Ferrocene Containing Trimethylsilyl Chalcogenides: Reagents for the Preparation of Functionalized Metal-Chalcogen Nanoclusters.

摘要

The preparation of silylated ferrocenoyl chalcogen reagents FcC{O}ESiMe3 (E = S 1a, Se 1b, Te, 1c) in good yield is presented. The reactions of these reagents with group 11 acetate salts stabilized by triphenylphosphine ligands has afforded the cluster complexes [Cu(S{O}CFc)(PPh3)2], 2 ; [Cu2(Se{O}CFc)2(PPh3)3], 3; and [M4(E{O}CFc)4(PPh3)4] (M = Cu, E = Se, 4; M = Ag, E = Se, 5, E = S, 6) in good yield. X-ray crystallographic characterization revealed that these complexes exhibit bridging ferrocenoylligands, with the exception of 2. Maintaining low temperatures throughout the reactions combined with control of crystallization temperatures was found to be an important factor when synthesizing the copper selenolate complexes. The electronic absorption spectra are presented and the cyclic voltammetry of the complexes is discussed.;Keywords: Ferrocene, ferrocenyl, nanocluster, nanoparticle, chalcogen, chalcogenolate, chalcogenide, X-ray crystallography, cyclic voltammetry, anion recognition, oxo-anions, silylated reagents, polyferrocenyl, group 11, group 16.;Previous work describing the electrochemistry of ferrocenyl functionalized metal chalcogen clusters has indicated a decomposition of the clusters upon oxidation of the ferrocenylligands. However, the incorporation of an "insulating" alkyl bridge between the ferrocenyl moiety and the chalcogen has since been shown to prevent this decomposition from occurring, thus the reagents FcC{O}OCH 2CH2SSiMe3 8b, FcC{O}OCH2CHSeSiMe 3 9b, FcC{O}NHCH2CH2SSiMe3 14b were prepared. Using reagents 8b and 14b, the monomeric complexes [Zn(N,N,N',N'-tmeda)(SCH2CH 2O{O}CFc)2] 15 and [Zn(N,N,N',N'-tmeda)(SCH 2CH2HN{O}CFc)2]16 were prepared. Furthermore, addition of reagents 8b and 9b to triphenylphosphine solubilized silver acetate yielded the polynuclear clusters [Ag14S(SCH 2-CH2O{O}CFc)12(PPh3)6 17 and [Ag7Br(SeCH2O{O}CFc)6(dppe) 3] 20. Cluster 17 displayed instability in solution which resulted in the formation of the polymeric [Ag8(ECH 2CH2O{O}CFc)8]n 18. The "insulating" nature of the alkyl bridge provides access to functionalized clusters which do not decompose upon oxidation of the ferrocenyl moieties. The addition of E(SiMe3)2 to reaction mixtures of FcC{O}OCH 2CH2ESiMe3 (E = S, Se) and Ph3PAgOAc affords larger polynuclear nanoparticles, 21-24, while still maintaining a FcC{O}OCH2CH2-- rich surface. These polyferrocenyl assemblies displayed a single redox wave in cyclic voltammograms making them ideal candidates for anion recognition studies. Additionally, particle composition, electronic absorption and oxo-anion recognition studies are discussed.