SYNTHESIS, CRYSTAL-STRUCTURE AND SOME REACTIONS OF THE RUTHENACARBORANE COMPLEX [RU(CO)(2)(MECCPH)(ETA(5)-7,8-C2B9H11]

The alkyne complex [Ru(CO)(2)(MeC=CPh)(eta(5)-7,8-C2B9H11] (3c) has be en prepared and its structure determined by X-ray crystallography. The ruthenium is co-ordinated on one side by the nido-7,8-C2B9H11 fragmen t in a pentahapto manner, and on the other by the two CO molecules and the alkyne [Ru-C-av. = 2.305, C-C = 1.228(3) Angstrom. Treatment of 3 c with PEt3 and Ph2PCH2PPh2 in CH2Cl2 affords the ylid complexes [Ru{C (Me)=C(Ph)PEt3} (CO)(2)(eta(5)-7,8-C2B9H11)] (4b) and [Ru{C(Me)=C(Ph)P (Ph)(2)CH2PPh2} (CO)(2)(eta(5)-7,8-C2B9H11)] (4c), respectively. The s tructure of 4b was established by an X-ray diffraction study which rev ealed that the PEt3 molecule was attached to the carbon atom of the CP h group. In contrast, reactions between 3e and the donor molecules AsP h3, SbPh3 and Ph2P(S)CH2P(S)Ph-2 resulted in displacement of the alkyn e and formation of the complexes [Ru(CO)(2)(L)(eta(5)-7,8-C2B9H11)] (5 a, L = AsPh3; 5b, L = SbPh3; 5c, L = Ph2P(S)CH2P(S)Ph-2). Treatment of 4c with the Ru(CO)(2)(eta(5)-7,8-C2B9H11) fragment yielded the diruth enium complex u-2(mu-Ph2PCH2PPh2)(CO)(4)(eta(5)-7,8-C2B9H11)(2)] (6). The structure, based on the linking of two Ru(CO)(2)(eta(5)-7,8-C2B9H1 1) groups by the ligand Ph2PCH2PPh2, was determined by X-ray crystallo graphy. NMR data for the new complexes are reported. (C) 1998 Elsevier Science S.A. All rights reserved.