Preparation of amphotropic liquid crystalline poly(alkoxycarbonylphenylene)s

Abstract

SUMMARY: Poly(alkoxycarbonylphenylene)s with long alkoxy groups were prepared by dehalogenative polycondensation of alkyl dichlorobenzoates with nickel bromide/zinc/triphenylphosphine catalyst. The poly(alkoxycarbonyl-p-phenylene)s and poly(alkyloxycarbonyl-m-phenylene)s are liquid crystalline, although the latter are composed wholly of kinked repeating units. While poly(hexyloxycarbonylphenylene)s exhibit only thermotropic liquid crystalline behavior, poly(dodecyloxycarbonylphenylene)s and poly(hexadecyloxycarbonylphenylene)s show amphotropism.

Poly(pyridinium salt)s with organic counterions derived from an aromatic diamine containing tetraoxyethylene units exhibiting amphotropic liquid‐crystalline and photoluminescence properties

“…They are the novel members of a class of poly(pyridinium salt)s with various organic counterions that exhibited both lyotropic and thermotropic liquid‐crystalline properties, which can be classified as amphotropic polymers. Although the literature is replete with many lyotropic (solvent induced) and many thermotropic (heat induced) liquid‐crystalline polymers,42 relatively few amphotropic liquid‐crystalline polymers both neutral and ionic polymers exist to date 7, 8, 31, 43–46…”

Nickel-Catalyzed Cross-Couplings Involving Carbon−Oxygen Bonds

“…The highest DP was achieved with a monomer feed ratio of 75% methyl 2,5-bis[(methylsulfonyl)oxy]benzoate and 25% 2-ethylhexyl 2,5-bis[(methylsulfonyl)oxy]benzoate. Similar liquid crystalline poly(alkoxycarbonyl- m -phenylene)s and poly(alkoxycarbonyl- p -phenylene)s were prepared through similar Ni 0 -catalyzed polycondensations of alkoxy 2,5- and 3,5-dichlorobenzoates . The Ni 0 -catalyzed polycondensation was tolerant of a broad array of bismesylate monomers (Scheme ).…”

Self-Assembled Helical Conjugated Poly(m-phenylene) Derivatives That Afford Whiskers with Hexagonal Columnar Packed Structure

“…The stereochemistry of the chiral alcohol of the resulting precursor changes into the opposite configuration through a Walden’s inversion in an S N 2 reaction. Polymerizations of the precursors were carried out at 100 °C in N,N -dimethylformamide using Ni(COD) 2 to give the corresponding poly( m -phenylene) derivatives [ P1 , P2 , P3 , ( R ) -PMP and ( S ) -PMP ] with good yields (89–99%) . Here it should be noted that strictly speaking, ( R )- and ( S )- PMP have homochiral side chains and P2 and P3 have stereochemically random side chains with no optical activity.…”