Journal of the American Chemical Society p. 6937 - 6943 (1987)
Update date:2022-08-12
Topics:
Ingold, K. U.
Walton, J. C.
Cycloalkylmethyl radicals having 7- to 15-membered rings (excluding cyclotetradecylmethyl) have been generated and examined by EPR spectroscopy.All the cycloalkylmethyl radicals from the 9-membered ring upward show two distinguishable conformers, though there may be additional conformers present with cyclodecylmethyl and cyclopentadecylmethyl radicals.All the cycloalkylmethyl radicals from the 10-membered ring upward have one conformer, the quasi-equatorial, QE, with an Hβ hfs in the range 27.7-32.0 G at 140 K and one conformer, the quasi-axial, QA, with an Hβ hfs in the range 38.3-40.4 G at 140 K.The QE and QA conformers have been assigned to species in which the CH2. group occupies "outer-edge" and "corner" sites, respectively, in the preferred conformations of the cycloalkanes.The EPR results indicated that the preferred conformations of the C9, C10, C11, C12, C13, and C15 rings were <333>, <2323>, <335>, <3333>, <346>, and <33333>, respectively.Arrhenius parameters for ring-atom site exchange in the cycloalkylmethyl radicals have been determined from the exchange broadening in the EPR spectra.These EPR barriers are compared with literature data on cycloalkane free energy barriers measured by NMR and enthalpic barriers estimated by force field and related methods.
View MoreContact:+86-574- 87178138; 87297407
Address:No. 809, Liudingxingzuo, cangsong road, Ningbo, China
Suzhou HeChuang Chemical Co.,Ltd.
Contact:+86-512-88800520
Address:No.9 Guanchao Rd,Changshu Advanced Materials Industy Park
Chongqing Yawei Fine Chemical Co.,Ltd
Contact:0086-23-62849407
Address:Ziyou village, Nanquan town, Banan district, Chongqing China
Shanghai Bosman Industrial Co., Ltd
Contact:86-21-63065878-8006
Address:Rm907, No.1611, North Sichuan Road, Hongkou District, Shanghai, 200080 China
Zhejiang Kangfeng Chemical Co.,LTD.
Contact:+86-579-86709687
Address:Xueshizhai Industrial Zone, Weishan Town,Dongyang City, Zhejiang Province ,China
Doi:10.1007/BF02494398
(1999)Doi:10.1016/S0040-4039(03)01203-6
(2003)Doi:10.1002/anie.201709368
(2017)Doi:10.1016/j.cattod.2011.10.004
(2012)Doi:10.1039/c3cc48065h
(2014)Doi:10.1002/cssc.201601322
(2017)