REACTIONS OF (PME(3))(4)RU(C2H4) AND (DMPE)(2)RU(C2H4) WITH WEAK PROTON-DONATING ELECTROPHILES HX (X=OAR, SAR, NHPH, PHPH) - SYNTHESIS OF COMPLEXES WITH METAL HETEROATOM SINGLE BONDS

Reactions of the ruthenium ethylene complexes (PMe(3))(4)Ru(C2H4) and (DMPE)(2)Ru(C2H4) with a variety of HX compounds (X = SAr, OAr, PPhH, NHPh and Ph) have been explored. In all cases; the tetrakis(trimethylphosphine) complex reacted to form ethylene and the hydride species, (PMe(3))(4)Ru(H)(X). However, parallel studies with the related material (DMPE)(2)Ru(C2H4) suggest that these complexes react as strained metallacycles toward HX. Thus, the bis(DMPE) analog gave the ethyl species (DMPE)(2)Ru(X)(CH2CH3) in its reactions with HSAr and PH(2)Ph, and thermolysis of these ethyl complexes led to the formation of the hydrides and free ethylene. The reaction of the DMPE ethylene complex with p-cresol allowed isolation of an intermediate cationic ethylene hydride species, but this was converted rapidly to the corresponding aryloxy hydride complex, even at room temperature. With NH(2)Ph the bis(DMPE) complex formed only the corresponding hydride species. In an attempt to generate an acetylene complex that similarly might react as a strained metallacyclopropene, (PMe(3))(4)Ru(CH=CH2)(2) was generated from the reaction of CH=CH2MgBr with (PMe(3))(4)RuCl2. However, thermolysis of the divinyl species led only to the formation of the butadiene complex, (PMe(3))(3)Ru(C4H6).