Conducting mesomorphic polypyrroles

Pyrrole and polypyrrole-based liquid crystals containing azobenzene mesogenic groups

“…As part of this research effort, and in the continuing search for conducting liquid crystal polymers, much interest has been directed at thiophene and particularly at pyrrole-based systems. [2][3][4][5][6][7][8][9][10][11][12][13] In our studies focussed on pyrrole systems we have sought to investigate the influence of molecular structure on the thermotropic behaviour of the monomer species and to channel this understanding into the design and fabrication of liquid crystal polymer materials. Our research has centred on the attachment, via an alkyl chain, of a mesogenic group to the N-site of the pyrrole ring to yield mesogenic monomers and the subsequent polymerisation of these to give side group liquid crystal polymers based on a conducting pyrrole backbone.…”

“…Despite the growing number of studies on pyrrole-based liquid crystals, [2][3][4][5][6][7][8][9][10][11][12][13] there is no clear understanding of how molecular structure effects the mesogenic behaviour in this class of materials which are very different in nature to conventional low molar mass liquid crystals. In this respect we have undertaken a systematic study of monomeric molecular species.…”

Pyrrole- and polypyrrole-based liquid crystals

“…Although significant progress has been made in the synthesis of soluble/processable polymer systems by other research groups recently, 1 for example, by grafting long chain alkyl groups on to the pyrrole or thiophene ring, there remain very few examples of conducting polymer systems that exhibit liquid crystal phases. 2,3 Of particular interest, however, has been the development of pyrrole-based liquid crystalline systems [4][5][6][7][8][9][10][11][12][13] and here we describe the synthesis and characterisation of pyrrolebased monomers substituted at the N-position with the mesogenic group 4-cyanobiphenyl. We discuss the spectroscopic and thermotropic properties of these monomers and describe their oxidative polymerisation using electrochemical methods and separately using FeCl 3 and I 2 as chemical oxidants.…”

Synthesis and Properties of a Novel Thiophene‐Based Conducting Copolymer with Mesogenic Groups Attached Parallel to the Polymer Backbone

“…[1][2][3][4][5][6] However, only one piece of work appears to have been reported in which the mesogenic group is attached parallel to the conducting polymer backbone with the liquid-crystal director also parallel to the conducting polymer backbone, as illustrated in Figure 1b; this is limited to a 3-substituted polypyrrole. [7] In this work we report the synthesis of the first example of a polythiophene that is substituted at the 3-position with the mesogenic group attached parallel or side-on to the conducting thiophene polymer backbone by a flexible spacer. The long-term aim of this work is to determine how orientation of the mesogens relative to the polymer backbone can affect the conductivity of these interesting materials utilising a variety of alignment techniques.…”

“…A significant amount of work has now been reported on a wide range of conducting polymers in which the mesogenic group is terminally attached by a flexible spacer to the conducting polymer backbone, with the liquid‐crystal director aligned orthogonally to the polymer backbone, as shown in Figure 1a 1–6. However, only one piece of work appears to have been reported in which the mesogenic group is attached parallel to the conducting polymer backbone with the liquid‐crystal director also parallel to the conducting polymer backbone, as illustrated in Figure 1b; this is limited to a 3‐substituted polypyrrole 7. In this work we report the synthesis of the first example of a polythiophene that is substituted at the 3‐position with the mesogenic group attached parallel or side‐on to the conducting thiophene polymer backbone by a flexible spacer.…”