Synthesis, structure, and reactions of a bimetallacyclic carbene complex of ruthenium, cyclo-

Article abstract of DOI:10.1016/0022-328X(90)80239-V

Reaction of Ru(CF3)Br(CO)2(PPh3)2 with an excess of BBr3 produces a red salt identified as .Upon standing this solid loses CO and BBr3, to form , A, the structure which has been determined by X-ray diffraction.The geometry about ruthenium is approximately octahedral, with the two phosphorus atoms of the tridentate bisphosphinocarbene ligand mutually trans, a one bromide trans to the carbene carbon.The other bromide and the carbonyl ligand are statistically interchanged about a crystallographic diad axis which passes through the carbene carbon,the ruthenium, and the trans bromide.The Ru-P distance is 2.353(2) Angstroem, the Ru-Br distances are 2.638(2) Angstroem (trans to carbene) and 2.537(2) Angstroem (trans to CO), and the Ru=C(carbene)distance is 1.941(12) Angstroem.Bromide is removed from compound A by treatment with AgSbF6 in MeCN to give , and this when treated with CO gives .The dicarbonyl cation reacts with NaBH4 to give , and with HNEt2 to give .