Exceptionally large13C-13C coupling constants of compounds containing a CF3 group

Autor:	Willy Gombler
Rok vydání:	1990
Předmět:	Coupling constant chemistry.chemical_classification Ketone Stereochemistry chemistry.chemical_element General Chemistry Nuclear magnetic resonance spectroscopy Fluorine-19 NMR Electronegativity Crystallography chemistry Group (periodic table) General Materials Science Inductive effect Carbon
Zdroj:	Magnetic Resonance in Chemistry. 28:553-556
ISSN:	1097-458X 0749-1581
DOI:	10.1002/mrc.1260280615
Popis:	Coupling constants, 1J(13C,13C), of compounds containing a CF3 group are reported. The values for the coupling of the CF3 carbon with the neighbouring carbon are exceptionally large. In a series of compounds in which the CF3 group is bonded to an sp3, sp2 or sp carbon the 1J(C,C) values show a good linear correlation with the product of the s characters of the two orbitals forming the CC bond. Furthermore, compounds containing a CCl3 group have been measured. A correlation of the 1J(CC) values with the sum of the group electronegativities in compounds of the CX3-CY3 type is found. The results for compounds containing highly electronegative substituents suggest a contribution to the CC coupling from a relatively large variation of the valence-shell s-orbital density at the carbon nucleus, Sc2(0). Additional 13C and 19F NMR data of the compounds are presented.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::d23f2d58d8145d35f887ac9e1faf71a2 https://doi.org/10.1002/mrc.1260280615 Zobrazit plný text záznamu Plný text