title: Synthesis and nonlinear optical absorption of novel porphyrin-osmium-cluster complexes.
abstract: Reaction of azido(tetra-p-tolylporphyrinato)indium(III) [TTPInN(3)] and [Os(3)(mu-H)(2)(CO)(10)] in toluene at 80 degrees C overnight gave two major products, complexes 1 and 2. Complex 1 had an axial bridge of "NH", while 2 had an axial bridge of "N" between the porphyrin and osmium cluster moieties. Complex 1 could be converted to 2 when refluxed in toluene. These two novel porphyrin-osmium clusters are the first axially linked porphyrin-metal cluster complexes. UV/Vis spectroscopy revealed the significant ground state electronic perturbation in the capped complex 2, demonstrating that the remarkable electronic interaction of the moieties within the molecule was achieved by this special structural arrangement. In addition, the electrochemistry of 1 and 2 were investigated and their oxidation current voltage curves are similar to those of indium(III)-porphyrins with a metal-metal sigma bond such as [TPPInRe(CO)(5)] (TPP=tetraphenylporphyrin). The two new molecules also exhibit large nonlinear optical absorption at 532 nm with a ns pulse laser and are potential optical limiting materials for sensor protection in the visible region.
authors.affiliation: DSO National Laboratories, 20 Science Park Drive, 118230 Singapore. yguoying@dso.org.sg
authors.forename: Guo Ying
authors.initials: GY
authors.lastname: Yang
authors.forename: Siau Gek
authors.initials: SG
authors.lastname: Ang
authors.forename: Leng Leng
authors.initials: LL
authors.lastname: Chng
authors.forename: Yiew Wang
authors.initials: YW
authors.lastname: Lee
authors.forename: Ernest Wei-Pin
authors.initials: EW
authors.lastname: Lau
authors.forename: Kin Seng
authors.initials: KS
authors.lastname: Lai
authors.forename: How Ghee
authors.initials: HG
authors.lastname: Ang