Synthesis and Conformational Study of Optically Active Poly(phenylacetylene) Derivatives Bearing a Bulky Substituent

Amplification of macromolecular helicity of dynamic helical poly(phenylacetylene)s bearing non-racemic alanine pendants in dilute solution, liquid crystal and two-dimensional crystal

“…26 The copolymers poly(1L m -co-1D n ) and homopolymer poly-1L showed a relatively weak induced CD (ICD) in the p-conjugated polymer backbone regions in a dilute benzene solution at 25 1C (Supplementary Figure S2A), compared with those of analogous helical poly(phenylacetylene)s bearing chiral bulky substituents. [27][28][29][30][31][32][33] However, the ICD intensities for poly-1L (Supplementary Figure S2B) and poly(1L m -co-1D n ) with high ee (475%) significantly increased with the decreasing temperature accompanied by a large red-shift in the absorption spectra in benzene, whereas poly(1L m -co-1D n ) with low ee (o50%) showed almost no temperature-dependent CD intensity change (Figures 2A and C, inset), suggesting that almost no amplification of the helical chirality (negative nonlinear effect), induced by the non-racemic monomer units, took place in benzene. …”

Chiral and Chirality Discrimination on Helical Polyacetylenes

“…2). 13 The UV-visible and Synthesis and function of helical polyphenylacetylenes are briefly reviewed.…”

Synthesis and Properties of Substituted Polyacetylenes Having Cyclohexyl Groups

“…Phenylcyclohexane (Wako Pure Chemical), tert-butyldimethylsilyl chloride (Aldrich), p-(trimethylsilyl)phenylacetylene (NOF), trifluoroacetic acid (TFA, Wako Pure Chemical Industries Ltd.), and common solvents were used without further purification except toluene and CCl 4 as polymerization solvents. p-Cyclohexyliodobenzene 18 and p-(tert-butyldimethylsiloxy)phenylacetylene 19 were prepared according to the literature procedure. Monomers 1a-e were synthesized according to Scheme 2, referring to the literature concerning ethynylation and silylation.…”