A Versatile Palladium-Catalyzed Synthesis of n-Alkyl-Substituted Oligo-p-phenyls
作者:Patrick Galda、Matthias Rehahn
DOI:10.1055/s-1996-4260
日期:1996.5
High-yield Pd-catalyzed syntheses of constitutionally homogeneous, n-alkyl-substituted oligo-p-phenyls having three to fifteen benzene rings connected to each other exclusively in the 1,4-(para-) fashion are reported. Most of the oligomers described readily dissolve in common organic solvents. Furthermore, their thermal phase-transition temperatures show that some of these rodlike oligomers can exist in different crystalline modifications and/or form liquid-crystalline mesophases.
Chiral Studies in Amorphous Solids: The Effect of the Polymeric Glassy State on the Racemization Kinetics of Bridged Paddled Binaphthyls
作者:Ji-Woong Park、Mark D. Ediger、Mark M. Green
DOI:10.1021/ja0023231
日期:2001.1.1
function of temperature. The racemization occurs by a simple one-dimensional twisting motion and, without effect on the intrinsic mechanism, sweeps out a variable volume of the matrix as the paddle length is increased. The racemization is limited by the polymer matrix only for probes with a minimum paddle size and only when the timescale for racemization is comparable to the timescale for segmental