Synthesis, characterization and molecular structures of some tetraosmium carbonyl clusters containing pyridine or phenanthroline type ligands

The reactions of activated tetraosmium carbonyl cluster [Os-4(mu-H)(4)(CO)( 11)(NCMe)] 1 with monopyridyl ligands give new clusters [Os-4(mu-H)(4)(CO)( 11)(pyp)] 3 and [Os-4(mu-H)(4) (CO)(11)(pya)] 4. Similarly, the reactions o f [Os-4(mu-H)(4)(CO)(10)(NCMe)(2)] 2 with bipyridyl or phenanthroline type ligands afford [Os-4(mu-H)(4)(CO)(10)(bpy)] 5, [Os-4(mu-H)(4) (CO)(10)(dpbp y)] 6, [Os-4(mu-H)(4)(CO)(10)(phen)] 7, [Os-4(mu-H)(4)(CO)(10)(dmdpp)] 8, a nd [Os-4(mu-H)(4)(CO)(10)(dppz)] 9, which exhibit interesting ring conforma tions. Treatment of 2 with nitrogen-phosphorus mixed donor ligand gives a n ovel bridging cluster [Os-4(mu-H)(4)(CO)(10)(dpppy)] 10. (C) 1999 Elsevier Science S.A. All rights reserved.