Reactions of Ru₃(CO)₁₂ with Diphosphenes — A New Route to 50‐Electron Ru₃P₂nido‐Clusters

Abstract

The reaction of the symmetric diphosphene 2, 4, 6‐(CF3)3‐C6H2‐P=P‐C6H2‐2, 4, 6‐(CF3)3 4 with Ru3(CO)12 led to the 50‐electron Ru3P2 nido‐cluster Ru3(CO)9[μ‐P‐C6H2‐2, 4, 6‐(CF3)3]2 5, which in solution at room temperature displays hindered rotation of the aromatic rings about the C(aryl)—P bonds. The structure of 5 was determined by X‐ray crystal structure analysis; its Ru3P2 centre forms a distorted square pyramid with one ruthenium atom at the apex. One of the two C6H2(CF3)3 groups is also appreciably distorted. Temperature‐dependent 19F NMR studies of the [A3M3X]2 spin system (A = M = CF3, X = 31P) of 5 indicated a rotational barrier ΔG≠ of 82.3 kJ mol‐1 at 141 °C. The same Ru3P2 core was obtained by the reaction of the unsymmetric diphosphene Mes*‐P=P‐Mes 11 with Ru3(CO)12; hindered rotation about the C(aryl)—P bonds was also observed, in this case.

Phosphines and Related Tervalent Phosphorus Systems

“…The reactions of bis(supermesityl)diphosphene and the bis(perfluoroalkylaryl)diphosphene (222) with a ruthenium carbonyl complex have been studied. 667,668 Diphenyldiphosphene, coordinated to a tungsten carbonyl acceptor, has been shown to undergo addition of N,N-dimethylcyanamide to the P¼P bond. 669 Treatment of the diphosphenium salt (223) with lithium diisopropylamide results in a high yield conversion into the diphosphirane (224), alkylation of which gives a diphosphiranium salt.…”