The formation of #sigma#-phenylethynyl and #sigma#-diphenylbutenynyl complexes in the reaction of #sigma#-alkenyl ruthenium(II) complexes with phenylacetylene. The X-ray structure of a ruthenium(II) complex containing a #sigma#-phenylethynyl ligand

摘要

Ruthenium(II) complexes containing both #sigma#-alkenyl and #eta#~2-carboxylate ligands Ru(O_2CR~2)(CHCHR~1)(CO)(PPh_3)_2(R~1=~tBu,Ph;R~2=CH=CHCH=CHCH_3) react with phenylacetylene in two stages.Their reaction with an equivalent amount of the alkyne led to the formation of a #sigma#-alkynyl-containing ruthenium(II) complex Ru(O_2CR~2)(C ident to CPH)(CO)(PPh_3)_2(R~1=~tBu,Ph;R~2=CH=CHCH=CHCH_3),the molecular structure of which was established by X-ray diffraxction.This #sigma#-alkynyl complex then reacts with phenylacetylene to form a #sigma#-butenynylcontaining compound Ru(O_2CR~2)(C(C ident to CPh)=CPhH)(CO)(PPh_3)_2(R~2=CH=CHCH=CHCH_3).Both reactions support the key rode of alkynyl ligands in the dimerization of alkynes.