Dimethyl 4,4 -biphenyldicarboxylate

Photophysical Processes in Dimethyl 4,4 -Biphenyldicarboxy-late (4,4I-BPDC). The ultraviolet absorption spectrum of dimethyl 4,4 -biphenyldicarboxyl ate was examined in both HFIP and 95% ethanol. In each case two distinct absorption maxima were recorded, an intense absorption near 200 nm and a slightly less intense absorption near 280 nm. The corrected fluorescence excitation and emission spectra of 4,4 -BPDC in HFIP at 298°K shows a single broad excitation band centered at 280 nm with a corresponding broad structureless emission band centered at 340 nm. At 77°K, the uncorrected phosphorescence spectra shows a single broad structureless excitation band centered at 298 nm, and a structured emission band having maxima at 472 and 505 nm with a lifetime, t, equal to 1.2 seconds. 

Diamino-3,3 -biphenyldicarboxylic acid 4,4 -Diaminobiphenyl-3,3 -dicarboxylic acid. See Diaminodiphenic acid 4,4 -Diamino-3,3 -biphenyldiol dimethyl ether. See Dianisidine... 

Biphenyldicarboxylic acid, polyester with ethylene glycol 4,4 -Biphenyldicarboxylic acid, polyester with 1,4-butanediol —, polyester with 2,2 -(2,5-di-ter/-butyl- -phen)denedio3 )diethanol —, polyester with diethylene ycol —, polyester with ethylene glycol —, polyester with 1,6-hexanediol —, 2,2 -dimethyl-, polyester with ethylene ycol Brassylic add. See Tridecanedioic acid. 

The formation of macrocycles may also concern the rigid block. Rozbs [37] prepared liquid crystalline copolymers with flexible blocks of aliphatic polyethers and rigid blocks of aromatic polyesters. They were prepared by polytransesterification of aliphatic diols with aromatic diesters derived from biphenyl or frans-stilbene. Scheme 36 shows the formation of cycles when the diester is dimethyl-2,2 -biphenyldicarboxylate. In this case, the respective location of the ester groups is responsible for the formation of the cyclic compound. 

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