Cyanide-bridged polynuclear complexes

The three mixed valent dinuclear cyanide-bridged complexes LMCNFeCl3, (LM = Cp(dppe)Fe, Cp(dppe)Ru and Cp(PPh3)2Ru) were synthesized and characterized by X-ray single crystal determination, IR, UV-Vis and cyclic voltammograms, respectively. The three mixed valent dinuclear complexes display metal- metal charge transfer (MMCT) bands in the visible region. Some of MMCT properties in the complexes have been analyzed. The cyanide-bridged trans and cis trinuclear complexes with a M’-CN-M-NC-M’ framwork were synthesized and determined by IR, UV-Vis and cyclic voltammograms, respectively. The mixed valent trinuclear coplexes [Cp(dppe)FeIINCRuII(L)4CNFeIII(dppe)Cp]3+ were prepared. MMCT absorptions were observed in the UV-Vis-NIR spectra of the mixed valent trinuclear coplexes. The analysis of the Hush theory for the complexes suggests that they are typical class II mixed valent species. The mechanism of the MMCT in the mixed valent complexes has been analyzed. Two hexanuclear cyanide bridged complexes [(Cp(dppe)FeCN)2{Fe2(OR)2(NO3)2}(NCFe(dppe)Cp)2](PF6)2 (R = CH3, C2H5) were synthesized. Complex [(Cp(dppe)FeCN)2{Fe2(OCH3)2(NO3)2}(NCFe(dppe)Cp)2](PF6)2 was structurally characterized. In the two hexanuclear complexes, as expected, there exists a metal-metal charge transfer resulting from electron transitions from the terminal Cp(dppe)Fe units to the central [Fe2(OR)2] core. A series of heptanuclear complex [LMCN)Ni5(tpda)4(NCML)]2+ / 0 (LM = Cp(dppe)Fe, Cp(PPh3)2Ru, (CO)5Mo, (CO)5W and Cp(CO)2Fe) were synthesized and characterized by IR, UV-Vis and cyclic voltammogramms. Complex [Cp(dppe)FeCNNi5(tpda)4NCFe(dppe)Cp](PF6)2 was structurally characterized. The cyclic voltammogramms and the UV-Vis spectra indicate that no long range metal-metal interaction exists in any of the heptanuclear complexes.

Author dc:creator

• Sheng, Tianlu

Contributors dc:contributor

• Vahrenkamp, Heinrich

• Cyanidverbrückte Komplexe
• Gemischtvalenten Komplexe
• Metal-Metal-Charge-Transfers (MMCT)
• Metall-Metall-Wechselwirkungen
• Cyanide-Bridged
• Mixed valent complexes
• Polynuclear complexes
• Metal-metal charge transfer (MMCT)
• Metal-Metal interactions

Repository record source_url

https://freidok.uni-freiburg.de/data/652

OAI identifier oai:identifier

oai:freidok.uni-freiburg.de:652