23459-12-3Relevant academic research and scientific papers
Barriers to Internal Rotation in 1,3,5-Trineopentylbenzenes.10. 13C and 19F NMR Band Shape Studies and Force Field Calculations.
Andersson, Sven,Drakenberg, Torbjoern
, p. 602 - 615 (2007/10/02)
1,3,5-Trineopentylbenzenes (TNB) with one or two benzylic substituents in each neopentyl group were synthesized.The substituents were F, Cl, Br, I, OCH3, OCOCH3, OSi(CH3)3 and CH3 and, in cases of disubstitution, F, Cl, Br, CH3 and Cl, CH3 and Br and -SCH2CH2S-.Barriers to internal Csp3-Csp2 (aryl) and Csp3-Csp3 rotation were estimated by 13C and 19F NMR band shape methods.Estimated barriers in the TNB series were found to be very close to those found for the corresponding mononeopentylbenzenes.For some of the compounds studied, molecular mechanics (MM) calculations were performed with the Allinger MMP1 program.Differ ences between calculated and experimental estimated barriers were found, and possible sources of these discrepancies in terms of parameters used in the MMP1 program are discussed.
