Reactivity of Terminal, Electrophilic Phosphinidene Complexes of Molybdenum and Tungsten. Nucleophilic Addition at Phosphorus and P-P Bond Forming Reactions with Phosphines and Diphosphines
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- 作者：Brian T. Sterenberg ; Ozan Sanli Senturk ; Konstantin A. Udachin ; Arthur J. Carty
- 刊名：Organometallics
- 出版年：2007
- 出版时间：February 12, 2007
- 年：2007
- 卷：26
- 期：4
- 页码：925 - 937
- 全文大小：265K
- 年卷期：v.26,no.4(February 12, 2007)
- ISSN：1520-6041
文摘
Reaction of the terminal electrophilic phosphinidene complexes [Cp*M(CO)3{PN(i-Pr)2}][AlCl4] (3,M = Mo; 4, M = W) with PEt3 results in replacement of a metal carbonyl by the phosphine. The reactionsoccur via initial nucleophilic attack by the phosphine at the phosphinidene phosphorus, followed bycarbonyl loss and migration of the phosphine to the metal. Reactions of 3 and 4 with bis(dimethylphosphino)methane (dmpm) lead to [Cp*M(CO)2{P(N(i-Pr)2)P(Me2)CH2P(Me2)-
2P1,P4}][AlCl4](9, M = Mo; 10, M = W), in which one end of the diphosphine coordinates to phosphorus and the otherend coordinates to the metal. The reactions proceed by initial nucleophilic attack by one end of thediphosphine at phosphorus, followed by carbonyl loss and coordination of the other end of the ligand tothe metal. Compound 3 (M = Mo) reacts with bis(dimethylphosphino)ethane (dmpe) to give the analogousproduct [Cp*Mo(CO)2{P(N(i-Pr)2)P(Me2)CH2CH2P(Me2)-2P1,P5}][AlCl4] (12), in which the two endsof the dmpe ligand coordinate to phosphorus and molybdenum, respectively. Reaction of compound 4(M = W) with dmpe leads to two products, [Cp*W(CO)2{P(N(i-Pr)2)P(Me2)CH2CH2P(Me2)-2P1,P5}][AlCl4] (13) and [{Cp*W(CO)2(PN(i-Pr)2)}2(
-dmpe)][AlCl4]2 (14). Compound 13 is analogous to 12.In compound 14, the two ends of the diphosphine ligand displace carbonyl ligands from two moleculesof 4, resulting in a novel bis-phosphinidene structure in which the diphosphine ligand bridges two metalcenters, each of which retains a terminal phosphinidene ligand. Loss of an additional carbonyl ligandfrom 12, followed by migration of one end of the phosphine from phosphorus to the metal, results inre-formation of a terminal phosphinidene ligand, leading to [Cp*Mo(CO)(PN(i-Pr)2)(dmpe-2P)][AlCl4](17). The structural characterization of the phosphine adducts and carbonyl substitution products of theterminal phosphinidene complexes 3 and 4 has provided valuable insights into metal-phosphinidenebonding in these compounds.
2P1,P4}][AlCl4](9, M = Mo; 10, M = W), in which one end of the diphosphine coordinates to phosphorus and the otherend coordinates to the metal. The reactions proceed by initial nucleophilic attack by one end of thediphosphine at phosphorus, followed by carbonyl loss and coordination of the other end of the ligand tothe metal. Compound 3 (M = Mo) reacts with bis(dimethylphosphino)ethane (dmpe) to give the analogousproduct [Cp*Mo(CO)2{P(N(i-Pr)2)P(Me2)CH2CH2P(Me2)-2P1,P5}][AlCl4] (12), in which the two endsof the dmpe ligand coordinate to phosphorus and molybdenum, respectively. Reaction of compound 4(M = W) with dmpe leads to two products, [Cp*W(CO)2{P(N(i-Pr)2)P(Me2)CH2CH2P(Me2)-2P1,P5}][AlCl4] (13) and [{Cp*W(CO)2(PN(i-Pr)2)}2(-dmpe)][AlCl4]2 (14). Compound 13 is analogous to 12.In compound 14, the two ends of the diphosphine ligand displace carbonyl ligands from two moleculesof 4, resulting in a novel bis-phosphinidene structure in which the diphosphine ligand bridges two metalcenters, each of which retains a terminal phosphinidene ligand. Loss of an additional carbonyl ligandfrom 12, followed by migration of one end of the phosphine from phosphorus to the metal, results inre-formation of a terminal phosphinidene ligand, leading to [Cp*Mo(CO)(PN(i-Pr)2)(dmpe-2P)][AlCl4](17). The structural characterization of the phosphine adducts and carbonyl substitution products of theterminal phosphinidene complexes 3 and 4 has provided valuable insights into metal-phosphinidenebonding in these compounds.