340127-71-1Relevant academic research and scientific papers
A study of C-F···M+ interaction: Alkali metal complexes of the fluorine-containing cage compound
Takemura,Kon,Kotoku,Nakashima,Otsuka,Yasutake,Shinmyozu,Inazu
, p. 2778 - 2783 (2001)
The C-F···M+ interaction was investigated by employing a cage compound 1 that has four fluorobenzene units. The NMR (1H, 13C, and 19F) spectra and X-ray crystallographic analyses of 1 and its metal complexes showed clear evidence of the interaction. Short C-F···M+ distances (CF···K+, 2.755 and 2.727 A; C-F···Cs+ 2.944 and 2.954 A) were observed in the crystalline state of K+ ? 1 and Cs+ ? 1. Furthermore, the C-F bond lengths were elongated by the interaction with the metal cations. By calculating Brown's bond valence, it is shown that the contribution of the C-F unit to cation binding is comparable or greater than the ether oxygen in the crystalline state. Representative spectroscopic changes implying the C-F···M+ interaction were observed in the NMR (1H, 13C, and 19F) spectra. In particular, 133Cs-19F spin coupling (J = 54.9 Hz) was observed in the Cs+ complex.
