COORDINATION CHEMISTRY OF PERHALOGENATED CYCLOPENTADIENES AND ALKYNES- SYNTHESIS OF DINUCLEAR RING-BRIDGED CYMANTRENES WITH -SIME2-BRIDGESOR -TICP2-BRIDGES - STRUCTURES OF [(OC)3MN(C5BR4-)]2SIME2 AND [(OC)3MN(C5CL4-)]2TICP2

[C5Br5]Mn(CO)3 reacts with butyl lithium and one equivalent of SiMe2Cl 2 to yield [C5Br4SiMe2Cl]Mn(CO)3 (1). The reaction of 1 with [C5X4Li]M n(CO)3 (X=Br, Cl) gives the bimetallic compounds (OC)3Mn(C5Br4-SiMe-C5 X4)Mn(CO)3 (X=Br (2), Cl (3)). 2 can also be obtained by reaction of t wo equivalents of [C5Br4Li]-Mn(CO)3 With one equivalent of SiMe2Cl2. [ C5Cl4Li]Mn(CO)3 reacts With Cp2TiCl2, depending on the reaction condit ions, to yield the bi- and trimetallic compounds [C5Cl4TiCP2Cl]Mn(CO)3 (4) and (OC)3Mn(C5Cl4-TiCp2-C5Cl4)Mn(CO)3 (5). The molecular structur es of 2 and 5 have been determined by X-ray crystallography.