Journal of the Chemical Society. Perkin transactions II p. 1117 - 1120 (1986)
Update date:2022-08-03
Topics:
Pruszynski, Przemyslaw
Jarczewski, Arnold
Kinetic studies have been carried out on the proton-transfer reactions of (i) 4-nitrobenzyl cyanide (4-NBC) with tetramethylguanidine (TMG) and (ii) 4-nitrophenylphenylcyanomethane (4-NPPCM) with 1,8-bis(dimethylamino)naphthalene (DMAN) in acetonitrile.The reaction (i) has a moderate enthalpy of activation (ΔH++ = 25 kJmol-1) and a negative entropy of activation (ΔS++ = -98 Jmol-1K-1).The deuterium kinetic isotope effect is large.The reaction (ii) of the more hindered molecule 4-NPPCM and DMAN has similar activation parameters (ΔH++ = 26 kJmol-1, ΔS++ = -140 Jmol-1K-1), but the kinetic isotope effect is considerably larger; also ΔHD++ - ΔHH++ is larger (13 kJmol-1) and AH/AD is small, indicating a considerable tunnelling effect.Evidence that the larger isotope effect are not artefacts of hydrogen exchange is presented.The tunnelling factor is estimated.
View MoreContact:+86-511-88790000
Address:338 North Yushan Rd, Zhenjiang, Jiangsu 212016
Suzhou Chiral Pharmaceuticals Co., Ltd.
Contact:86-0512-63197058
Address:Building A, No. 2358, Chang'an Road, Wujiang Science Park
website:http://www.amadischem.com
Contact:86-571-89925085
Address:Watts Cosine.No.166.Xiangmao Road.
Shifang Taifeng New Flame Retardant Co., Ltd
Contact:02884721008
Address:tingjiang industrial park, hefeng town
Zouping Fuhai Technology Development Co., Ltd.
Contact:+0532-86934525 18660293207
Address:jiuhu town industrial park Zouping County,bingzhou Provincejiuhu town industrial park
Doi:10.1002/cplu.201402072
(2014)Doi:10.1016/j.ejmech.2009.06.029
(2009)Doi:10.1021/jo060334s
(2006)Doi:10.1039/b605278a
(2006)Doi:10.1016/j.tetlet.2006.04.132
(2006)Doi:10.1016/j.bmcl.2007.10.055
(2007)
