Two-dimensional nutation 59Co NMR of solid Co4(CO)12

Autor: Hirokazu Nakayama, Brian T. Heaton, Sadamu Takeda, Nobuo Nakamura, Taro Eguchi, H. Ohki, S. Kernaghan
Rok vydání: 1992
Předmět:
Zdroj: Journal of Organometallic Chemistry. 428:207-212
ISSN: 0022-328X
DOI: 10.1016/0022-328x(92)83230-f
Popis: 59 Co 2D nutation NMR experiments were conducted at 47.485 MHz in order to determine the quadrupole coupling constants ( e 2 Qq/h ) of 59 Co nuclei in solid Co 4 (CO) 12 . The 2D spectrum observed clearly indicates the presence of two inequivalent 59 Co nuclei, Co(apical) and Co(basal). The magnitude of e 2 Qq/h and the asymmetry parameter of the electric field gradient, η, were determined to be 9 ± 2 MHz and 0 for Co(basal), and 15 ± 3 MHz and 0.8 for Co(apical). The large value of η for Co(apical) suggests that the apical Co occupies the site on a pseudo-C 3 axis in the crystalline lattice. These facts are consistent with our previous proposal that a symmetry conserved reorientation of the Co 4 -tetrahedron occurs in the solid state.
Databáze: OpenAIRE