DESIGN OF SIDE-CHAIN AND MAIN-CHAIN LIQUID-CRYSTALLINE POLYMERS CONTAINING SUPRAMOLECULAR QUASI-RIGID-RODLIKE MESOGENS OBTAINED FROM COLLAPSED MAIN-CHAIN MACROCYCLICS

The synthesis of the AB(2) mesogenic group xy-1-(4-hydroxyphenyl)-2-(4 -hydroxy-4'-biphenylyl) tridecane (TPT'-OH, 11) and its use in the pre paration of -tetraoxa-25-[(methacryloyloxy)undecanyl]-57-ethyl [12.0.2 .12.0.2]paracyclophane (17), 4,65,76-hexaoxa-25-[(methacryoyloxy)undec anyl]-57, 89-diethyl[12.0.2.12.0.2.12.0.2]paracyclophane (24), and 1,1 2,33,44,65,76,97, 108-octaoxa-25-[(methacryloyloxy)undecanyl]-57,89, 1 21-triethyl[12.0.2.12.0.2.12.0,2.12.0.2] paracyclophane (30) and of th e corresponding polymethacrylates 18, 25, and 31 are described. Monome rs 17, 24, and 30 are the main chain cyclic dimer, trimer, and tetrame r, respectively, of 4-hydroxyphenyl)-2-(4-hydroxy-4'-biphenylyl)butane (TPB', 13) with 11 and 1,10-dibromodecane and, therefore, are attache d to the methacryloyl group through a spacer containing 11 methylenic units. The collapsed conformation of these macrocyclics combined with their degree of oligomerization places these quasi-rigid-rodlike mesog ens side-on in 18, end-on in 25, and in between side-on and end-on in 31. The synthesis of the biselectrophilic macrocyclic main chain dimer s ,28,34-tetraoxa-20,47-bis(bromohexyl)[7.0.2.7.0.2] paracyclophane (4 0) from 4-hydroxyphenyl)-2-(4-hydroxy-4'-biphenylyl)octane (TPO-OH, 36 ) and 1,5-dibromopentane and raoxa-32,70-bis(bromoundecanyl)[12.0.0.2. 12.0.0.2] paracyclophane (46) from 13-hydroxy-1-(4-hydroxyphenyl)-2-(4 -hydroxy-4 ''-terphenylyl)tridecane (TPT-OH, 42) and 1,10-dibromodecan e is also presented. Their phase transfer-catalyzed polyetherification with TPB' produced the main chain polyethers 41 and 47. The mesomorph ic behavior of these first examples of side chain and main chain polym ers containing macrocyclic mesogens is discussed. In spite of the long spacer used in the design of these polymers, they do not crystallize and also do not display smectic phases. 25, 31, and 47 exhibit an enan tiotropic nematic phase, while 18 and 41 are amorphous. The use of the spacer in the construction of both the macrocyclic mesogen and the co rresponding main chain and side chain liquid crystalline polymers prov ides the highest degree of conformational disorder from all known poly mers exhibiting a nematic mesophase.