| Abstract
| - The unprecedented ruthenium carbene complexes [Ru(η6-p-cymene)(κ2(C,N)-C[P{NP(O)(OR)2}Ph2]2)] (R = Ph, Et) and [Ru(η6-p-cymene)(κ2(C,N)-C[P{NP(O)(OPh)2}Ph2][P{NP(O)(OEt)2}Ph2])] have been obtained from the bis(iminophosphorano)methane ligands CH2[P{NP(O)(OR)2}Ph2]2 (R = Ph, Et) and CH2[P{NP(O)(OPh)2}Ph2][P{NP(O)(OEt)2}Ph2], respectively, via deprotonation of the methylenic PCH2P unit.
- The symmetric bis(iminophosphorano)methanes CH2[P{NP(O)(OR)2}Ph2]2 (R = Ph (2a),Et (2b)) have been obtained by treatment of bis(diphenylphosphino)methane with a 2-foldexcess of phosphorylated azides (RO)2P(O)N3. The asymmetric ligand CH2[P{NP(O)(OPh)2}Ph2][P{NP(O)(OEt)2}Ph2] (2c) has been prepared by oxidation of Ph2PCH2P{NP(O)(OEt)2}Ph2 (1b) with (PhO)2P(O)N3. Compounds 2a−c can be deprotonated withsodium hydride, affording the corresponding methanide anions NaCH[P{NP(O)(OR)2}Ph2]2 (R = Ph (3a), Et (3b)) and NaCH[P{NP(O)(OPh)2}Ph2][P{NP(O)(OEt)2}Ph2] (3c).Treatment of [{Ru(η6-p-cymene)(μ-Cl)Cl}2] with 3a−c results in the formation of the neutralcomplexes [RuCl(η6-p-cymene)(κ2(C,N)-CH[P{NP(O)(OR)2}Ph2]2)] (R = Ph (4a), Et (4b))and [RuCl(η6-p-cymene)(κ2(C,N)-CH[P{NP(O)(OPh)2}Ph2][P{NP(O)(OEt)2}Ph2])] (4c),via selective κ2(C,N) coordination of the bis(iminophosphorano)methanide anions to ruthenium. The cationic species [Ru(η6-p-cymene)(κ3(C,N,O)-CH[P{NP(O)(OR)2}Ph2]2)][SbF6](R = Ph (5a), Et (5b)) and [Ru(η6-p-cymene)(κ3(C,N,O)-CH[P{NP(O)(OPh)2}Ph2][P{NP(O)(OEt)2}Ph2])][SbF6] (5c/5c‘) have been also prepared by reaction of 4a−c with AgSbF6.Deprotonation of complexes 4a−c or 5a−c‘ with NaH generates the unprecedentedruthenium carbenes [Ru(η6-p-cymene)(κ2(C,N)-C[P{NP(O)(OR)2}Ph2]2)] (R = Ph (6a), Et(6b)) and [Ru(η6-p-cymene)(κ2(C,N)-C[P{NP(O)(OPh)2}Ph2][P{NP(O)(OEt)2}Ph2])] (6c).The structures of compounds 2a, 5a, and 6a have been confirmed by X-ray crystallography.DFT calculations on a model for complexes 6a−c, [Ru(η6-C6H6)(κ2(C,N)-C[P{NP(O)(OMe)2}Me2]2)], suggest a nucleophilic character for the carbon atom in RuC. In agreementwith this theoretical prediction, protonation of complexes 6a−c with HCl or HBF4 takesplace selectively on the carbenic carbon, regenerating 4a−c or 5a−c‘, respectively.
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