REVERSIBLE AND IRREVERSIBLE COORDINATION OF SMALL MOLECULES TO THE CP(ASTERISK)RU FRAGMENT BY A FACILE CLEAVAGE OF THE RUTHENIUM OXYGEN BOND OF ETA(2) P-BOOLEAN-AND-O-CHELATED (1,3-DIOXAN-2-YLMETHYL)DIPHENYLPHOSPHINE

The complex[Cp*Ru(P similar to O)(P O)][BPh(4)] (1; Cp* = eta(5)-C(5)Me(5); P O = eta(2)(O,P)-chelated (1,3-dioxan-2-ylmethyl)diphenylphosphine sphine; P similar to O = eta(1)(P)-coordinated) is shown to undergo a facile cleavage of its intramolecular ether moiety by reaction with a variety of small molecules. Compound 1 readily takes up ethene whereupon the eta(2)-ethene complex [Cp*RU(P similar to O)(2)(eta(2)-H2C=CH2)][BPh(4)] (2) is generated which is only stable under an atmosphere of C2H4. If 2 is stirred under an atmosphere of argon, it is reversibly converted into the starting compound 1. Hydrogenation of l-hexene to n-hexane with complex I proceeds catalytically. Conversion rates are acceptable at elevated temperatures (> 80 degrees C). The reaction of 1 with sulfur dioxide, carbon disulfide, oxygen, phenylacetylene, and diphenyldiazomethane results in the irreversible coordination of the corresponding molecule to the metal affording the stable complexes [Cp*Ru(P similar to O)(2)(eta(1)-SO2)][BPh(4)] (3), [Cp*Ru(P similar to O)(2)(CS)][BPh(4)] (4), [Cp*Ru(P similar to O)(2)-(eta(2)-CS2)][BPh(4)] (5), [Cp*Ru(P similar to O)(2)(O-2)][BPh(4)] (6), [Cp*Ru(P similar to O)(2)(C=CHPh)][BPh(4)] (7), and [Cp*Ru(P similar to O)(2)(N(2)CPh(2))][BPh(4)] (8), respectively. All compounds are obtained in excellent yields under mild reaction conditions. The structures of 3, 4, and 6 were determined by single-crystal X-ray diffraction. Aside from the coordinated small molecules, the structures are nearly identical and the compounds crystallize in the same monoclinic space group P2(1)/c with Z = 4. The cell dimensions are as follows: for 3, a = 9.526(6) Angstrom, b = 17.195(9) Angstrom, c 38.23(2) Angstrom, beta = 94.73(5)degrees; for 4, a = 9.847(4) Angstrom, b = 17.368(5) Angstrom, c = 38.394(14) Angstrom, beta = 94.57(1)degrees; for 6, a = 19.47(4) Angstrom, b = 13.23(2) beta, c = 22.88(4) Angstrom, beta = 113.36(1)degrees.