(η⁵-C₅H₅)Ru(PPh₃)H₃: a stable ruthenium (IV) trihydride

Abstract

Reduction of ( q5-C5H5) R u ( P P ~~) ~C I(2) with LiAIH4 in tetrahydrofuran leads to the trihydride ( 75-C5H5) Ru( PPh3)H (1) together with, as a minor product, the expected monohydride ( Y ~-C ~H ~) R U ( P P ~~) ~H(3) which can be prepared efficiently by treatment of the chloride (2) with NaOMe; reduction of ( q5-C5H5) Ru( Ph2PCH2CH2PPh2)CI ( 4) with LiAlH4 gives only the monohydride ( q5-C5H5)Ru-(Ph2PCH2CH2PPhZ)H (5).

Half-sandwich trihydrido ruthenium complexes

“…Davis et al previously reported that reaction of Cp(Ph 3 P) 2 RuCl with LiAlH 4 in THF affords a 4:1 mixture of Cp(Ph 3 P)RuH 3 and Cp(Ph 3 P) 2 RuH, from which the former complex can be isolated by recrystallization from ether [14]. In our hands, however, difficult-to-separate mixtures of variable ratios of Cp(Ph 3 P)RuH 3 and Cp(Ph 3 P) 2 RuH were produced.…”

“…1. Spectroscopic data for the related compound Cp(Ph 3 P)RuH 3 (1a) have been previously rationalized in terms of a classical C 3v structure, with the bulky phosphine occupying a position trans to the Cp ring and the three hydrides forming an equatorial plane in a pseudo-TBP structure [14]. In fact, the experimental geometry of 1b is similar to that one of the analogous complex Cp * (Ph 3 P)RuH 3 , which can be better described as a fourleg piano-stool [15a].…”

“…This known complex [14] was prepared analogously to CpðPr i 3 PÞRuH 3 , using LiAlH 4 (0.088 g, 2,3 mmol) and [Cp(Ph 3 P)Ru(NCCH 3 ) 2 ]BF 4 (0.550 g, 0.92 mmol). Yield: 0.246 g (62%).…”

“…Previously, only one trihydride complex with unsubstituted Cp ring, Cp(Ph 3 P)RuH 3 (1a), has been reported [14]. By contrast, a family of permethyl substituted complexes Cp * (R 3 P)RuH 3 (Cp * @C 5 Me 5 ) is well described [15], including the X-ray structure of Cp * (Ph 3 P)RuH 3 [16].…”

Fischer–Tropsch, organometallics, and other friends

“…Some examples of the approaches that were used to mimick the direct (stoichiometric) reduction of coordinated CO in a metal complex [9][10][11][12] include (Cp * ) 2 Zr(CO) 2 + 2H 2 /110°C ! (Cp * ) 2 Zr(H)(OMe) [9], followed by hydrolysis to methanol; and [CpFe(CO)-(PMe 3 )Me] + successive (CO; BH 3 ) !…”