Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases p. 359 - 382 (1984)
Update date:2022-08-02
Topics:
Gebregiorgis, Taddesse
Gordon, Manfred
Old and recent data on equilibria and kinetics of methylolation of urea and melamine are analysed.The theoretical framework affords a sequence, claimed to be canonical of successive phenomenological approximations.The theory, expounded earlier, begin with two successive schemes whose essentials go back to early work by Pauling and by Flory.The two stages here suffice to show that all the data from eight laboratories, covering the six-membered family of methylol ureas and rhe ten-membered family of methylol melamines, are in quantitative agreement, a circumstance unsespected by other workers in the field.The statisticalthermodynamic and kinetic principles involved are therefore expounded in more detail than before.Using them, very small substituent effects (e.g O.35 kJ kol-1 are deduced with high significance and accuracy.Owing largly to the recent measurement by Tomita, the methylol melamines are claimed currently to be the thermdinamically best characterised family in the chemical literature.A challenge arises for theoretical chemists to test quantum-theoreticaltechniques against the measured energetics of substituent effects in this family, and to exploit for other families the graph-theoretical analysis of molecular additivity which underlies the approximation schemes, which already well tested.
View MoreTIANJIN GST CHEMICAL TECHNOLOGY CO., LTD
Contact:+86-22-25210964
Address:Room. 208, No. -12-C, No. 13, Xinbei Road, Tanggu District, New Haixin Area, Tianjin City, China
Zhejiang Sucon Silicone Co.,Ltd
Contact:+86-575-88046692
Address:Qisheng Rd., Paojiang Industrial Zone, Shaoxing, Zhejiang, China.
Xi'an North Information Industry Co., Ltd. Weilv Chemical Department
Contact:+86-29-88156413
Address:Jixiang Road 99 Xi'an Shaanxi Province
Contact:+86-512-69561895
Address:No.111, Building A4, 218 Xinghu Street, Suzhou Industrial Park, P. R. China
Contact:86 311 85902108 / 85902109
Address:room 1001-1005 ,huanghe Road ,shijiazhuang ,China
Doi:10.1039/b206102c
(2002)Doi:10.1002/1521-3749(200209)628:9/10<2104::AID-ZAAC2104>3.0.CO;2-A
(2002)Doi:10.1021/ja00990a049
(1967)Doi:10.1016/S0223-5234(02)01376-4
(2002)Doi:10.1016/S0040-4020(01)96974-1
(1965)Doi:10.1002/1521-3773(20021018)41:20<3870::AID-ANIE3870>3.0.CO;2-Q
(2002)