REACTIONS OF 1,4-DIFERROCENYLBUTA-1,3-DIYNE AND 1,4-DIPHENYLBUT-1-EN-3-YNE WITH RU-3(CO)(12) - CRYSTAL-STRUCTURE OF ETA(1)-ETA(1)-ETA(4)-ETA(2)-C(4)PH(2)(CH=CHPH)(2))

Diyne FcC=CC=CFc (Fc is ferrocenyl) reacts with RU(3)(CO)(12) in boili ng hexane to yield binuclear complexes Ru-2(CO)(6){C(4)Fc(2)(C=CFc)(2) } and Ru-2(CO)(6){C(4)Fc(2)(C=CFc)(2)C=O} containing ruthenacyclopenta diene and diruthenacycloheptadienone rings, respectively. The isomeris m of the complexes is due to the different ways of coupling of the alk yne fragments of the diyne, namely, ''head-to-head'', ''head-to-tail'' or ''tail-to-tail''. The reaction of enyne PhC=CCH=CHPh with RU(3)(CO )(12) under similar conditions gives isomeric binuclear complexes Ru-2 (CO)(6){C(4)Ph(2)(CH=CHPh)(2)} and trinuclear clusters Ru-3(CO)(6)(mu- CO)(2){C(4)Ph(2)(CH=CHPh)(2)} and ta(1)-eta(1)-eta(4)-eta(2)-C(4)Ph(2) (CH=CHPh)(2)}. The structure of the latter was determined by X-ray dif fraction analysis. The Ru-3 triangle coordinates eight terminal CO gro ups and the organic ligand resulting from ''head-to-head'' dimerizatio n of enyne molecules; the ruthenacyclopentadiene moiety is eta(4)-coor dinated to the Ru(CO)(2) group, and the third ruthenium atom is eta(2) -bound to one of the PhCH=CH groups.