Si-H-functionalized ferriodisiloxanes: Synthesis from the ferriodimethylsilanols C5R5(OC)(2)Fe-SiMe2OH (R = H, Me) and photoinduced transformation into mu(2)-disiloxanediyl-bridged dinuclear iron complexes

Hydrolysis of the ferriochlorosilanes C5R5(OC)(2)Fe-SiMe2Cl [R = H (1a), Me (1b)] in the presence of Et3N yields the corresponding ferriosilanols C5R5(OC)(2)Fe-SiMe2(OH) (2a and 2b). In addition, 2b is also obtained by oxo-functionalization of C5Me5(OC)(2)Fe-SiMe2H (3) with dimethyldioxirane. The ferriosilanol 2a can be converted into the ferriodisiloxanes Cp(OC)(2)Fe-SiMe2OSiR3 [R3Si = Me-2(H)Si (5a), pTol(2)(H)Si (5b), Me3Si (5c) and pTol(Me)(H)Si (5d)] by condensation with the chloro(organo)silanes R3SiCl (4a-d). Irradiation of 5a and 5b results in CO elimination, followed by dimerization to give the cyclic 1,5-diferratetrasiloxanes [mu(2)-SiMe2OSi(R)(2)](2) [Fe(H)(CO)Cp](2) [R = Me (6a) and pTol (6b)]. Compounds 2b and 6b have been characterized by single-crystal X-ray structure determination. (C)Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.