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Dynamic 1 H NMR study around the carbon–carbon single bond and partial carbon–carbon double bond in the two particular phosphorus ylides and in an enaminoester
Author(s) -
HabibiKhorassani Sayyed Mostafa,
Ebrahimi Ali,
Maghsoodlou Malek Taher,
SameSalari Sara,
Nasiri Shahin,
Ghasempour Hojjat
Publication year - 2011
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.2735
Subject(s) - chemistry , single bond , carbon fibers , double bond , ylide , carbon 13 nmr , carbon–carbon bond , nuclear magnetic resonance spectroscopy , crystallography , stereochemistry , organic chemistry , catalysis , alkyl , composite number , composite material , materials science
Herein, a series of separate dynamic 1 H NMR effects are reported at different temperatures within a particular enaminoester involving a phenanthridine. These effects are attributed to restricted rotation around the two single bonds such as carbon–carbon (H a CCH b ) and nitrogen–carbon (NCCOOCH 3 ). Activation energies ( E a ) for these interconversion processes in their rotational isomers are equal to 20 and 20 ± 1 kJ mol −1 , respectively. In addition, three dynamic 1 H NMR effects are investigated at different temperatures for a particular phosphorus ylide involving a 2‐indolinone around the carbon–carbon single bond (HCCPPh 3 ) within the two Z ‐ and E ‐rotational isomers and partial carbon–carbon double bond (OCH 3 ‐CC‐PPh 3 ). Activation energies ( E a ) for these interconversion processes in rotational isomers are equal to 53, 63 and 73 ± 1 kJ mol −1 , respectively. This behavior was also observed for other phosphorus ylide containing 2‐mercaptobenzoxazole around the carbon–carbon single bond and partial carbon–carbon double bond with their relevant activation energies containing 13, 10 and 75 ± 1 kJ mol −1 , respectively. Copyright © 2011 John Wiley & Sons, Ltd.