The prehistory of discotic mesophases – a personal account of the study of the mesophase of diisobutylsilane diol

Abstract

This is an account of the study of the strange little mesogen, diisobutylsilane diol, at Leeds in the 1970s and the role which George Gray played in the story. Even in those early days George imposed a quiet authority on the subject. In both Britain and abroad, people listened to him and valued his opinions and judgment. He steadily assumed the elder statesman role in the British liquid crystal world. He was always accessible and ready to help people like me who were not in his own research group.

Acknowledgements

Personal accounts of this kind tend to be unreliable, selective and biased – and I have therefore endeavoured to check that my recollections of these events tally with those of the other people concerned – and I am especially grateful to Professor John Goodby for his help in preparing this article.

I acknowledge the fine experimental work of my research students, John Bunning and Paul Tomlins. I thank Professor Richard Bushby for his advice and help (both then and now).

References

This material was presented as a lecture at a British Liquid Crystal Society some years ago [i] and has been published recently, in a slightly different form, in Liquid Crystals Today [ii].

[i] Lydon, J. (2007) The prehistory of discotic phases: Carbonaceous Phases and Diisobutylsilane Diol, Invited lecture given at the British Liquid Crystal Society annual conference, Sheffield.

[ii] Lydon, J. (2014) The prehistory of discotic mesophases – a personal account of the study of the mesophase of diisobutylsilane diol, Liquid Crystals Today 01/2014; 23(1).

Notes

1. At this time, I was not aware of the full weight of authority denying the existence of small molecule discotic phases. Vorländer had famously stated:

‘It is true that one could think that flake-like molecules can be so arranged, superimposed with each molecule’s face lying on each other’s, in a packing resembling a Volta’s pile-like structure so that anisotropic structures are generated. The results of our investigations, however are against this hypothesis’.[24]

2. To some extent, this confusion still exists. Both the focal conic texture of smectic phases and the developable domain discotic texture are routinely described as having a ‘fan-shaped texture’.

3. On reflection, perhaps my elation was not justified – and the miscibility criterion, which has proved so useful in classifying smectic phases does not work for discotics. And, paradoxically, in this particular case, it could be the immiscibility of the molecules within a stack which enables the columns to coexist within a mixed phase – without the disruptive effect of alien molecules entering the columns.