2496-27-7

Upstream product

• 4469-80-1 4-propoxyaniline 
• 108-95-2 phenol 
• 100-02-7 4-nitro-phenol 
• 7244-77-1 1-nitro-4-propoxybenzene 

Downstream Products

• 1616081-59-4 {4-[(4-propoxyphenyl)-ONN-azoxy]phenoxy}acetonitrile 
• 1616081-60-7 {4-[(4-propoxyphenyl)-NNO-azoxy]phenoxy}acetonitrile 

Relevant academic research and scientific papers

Dual thermo- and light-responsive nanorods from self-assembly of the 4-propoxyazobenzene-terminated poly(N-isopropylacrylamide) in aqueous solution

Abstract Both temperature and light stimuli-responsive 4-propoxyazobenzene-terminated poly(N-isopropylacrylamide)s (PNIPAMs) were successfully synthesized by the atom transfer radical polymerization (ATRP) of NIPAM. 1H NMR and UV-vis absorption spectra indicated rapid photoisomerization rate of 4-propoxyazobenzene moiety. Interestingly, the lower critical solution temperature (LCST) for PNIPAM aqueous solution clearly decreased after UV irradiation, and the repeated LCST difference (ΔTmaxy = 5°C) depended on both the number-average molecular weight and amount of azobenzene chromophore. Dynamic light scattering (DLS) and static light scattering (SLS) measurements showed that the PNIPAM aqueous solution could self-assemble into nano-micelles with 4-propoxyazobenzene as the hydrophobic cores and PNIPAM chains as the hydrophilic shells. UV irradiation induced the increase of particle size due to the formation of much looser cores of cis-azobenzene. TEM images showed the presence of both nanorods and spherical micelles. After UV irradiation, the unstable spherical micelles transformed to metastable nanorods, then to longer rods, and finally the longer rods began to transform to flake-like particles via horizontal inter-rod aggregation above LCST.

Synthesis, mesomorphic and dielectric properties of 4-(cyanomethoxy)phenyl 4-alkoxybenzoates, 4-(cyanomethoxy)-4′-alkoxyazo- and -azoxybenzenes

Preparation methods were developed for homologs of 4-(cyanomethoxy)phenyl 4-alkoxybenzoates (C7, C8, C9), 4-(cyanomethoxy)-4′-alkoxyazo (C2, C3, C 6), -azoxybenzenes (C3, C6) whose composition and structure were proved by elemental analysis and 1H NMR spectra. 4-(Cyanomethoxy) group destabilizes the mesophase, consequently, only four among the compounds obtained exhibit the thermotropic nematic mesomorphism.

Liquid crystalline properties of azobenzenes: I. 4-methoxy-, 4-ethoxy-, 4-propoxy-and 4-butoxy-4′-alkyloxyazobenzenes

Liquid crystalline properties of four series of azobenzenes, 4-methoxy-4-alkyloxyazobenzenes (azo-1-n), 4-ethoxy-4′-alkyloxyazobenzenes (azo-2-n), 4-propoxy-4′al-kyloxyazobenzenes (azo-3-n) and 4-butoxy-4′-alkyloxyazobenzenes (azo-4-n), were investigated. By polarizing microscopy nematic and smectic C mesophases were detected. By DSC and TOA thermo-optics the parameters of phase transitions were measured. A typical odd-even effect of the clearing temperature was found. No smectic phase was detected in the first three series, even for the longest alkyloxy chains. The smectic C appears for the first time in the butoxy family, starting from the undecyloxyl derivative. In each series a polymorphism in the solid state was detected, especially significant in the propoxy and butoxy family, that was explained in terms of the ODIC phases.

Side-Chain Liquid-Crystalline Polyoxetanes with a Spacer-Separated Azobenzene Moiety. II. Preparation and Characterization of Polyoxetanes Derived from 4-(4-Alkoxyphenylazo)phenyl 4-[7-(3-Methyl-3-oxetanyl)-1,6-dioxaheptyl]-benzoates

A series of polyoxetanes were prepared by the cationic ring-opening polymerization of 4-(4-alkoxyphenylazo)phenyl 4-[7-(3-methyl-3-oxetanyl)-1,6-dioxaheptyl]benzoates using 0.08 molar amount of THF·BF3 in dichloromethane at 20 to 30° C. Although the product polymers indicated GPC-average molecular weights of around 9000 to 23000, in most cases, they did not have an unimodal molecular weight dispersity. The liquid-crystalline mesophases of the polymers were examined by differential scanning calorimetry and polarized optical microscopy; these textures were observed due to nematic and/or smectic mesophases over a wide temperature range from about 250° C to room temperature. The benzoate moiety, the longer p-substituted alkoxy tails, and the oxetane main chain play important roles in maintaining highly ordered, stable mesophases.

Mesogenic 4-(2,3-Epoxypropoxy)-4'-alkoxyazoxybenzenes

Optimal conditions for preparation of 4-(2,3-epoxypropoxy)-4'-alkoxyazoxybenzenes were developed, and 10 mesogenic homologs (n = 1-10) possessing an extended nematic mesophase were synthesized.Nonyloxy and decyloxy derivatives of epoxyazoxybenzene exhibit also smectic mesomorphism.

Mesogenic properties of liquid crystals having a chiral semiflexible joint

Two homologous series of mesogenic enantiomers with chiral semiflexible joint, -C*H(CH3)CH2COO-, are examined. High twist power and presence of blue phases with short lattice period are found for eleven examined compounds. Some effects of chirality in reentrant system are discussed. On phase diagram of enantiomers the SmAd phase area is shifted toward longer homologues as compared to racemates. In result, an island of the SmAd phase in the cholesteric sea exists on binary phase diagrams of R- and S- enantiomers. Triple divergence of the pitch in the cholesteric phase of a pure compound is observed.