Reactions of CO₂ and CS₂ with [RuH(η²-CH₂PMe₂)(PMe₃)₃]

Abstract

Carbon disulfide reacted with the cyclometalated ruthenium complex [RuH(η 2 -CH 2 PMe 2 )(PMe 3 ) 3 ] (1) at low temperature to yield the dithioformate complex [Ru(η 1 -SC(S)H)(η 2 -CH 2 PMe 2 )(PMe 3 ) 3 ] (4), where the CS 2 inserts into the metal hydride bond. On warming, complex 4 rearranges to give the known complex [Ru(S 2 CHPMe 2 CH 2 -κ 3 S,S,C)(PMe 3 ) 3 ] (3), where the CS 2 is inserted in a metal phosphorus bond. Further reaction of this complex with excess CS 2 over a period of days resulted in insertion of a second CS 2 unit into one Ru−S bond to yield [Ru(SC(S)SCH(-S)PMe 2 CH 2 -κ 3 S,S,C)(PMe 3 ) 3 ] (5). Complex 5 was characterized crystallographically and by multinuclear NMR spectroscopy. In contrast, reaction of [RuH(η 2 -CH 2 PMe 2 )(PMe 3 ) 3 ] (1) with CO 2 resulted in insertion of CO 2 into the Ru−C bond to give [RuH(OC(O)CH 2 PMe 2κ 2 O,P)(PMe 3 ) 3 ] (2). Low-temperature NMR spectroscopic studies did not show any evidence for prior formation of a formate complex.

Metal- and Ligand-Assisted CO2 Insertion into Ru–C, Ru–N, and Ru–O Bonds of Ruthenium(II) Phosphine Complexes: A Density Functional Theory Study

“…Although the insertion reaction was more facile for the Ru–H bond than Ru–C, a thermodynamically stable Ru–C-inserted product trans -[Ru(DMPE) 2 ­(O 2 ­CMe)(H)] was observed, suggesting a rapid deinsertion of CO 2 from trans -[Ru(DMPE) 2 (Me)(O 2 CH)], the Ru–H-inserted product. In a similar study using a cyclometalated [RuH(η 2 -CH 2 PMe 2 )(PMe 3 ) 3 ] complex, Field et al reported the relative reactivity of the Ru–H and Ru–C bonds with respect to CO 2 insertion . They found that CO 2 inserts into the Ru–C bond with the apparent absence of any observable CO 2 insertion into the Ru–H bond.…”

“…They found that CO 2 inserts into the Ru–C bond with the apparent absence of any observable CO 2 insertion into the Ru–H bond. It again suggests that metal hydride insertions and subsequent decarboxylation are too fast to observe on the NMR time scale …”

Recent Advances in the Chemistry of Metal Carbamates

“…The "weak point" in the apparently unscratchable robustness of carbon dioxide is the susceptibility to nucleophilic attacks at the carbon atom [22][23][24]. Thus, a range of nucleophilic reagents, including neutral N-heterocyclic carbenes [25,26], are known to react with CO 2 even under mild conditions, and some chemistry at transition metal centers is provided by the possibility of CO 2 insertion into the bond between a metal atom and a suitable anionic ligand, e.g., alkyl, allyl, alkoxide and hydride [27][28][29][30][31][32]. In this context, amines are key reactants towards carbon dioxide, and indeed carbon dioxide/amine systems have been intensively investigated in the field of capture/storage [33][34][35] and exploited for the incorporation of the CO 2 moiety within organic structures [36][37][38][39].…”

Bimetallic Perthiocarbonate Complexes of Cobalt: Synthesis, Structure and Bonding

“…In this context, Jagirdar’s group demonstrated the insertion of CS 2 into one of the Ir-H bonds in [Ir(H) 5 (PCy 3 ) 2 ] to afford the dihydrido dithioformate complex cis -[Ir(H) 2 ( ƞ 2 -S 2 CH)(PCy 3 ) 2 ] ( A ), accompanied by the elimination of H 2 [ 7 ]. Similarly, the cyclometalated ruthenium complex [Ru(S 2 C(H)PMe 2 CH 2 - κ 3 S,S,C)(PMe 3 ) 3 ] was shown to react with an excess of CS 2 , which undergoes a second insertion into a Ru–S bond to yield [Ru(SC(=S)SCH(–S)PMe 2 CH 2 - κ 3 S,S,C)(PMe 3 ) 3 ] ( B ) [ 8 ]. Wang and coworkers reported the disproportionation of CS 2 when reacted with the Me 2 C and Me 2 Si doubly bridged bis(cyclopentadienyl) dinuclear molybdenum carbonyl complex (Me 2 C)(Me 2 Si)[( ƞ 5 -C 5 H 3 )Mo(CO) 3 ] 2 , which led to the formation of complex C [ 9 ].…”