1,8-diphenylocta-1,3,5,7-tetraene complexes of ruthenium(II):: Crystal structures of [μ-(s-cis-1,2,3,4-η:s-cis,5,6,7,8-η-PhCH=CHCH=CHCH=CHCH=CHPh)(RuClCp*)2] and [μ-(s-trans-1,2,3,4-η:s-trans-5,6,7,8-η-PhCH=CHCH=CHCH=CHCH=CHPh){Ru(acac)2}2]

Reaction of 1,8-diphenyl-1,3,5,7-octatetraene with [Ru(mu Cl)Cp*](4) (1) (Cp* = eta(5)-pentamethylcyclopentadienyl) gave [mu(s-cis-1,2,3,4-eta:s-cis-5,6,7,8-eta-PhCH=CHCH-CHCH-CHCH-CHPh)(RuClCp*)(2)] (2), whose crystal structure revealed that 2 has a planar tetraene backbone coordinated by two Cp*RuCl moieties in s-cis-eta(4)-fashion; while the reaction with Ru(acac)(3)/Zn system resulted in the formation of [mu(s-trans-1,2,3,4-eta:s-trans-5,6,7,8-eta-PhCH=CHCH=CHCH=CHCH=CHPh){Ru(acac)(2)}(2)] (3), where both of the two Ru(acac)(2) moieties prefer s-trans coordination and thus the plane of the octatetraene backbone of 3 is deformed into an S-shape. Electrochemical studies for complexes 2 and 3 revealed that they have a coupling between the two ruthenium centers and are conjugatively interacted d pi-p pi organometallic systems.