title: Reactivity of aqua coordinated monoporphyrinate lanthanide complexes: synthetic, structural and photoluminescent studies of lanthanide porphyrinate dimers.
abstract: Dimerization of monoporphyrinate lanthanide complexes [Yb(Por)(H(2)O)(3)]Cl, (Por = TTP(2-), TMPP(2-) and TPP(2-)) in the presence of sterically hindered tripodal ligand, zinc Schiff-base, dilute HCl, K(2)CO(3) solution, 4,4'-bipyridine (bipy), and basic 8-hydroxyquinaldine (HQ) solution was observed in CH(2)Cl(2) at room temperature. Six neutral dimeric lanthanide porphyrinate complexes, [Yb(TTP)(mu-OH)](2)(mu-THF) (1), [Yb(TMPP)(mu-OH)(H(2)O)](2) (2), [Yb(TPP)(mu-OH)(mu-H(2)O)](2) (4), [Yb(TMPP)(mu-Cl)(H(2)O)](2) (5), [Yb(TMPP)(mu-OH)](2)(THF) (6) and [Yb(TPP)](2)(mu-OH)(mu-Q) (7), were obtained. X-Ray diffraction studies showed that for the dimers, the two lanthanide ions were bridged by OH(-), Cl(-) or H(2)O. Photoluminescent studies showed that the porphyrinate dianion acted as an antenna, transferred its absorbed visible energy to the lanthanide ion and enabled the latter emitting in the near-infrared (NIR) region. In general, the NIR emission is more intense for the dimers than for the monomers, and the NIR emission intensity decreases as the number of O-H oscillators present in the molecule increases.
authors.affiliation: Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong, P.R. China.
authors.forename: Hongshan
authors.initials: H
authors.lastname: He
authors.forename: Xunjin
authors.initials: X
authors.lastname: Zhu
authors.forename: Anxin
authors.initials: A
authors.lastname: Hou
authors.forename: Jianping
authors.initials: J
authors.lastname: Guo
authors.forename: Wai-Kwok
authors.initials: WK
authors.lastname: Wong
authors.forename: Wai-Yeung
authors.initials: WY
authors.lastname: Wong
authors.forename: King-Fai
authors.initials: KF
authors.lastname: Li
authors.forename: Kok-Wai
authors.initials: KW
authors.lastname: Cheah