The effect of terminal chain modifications on the mesomorphic properties of 4,4'-disubstituted diphenyldiacetylenes |
| |
| Authors: | Mary E. Neubert Michael R. Fisch Sandra S. Keast Julie M. Kim Mark C. Lohman Rachel S. Murray Kyle J. Miller Raj A. Shenoy Michael J. Smith Ryan M. Stayshich Margaret E. Walsh Rolfe G. Petschek George A. Lorenzo Dena C. Burrows Shelly M. Oliver |
| |
| Affiliation: | a Glenn H. Brown Liquid Crystal Intitute, Kent State University, Kent, OH 44242-0001, USAb Physics Department, Case Western Reserve University, Cleveland, OH 44106-7079, USAc Chemistry Department, Wheaton College, Wheaton, IL 60187-5593, USA |
| |
| Abstract: | A variety of terminal chain modifications (Y) were made on the diacetylenes in which X=CnH2n+1, C12H25O and F, and Y=CH2CH(Me)C2H5, COCH3, C≡CC5H11, CnF2n+1CnH2n+1 and CH=CHCO2C3H7. Mesomorphic properties were determined by hot stage polarizing microscopy and DSC. These were compared with those for the dialkyl analogues (X=CmH2m+1, Y=CnH2n+1) and a series of 1- and 2-olefins (Y=CH=CHCnH2n+1 and CH2CH=CHCnH2n+1). The 1-olefin series showed wider range nematics than the dialkyl compounds, whereas the above modifications showed either narrow range nematic phases, no mesophase or higher melting temperatures. New transition temperature and enthalpy data are provided for some of the dialkyl and F-alkyl compounds previously reported, for comparisons. Preliminary birefringence data are also included along with the results of some heat and UV stability studies. |
| |
| Keywords: | |
| 本文献已被 InformaWorld 等数据库收录！ |
|
