SYNTHESES, PROPERTIES, AND X-RAY CRYSTAL-STRUCTURES OF STABLE METHYLIDENE COMPLEXES OF THE FORMULA [(ETA-C5ME5)RE(NO)(L)(=CH2)]+PF6- Academic Article uri icon

abstract

  • Reaction of Re2(CO)10 with pentamethylcyclopentadiene at 150-210 C yields (-C5Me5)Re(CO)3 (6). Treatment of 6 with [formula-ommited] gives [formula-ommited] (7). Reaction of 7 with C6H5I+-O-/CH3CN yields [formula-ommited] (8), which is subsequently treated with L (a, L = PPH3; b, L = P(OPh)3) to give [formula-ommited] (9a, 9b). Reduction of 9a and 9b with Li(C2H5)3BH/BH3 and NaBH4, respectively, yields (p-C5Me5)Re(NO)(L)(CH3) (10a, 10b). When 10a and 10b are treated with [formula-ommited], the stable (>100 C as solids) methylidene complexes [formula-ommited] (4) and [formula-ommited] (5) form. Properties of the =CH2 ligands in 4 and 5 are studied in detail: G*rot, (~114 C) 19 kcal/mol; IR v=CH2: 4, 2987/2972 and 2922 cm-1; 5, 2987/2976 and 2920 cm-1; v=CD2: 4-d2, 2246/2239 and 2181 cm-1; 5-d2, 2245/2238 and 2187 cm-1; NMR 1J13C-1H(5) = 154 and 143 Hz. The -160 C X-ray crystal structure of 4 shows =CH2/NO disorder. The room-temperature X-ray crystal structure of 5 indicates space group P21/c, a = 8.666 (3) A,b= 12.387 (5) , c = 34.90 (1) , = 102.34 (3), V = 3360 (2) 3, Z = 4, calcd = 1.82 g cm-3. For 3038 reflections (I0 3.0[formula-ommited], R = 0.057 and Rw = 0.064. The Re=CH2 bond length is 1.898 (18) A, and the =CH2 plane is essentially parallel to the Re-NO bond. This provides optimal overlap with the d orbital HOMO on rhenium. 1983, American Chemical Society. All rights reserved.

published proceedings

  • JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

author list (cited authors)

  • PATTON, A. T., STROUSE, C. E., KNOBLER, C. B., & GLADYSZ, J. A.

citation count

  • 115

complete list of authors

  • PATTON, AT||STROUSE, CE||KNOBLER, CB||GLADYSZ, JA

publication date

  • September 1983