115227-29-7Relevant academic research and scientific papers
Carbon suboxide as a C1 reagent. Sequential cleavage of CO from C3O2 at a metal center to give WCl2(CO)(PMePh2)2{C,C′:η 2-C(O)CPMePh2} and WCl2(CO)(PMePh2)2(≡CPMePh2)
List, Adam K.,Hillhouse, Gregory L.,Rheingold, Arnold L.
, p. 2010 - 2016 (2008/10/08)
Carbon suboxide (O=C=C=C=O) reacts with toluene solutions of WCl2(PMePh2)4 (1) in a 1:1 stoichiometry to afford WCl2(CO)(PMePh2)2{C,C′:η 2-C(O)CPMePh2} (2) in high yield. The reaction is formally analogous to the reported reactions of 1 with other heterocumulenes (O=C=O, RN=C=O, and RN= C=NR) except that in the cases of these latter three reagents, tungsten oxo or imido complexes are formed whereas in the case of C3O2, a C-C rather than a C-O or C-N bond is cleaved; the probable resulting ketenylidene intermediate is apparently trapped by PMePh2 to give the novel (diphenylmethyl-phosphoranylidene)ketene derivative. 2 crystallizes in the monoclinic space group P21/n with Z = 4, a = 11.400 (4) A?, b = 16.029 (4) A?, c = 21.569 (9) A?, and β = 97.13 (3)°. The least-squares refinement converged to R(F) = 0.041 and Rw(F) = 0.052 for the 4333 unique data with F > 3σ(F). At 35°C in CHCl3 solution, 2 undergoes an irreversible loss of CO to give the unusual tungsten phosphinocarbyne complex WCl2-(CO)(PMePh2)2(≡CPMePh2) (3). Carbon suboxide thus serves as a carbon atom synthon by sequential loss of two molecules of carbon monoxide. Treatment of toluene solutions of 1 with (triphenylphosphoranylidene)ketene, O=C=CPPh3, affords a triphenylphosphine analogue of 3, WCl2(CO)-(PMePh2)2(≡CPPh3) (4), in excellent yield. 4 crystallizes in the monoclinic space group P21/c with Z = 4, a = 11.283 (2) A?, b = 14.932 (3) A?, c = 24.947 (6) A?, and β = 100.55 (2)°. The least-squares refinement converged to R(F) = 0.041 and Rw(F) = 0.043 for the 5205 unique data with Fo > 3σ(Fo). The phosphinocarbyne ligand of 4 is bound to W in a nearly linear fashion, with W-C(2)-P(3) = 171.2 (5)°, and the W-C(2) bond distance of 1.823 (7) A? is typical of W-C triple-bond distances found in other structures.
