13960-80-0Relevant articles and documents
Nonadditivity of secondary deuterium isotope effects on basicity of trimethylamine
Perrin, Charles L.,Dong, Yanmei
, p. 11143 - 11148 (2008)
Secondary deuterium isotope effects (IEs) on basicities of isotopologues of trimethylamine have been accurately measured by an NMR titration method applicable to a mixture. Deuteration definitely increases the basicity, by ～0.021 in the ΔpK per D. The IE is attributed to the lowering of the CH stretching frequency and zero-point energy by delocalization of the nitrogen lone pair into the C-H antibonding orbital. Because this depends on the dihedral angle between the lone pair and the C-H, a further consequence is a preference for conformations with H antiperiplanar to the lone pair and D gauche. This leads to a predicted nonadditivity of IEs, which is confirmed experimentally. It is found that the decrease in basicity, per deuterium, increases with the number of deuteriums. The nonadditivity of IEs is a violation of the widely assumed Rule of the Geometric Mean.
Novel Raman-tagged sphingomyelin that closely mimics original raft-forming behavior
Cui, Jin,Matsuoka, Shigeru,Kinoshita, Masanao,Matsumori, Nobuaki,Sato, Fuminori,Murata, Michio,Ando, Jun,Yamakoshi, Hiroyuki,Dodo, Kosuke,Sodeoka, Mikiko
supporting information, p. 2989 - 2994 (2015/08/03)
Abstract Three Raman probes of sphingomyelin (SM) were synthesized and evaluated for their applicability to imaging experiments. One probe containing a hydroxymethyl-1,3-butadiyne moiety in the polar head group showed strong scattering. The solid-state 2H NMR spectra of this probe in oriented bilayer membrane revealed excellent compatibility with natural SM in phase behavior since the probe undergoes phase separation to form raft-like liquid ordered (Lo) domains in the raft-mimicking mixed bilayers.
