Synthesis and characterization of optically active copolymers of acenaphthylene. 1. Preparation and characterization

Abstract

Optically active copolymers of acenaphthylene ( 1) with (-)-menthyl acrylate ( 2) and (-)-menthyl methacrylate (3) were prepared by free radical initiation in benzene at 70 °C. Reactivity ratios, mean sequence length, and distribution of monomeric units estimated for both copolymer series indicate the formation of quasi-random copolymers, with a higher tendency to blockiness for 1 units. UV and NMR spectra are entirely consistent with these observations and typical signals of strongly interacting aromatic moieties can be identified in the UV short-wavelength region and in the NMR aromatic proton region, respectively. Infrared absorption properties of acenaphthylene homopolymer and copolymers indicate a preferential trans-disyndiotactic configuration of the aromatic unit.

Intramolecular excimer formation in copolymers of methylmethacrylate and indene

“…This behaviour has previously been reported as resulting from the interaction between near rings which brings about a change in microenvironment polarity 26. In other copolymers, for which sequences of chromophore units can be expected, the maximum absorption peaks are blue shifted with respect to homopolymer, and gradually become closer when going from lower to higher chromophore contents 25…”

“…In copolymers where a sequence of aromatic units occurs, the existence of the upfield signals (shoulders between 6 and 7 ppm) can be observed with a relative intensity that increases with the aromatic unit content 25. However, for our copolymers, the aromatic signal does not present any shoulder.…”

Synthesis and characterization of optically active copolymers of acenaphthylene. 2. Chiroptical and fluorescence properties

“…Preparation of the polymer samples was described in part l. 19 The same notation is maintained here, and in Tables I and some pertaining data are collected.…”

“…In the present paper are reported the results obtained in the investigation of the chiroptical and fluorescence emission properties of two series of copolymers of acenaphthylene (1) with (-)-menthyl acrylate ( 2) and (-)-menthyl methacrylate (3), whose preparation has been already described in a previous paper. 19 The investigated properties are related to chemical composition and distribution of monomeric units in the copolymer.…”