Organic Magnetic Resonance p. 78 - 82 (1981)
Update date:2022-08-29
Topics:
Brzezinski, Bogumil
Szafran, Miroslaw
Chemical shifts of H-bonded protons in tetrabutylammonium hydrogen maleate and 14-substituted picolinic acid N-oxides have been measured in a number of dry solvents, of different activity, in order to distinguish between symmetrical single minimum and asymmetrical hydrogen bonds.In tetrabutylammonium hydrogen maleate the resonance was observed at 20.70 ppm and its was independent of the nature of the solvent used.The chemical shift value of picolinic acid N-oxide varies with the solvent.These observations suggest that the hydrogen bond is symmetrical in tetrabutylammonium hydrogen maleate but that it is asymmetrical in picolinic acid N-oxide.The chemical shifts of substituted picolinic acid N-oxides were correlated with ?p, ?m and ΔpKa.The substituent and solvent effects are compared and the position of the intramolecular H-bonded protons in picolinic acid N-oxides are estimated and discussed.
View MoreHunan Dinuo Pharmaceutical Co.,Ltd.
Contact:86-731-88280100*8561
Address:Bio-pharmaceutical industrial park, Liuyang, Hunan, China
Chengdu ZY Biochemical Technology Co., LTD
Contact:0086-28-88680086
Address:170 Qingpu Road, Shouan Town, Pujiang County
GuangZhe ANFA chemical co.,Ltd
Contact:86-579-87262335
Address:Guangzhe industrial area ,shaowu city ,Fujiang
NINGXIA DARONG CHEMICALS & METALLURGY CO.,LTD.
Contact:86-952-2179751
Address:Darong Road, Dawukou, Shizuishan, Ningxia 753001, China
JIAXING SUNS INTERNATIONAL TRADE CO LTD
Contact:18367306858
Address:No.123,Huixin Avenue,Huimin Dist
Doi:10.1039/a700045f
(1997)Doi:10.1246/cl.1994.2135
(1994)Doi:10.1039/CT8936300821
(1893)Doi:10.1016/j.mcat.2020.111106
(2020)Doi:10.1080/15533174.2011.591875
(2011)Doi:10.1016/j.chemphys.2009.09.009
(2009)