Journal of Physical Chemistry p. 1768 - 1774 (1990)
Update date:2022-08-16
Topics:
Chevalier, Yves
Perchec, Pierre Le
The conformation of flexible zwitterionic molecules in solutions of polar solvents is studied by means of a NMR chemical shift method.This method makes use of chemical shift changes of NMR lines, induced by the electrostatic field caused by the electrical charges of the zwitterion.The electrostatic field at the observed nucleus is calculated, taking distances of zwitterionic (trimethylammonio)alkanoates in aqueous and methanolic solutions are then deduced from the 13C NMR chemical shift data as a function of the number of methylenes linking the cationic and anionic groups of the zwitterion.The comparison of experimental data with the end to end distances predicted by the rotational isomerism state theory shows that the polymethylene chain has a more folded conformation than the free chain.Electrostatic attraction between the two zwitterionic charges is thus important, although it could be expected that it could be offset by steric hindrance, i.e., by the bulkiness of terminal charged groups.
View MoreShanghai Haoyuan Chemexpress Co., Ltd.
Contact:86-21-51870955;58998985;58999585
Address:Room 601, No. 2 BLD, NO. 720, Cailun Road, Zhangjiang, Shanghai, China
Shenyang NovPharm Technology Co., Ltd.
Contact:.+86-24-24165786
Address:Room 306, Hongjin Mansion, No. 36-1, Wanliutang Rd., Shenhe District, Shenyang, Liaoning, P.R.C.
Suzhou HeChuang Chemical Co.,Ltd.
Contact:+86-512-88800520
Address:No.9 Guanchao Rd,Changshu Advanced Materials Industy Park
Suzhou BEC Fine Chemicals Co., Ltd.
website:http://www.bek.com.cn
Contact:0512-68095917 18913193865
Address:6, Jin Shan Road, Suzhou New District, 215011 China Suzhou Nations Pharmaceutical Innovation Center Inside
Luzhou North Chemical Co., Ltd.
Contact:+86-830-2796784;+86-830-2796776
Address:Gaoba, Longmatan District, Luzhou, Sichuan Province
Doi:10.1016/S0022-328X(00)88720-3
(1975)Doi:10.1016/j.jphotochem.2020.112738
(2020)Doi:10.1016/S0040-4020(01)86730-2
(1988)Doi:10.1021/ja00469a035
(1978)Doi:10.1002/ejic.201000979
(2011)Doi:10.1021/acs.joc.5b02873
(2016)