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NMR study of iminophosphine oligomers by 31 P, 15 N and 31 P, 13 C heteronuclear shift correlation
Author(s) -
Gudat D.,
Link M.,
Schröder G.
Publication year - 1995
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.1260330110
Subject(s) - heteronuclear molecule , chemistry , diastereomer , coupling constant , nmr spectra database , carbon 13 nmr , pulse sequence , spectral line , stereochemistry , two dimensional nuclear magnetic resonance spectroscopy , chemical shift , crystallography , heteronuclear single quantum coherence spectroscopy , carbon 13 nmr satellite , nuclear magnetic resonance spectroscopy , nuclear magnetic resonance , computational chemistry , fluorine 19 nmr , physics , particle physics , astronomy
Abstract 2D 31 P, 15 N heteronuclear shift correlation, based on a non‐refocused INEPT pulse sequence with 15 N detection, was applied to a 15 N NMR study of the azadiphosphiridines 1‐5 which are formed by [2 + 1] cycloaddition of iminophosphines, RPNR′. The pulse sequence used allowed consistent assignment of both the 31 P and 15 N NMR spectra in one experiment; by a slight modification, also the signs of numerous 31 P‐ 15 N coupling constants across one or two bonds could be determined. Comparison of the data with those of the azatriphosphetidine 6 (obtained from ID 1 H, 15 N and 31 P, 15 N INEPT spectra) showed the influence of the ring size and conformational effects on the NMR parameters. 31 P, 13 C shift‐correlated 2D spectra were further used to measure (including sign determination) and assign 31 P‐ 13 C coupling constants across one to three bonds in 1‐5. Based on the analysis of the coupling information and the known conformation of 4a, the relative stereochemistry of the diastereomers 4a and b could be derived; further, the comparison of the 31 P‐ 13 C coupling data of 1‐3 with those of the 4a and b allowed the conformations of these derivatives, which were previously unknown, to be determined. The derived information of the constitution and stereochemistry of 1‐5 gives insight into mechanistic details of the iminophosphine [2 + 1] cycloaddition.