, Taiwan. chebct@ccu.edu.tw
authors: Biing-Chiau
authors: BC
authors: Tzeng
authors: Bo-So
authors: BS
authors: Chen
authors: Chang-Kai
authors: CK
authors: Chen
authors: Yuan-Ping
authors: YP
authors: Chang
authors: Wen-Chian
authors: WC
authors: Tzeng
authors: Tsung-Yi
authors: TY
authors: Lin
authors: Gene-Hsiang
authors: GH
authors: Lee
authors: Pi-Tai
authors: PT
authors: Chou
authors: Yu-Jie
authors: YJ
authors: Fu
authors: A Hsiu-Hua
authors: AH
authors: Chang