title: Homoleptic tetranuclear complexes of divalent tin and lead tetraolates.
abstract: Homoleptic tetranuclear complexes of divalent tin and lead tetraolates, M(4)(hfpt)(2) [M = Sn (1) and Pb (2); hfpt(4-) is an anion of 1,1,1,5,5,5-hexafluoropentane-2,2,4,4-tetraol], have been obtained in high yield from the corresponding (trimethylsilyl)amides. The solid-state structures of 1 and 2 contain discrete molecules in which a butterfly tetrahedron of metal atoms is sandwiched between two tetraolate ligands acting in tetradentate mode. The lone-pair Sn(2+) and Pb(2+) cations exhibit pyramidal coordination of four ligand oxygen atoms. A multinuclear NMR study unambiguously confirmed that metal tetraolates retain their polynuclear structure in solution of even coordinating solvents. An interesting example of the strong through-space coupling between (19)F of the tetraolate trifluoromethyl groups and (117/119)Sn or (207)Pb nuclei was found. Both compounds were shown to have clean, low-temperature decomposition that results in crystalline oxides SnO(2) and PbO, respectively, for 1 and 2. This work demonstrates the remarkable coordination properties of the tetraolate ligand that can be utilized for the preparation of a wide variety of poly- and heterometallic complexes. Decomposition studies revealed a great potential of metal tetraolate complexes as prospective molecular precursors for the soft chemistry approach to oxide materials.
authors: Department of Chemistry, University at Albany, SUNY, Albany, New York 12222, USA.
authors: Zheng
authors: Z
authors: Wei
authors: Jen-Hsien
authors: JH
authors: Yang
authors: Volodimir D
authors: VD
authors: Vreshch
authors: Alexander V
authors: AV
authors: Zabula
authors: Alexander S
authors: AS
authors: Filatov
authors: Evgeny V
authors: EV
authors: Dikarev