Cyclopolymerization of (E,E) ‐ [6.2]paracyclophane‐1,5‐diene

Abstract

synopsisPolymerization of (E,E &[6.2]paracyclophane-l,5diene proceeds by an intra-intermolecular mechanism to give a polymer containing a [3.2]paracyclophane in the repeat unit. Polymerization occurs with either free radical or cationic initiation; anionic initiation was unsuccessful. Cationic polymerization is favored and appears to proceed through a stabilized carbonium ion intermediate. Spectroscopic and model compound studies are consistent with the proposed polymer structure. Thermal analyses of the polymer indicate a complex thermooxidative behavior in the presence of oxygen, while depolymerization occurs above about 4WC in an inert atmosphere.It appeared likely that cyclopolymerization leading to such [3.2]paracyclophane units would be favored in a 1,2-bis(p-vinylphenylkthane structure if the vinyl groups were constrained to lie in close proximity. This proves to be the case. In this paper we describe the ~y n t h e s i s ,~ characterization and properties of cyclopolymer 6 derived from (E,E)-[6.2] paracyclophane-l,5diene (5 1.

Cationic cyclopolymerization of 1,2‐bis(2‐vinyloxyethoxy)benzenes: Introduction of bulky substituents to increase cyclopolymerization tendency

“…Styrenic bifunctional monomers that undergo cyclopolymerization are rather limited, and include bis( p ‐vinylphenyl)alkanes7–10 and para ‐cyclophane‐1,5‐diene 11, 12. In contrast, a number of divinyl ether monomers were reported to undergo cationic cyclopolymerization to form polymers containing cyclized repeating units in the polymer backbones 13, 14.…”

Thermal degradation of poly((E,E)‐[6.2]paracyclophane‐1,5‐diene)

“…Poly ( ( E , E ) -[ 6.21 paracyclophane-l,&diene) , 1, contains aromatic rings with aligned pi systems that facilitate electrical conduction. [4][5][6] As in other [ n.21paracyclophane systems for which n is small, the close proximity of aromatic rings in the [6.2] paracyclophane repeat unit generates significant strain in this Investigations of the thermal decomposition of 1, a photoconductive p~l y m e r ,~ in inert and oxidative atmospheres are presented here.…”

New Type of Donor-Acceptor Through-Space Conjugated Polymer

“…Since [2.2]paracyclophane was first prepared by Brown and Farthing in 1949 [1], [2.2]paracyclophane consisting of two benzene rings closely linked (distance of approximately 2.8-3.1Å) by two ethylene bridges at para positions, it has been attracting attention [2][3][4]. However, even though cyclophane compounds have been receiving considerable attention in the field of organic chemistry, only several reports [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] on the synthesis of [2.2]paracyclophane-containing polymers have been published in the field of polymer chemistry. In particular, only a few reports on conjugated polymers containing [2.2]paracyclophane in the polymer main chain have been published [5][6][7][20][21][22][23].…”