Syntheses and reactions of ruthenium complexes containing C6 and C8 chains

Reactions of {Cp(Ph3P)(2)Ru}(2){mu-(C drop C)(n)} (n = 3, 4) with C-2(CN)(4), dicobalt carbonyls and Fe-2(CO)(9) are described. For n = 3, the central C drop C triple bond is attacked by the metal carbonyls, giving {Ru(PPh3)(2)Cp}(2){mu-C=CC2[Co-2(CO)(6)]C drop C} (4), {Ru(PPh3)(2)Cp}(2){mu-C drop CC2[Co-2(mu-dppm)(CO)(4)]C drop C} (5) and Fe-3{mu(3)CC drop C[Ru(PPh3)(2)Cp]}(2)(CO)(9) (7). For n = 4, the first bis-ad-duct with tcne is described, while the metal carbonyls gave {Ru(PPh3)(2)Cp}(2)[mu-dppm)(CO)(4)]C drop CC drop C} (6) and Fe-3{mu(3)-CC drop C[Ru(PPh3)(2)Cp]} {mu(3)-CC drop CC drop C[Ru(PPh3)(2)Cp]}(CO)(9) (8). While the usual bending of the carbon chain is found in the dicobalt complexes, reactions with the iron carbonyl result in cleavage of a C drop C triple bond to give CFe3C clusters. The molecular structures of 4 and 7 have been determined. (C) 2000 Elsevier Science S.A. All rights reserved.