BINUCLEAR AND TETRANUCLEAR COMPLEXES PREPARED BY REACTIONS OF DODECACARBONYLTRIRUTHENIUM WITH THE N-SUBSTITUTED CINNAMIC ACID-AMIDES - CRYSTAL AND MOLECULAR-STRUCTURES OF [RU-2(MU-H)(MU-ETA(3)-PHC=CHC(O)N(CH2)(4)(CO)(6)] AND )-H)(2)(MU-ETA(3)-PHC=CHC(O)N(CH2)(4))(2)(CO)(10)]

The thermal reactions of Ru-3(CO)(12) with the N-substituted cinnamic acid amides PhCH=CHCONRR' (1) in hydrocarbons yield the binuclear and tetranuclear complexes, [Ru-2(mu-H)(mu-eta(3)-PhC=CHC(O)NRR') (CO)(6)] (2) and [Ru-4(mu(3)-H)(2)(mu-eta(3)-PhC=CHC(O) NRR')(CO)(10)] (3), in volving five-membered oxaruthenacycles eta(3) coordinated by the secon d ruthenium atom. The structures of the complexes were determined by s ingle crystal X-ray diffraction studies. On heating in hydrocarbons, c omplexes 2 are converted into clusters 3. The reverse transformation o ccurs on treatment of complexes 3 by methylene chloride. (C) 1998 Else vier Science S.A. All rights reserved.