| Popis: |
Crystal structures of 1-(1-adamantyl)pyrazole, 1a, and 1-(1-adamantyl-3-ol)-4-nitropyrazole, 2a, have been solved by X-ray analysis. The space groups and cell parameters are P21, a, 7.4021(3), b, 10.7529(5),c, 6.9651(2)A, β, 90.206(3)° for 1a with Z = 2 and P2/n, a, 31.1172(14), b, 6.8506(1), c, 12.0313(3)A, β 94.873(3)° for 2a with Z = 8. Refinements were carried out down to R values of 0.043 (Rw, = 0.046) and 0.079 (Rw = 0.061) for the 951 (2σ(I)) and 2461 (3σ(I)) observed reflections respectively. The conformation about the bond between the heterocycle and the carbocycle is discussed on theoretical grounds INDO calculations): the adamantane behaves as a free rotor. The stcricinteractions of the adamantyl residue with the methyl substituents in 2- and 5-position of pyrazole are apparent in the C-13 chemical shifts. |
