Ruthenocenophanes

Abstract

The new dinuclear [1.1]metallocenophanes, bis(dimethylsila)-[1.1]ferrocenophane (2a) and bis(dimethylsila)-[1.1]ruthenocenophane (2b), were synthesized by the reaction of dilithium di(cyclopentadienyl)dimethylsilane with FeCL·2 thf and RuCl2·4 dmso in tetrahydrofuran solution, and compared with the known bis(methylene)-bridged analogues [1.1]ferrocenophane (8a) and [1.1]ruthenocenophane (8b), respectively. A series of mononuclear [n]ruthenocenophanes including 1,1,2,2 -tetramethyl-[2]ruthenocenophane (10b), 1,2 - bis(dimethylsila)-[2]ruthenocenophane (3b), 1,3-bis(dimethylsila)-2-oxa-[3]ruthenocenophane (4b) and 1,4-bis(dimethylsila)-[4]ruthenocenophane (5b) was also prepared and studied together with the corresponding [n]ferrocenophanes, 10a and 3a-5a. 1,1′-Dilithioruthenocene was found to be a versatile starting material for the synthesis of silicon-substituted ruthenocene derivates such as Ru(C5H4-R)2 (R = SiMe3 (6b), Si2Me5 (7b)) and [n]ruthenocenophanes (3b- 5b). A complete set of 1H, 13C and 29Si NMR data is presented, and the available structural data are discussed with respect to the tilt angle a of the cyclopentadienyl ring ligands which is larger in the more strained [2]ruthenocenophanes than in the corresponding [2]ferrocenophanes.