SYNTHESIS, STRUCTURE AND PROPERTIES OF BISALLYLTRIS(TRIMETHYLPHOSPHINE)MOLYBDENUM(II) X-RAY CRYSTAL-STRUCTURES OF [MO(ETA(1)ETA(2)-C3H5)(2)(PME3)(3)] AND PME4-)([MOCL4(PME3)(2)]()

Reaction of [MoCl2(PMe3)(4)] with two equivalents of allylmagnesiumbro mide yields the highly reactive bisallylmolybdenum compound [Mo(eta(1) eta(2)-C3H5)(2)(PMe3)(3)], (1). In addition to its X-ray structure an alysis its structure in solution is determined NMR spectroscopically. The Mo-C bonds are very sensitive to attack by compounds with slightly polar E-H bonds. This is exemplified in the reaction of 1 with CH2Cl2 generating propene, [MoCl4(PMe3)(3)], and PMe4Cl in the first steps. The latter two compounds further react to yield the phosphonium salt P Me4+[MoCl4(PMe3)(2)](-), (2). Treatment of 1 with two equivalents of C O results in C-C bond coupling so that 1,5-hexadiene in addition to [c is-Mo(CO)(2)(PMe3)(4)] can be isolated. (C) 1997 Elsevier Science S.A.