Reactions of small boranes with ruthenium phosphine hydrides: Oligomerisation of monoborane-tetrahydrofuran to a nido-hexaruthenaborane

Reaction of [Ru(PPh3)4H2] with BH3 · thf at room temperature gives borane oligomerisation with the formation of nido-2-[Ru(PPh3)2(H)B5H10] (1). This cluster is also formed by reaction of [Ru(PPh3)4H2] with nido-B5H9. In contrast to [Ru(PPh3)4H2] reaction of [cis-Ru(PMe3)4H2] with excess BH3 · thf gives nido-2-[Ru(PMe3)3B4H8] (3). Reaction of [cis-Ru(PMe3)4H2] with nido-B5H9 also gives (3) and nido-2-[Ru(PMe3)3B9H13] (4).