Tunable Columnar Mesophases Utilizing C2 Symmetric Aromatic Donor-Acceptor Complexes
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- 作者：Joseph J. Reczek ; Karen R. Villazor ; Vincent Lynch ; Timothy M. Swager ; and Brent L. Iverson
- 刊名：Journal of the American Chemical Society
- 出版年：2006
- 出版时间：June 21, 2006
- 年：2006
- 卷：128
- 期：24
- 页码：7995 - 8002
- 全文大小：723K
- 年卷期：v.128,no.24(June 21, 2006)
- ISSN：1520-5126
文摘
Derivatives of relatively electron rich 1,5-dialkoxynaphthalene (Dan) donors and relatively electrondeficient 1,4,5,8-naphthalenetetracarboxylic diimide (Ndi) acceptors have been exploited in the folding andself-assembly of a variety of complex molecular systems in solution. Here, we report the use of Dan andNdi derivatives to direct assembly of extended columns with alternating face-centered stacked structure inthe solid state. A variety of 1:1 Dan:Ndi mixtures produced mesophases that were found to be stable overtemperature ranges extending up to 110 
C. Analysis of these mesophases indicates mixtures with soft/plastic crystal phases and a few mixtures with the thermodynamic properties of true liquid crystals, allcomposed of alternating donor-acceptor columns within. Importantly, a correspondence was found betweenthe clearing and crystallization points of the mesophase mixtures and the melting/clearing points of thecomponent Ndi and Dan units, respectively. This correspondence enables the predictable tuning ofmesophase phase transition temperatures. The study of sterically hindered derivatives led to a set of mixturesin which a dramatic and sudden color change (deep red to yellow) was observed upon crystallization ofthe mesophase due to a phase separation of the component donor and acceptor units.
C. Analysis of these mesophases indicates mixtures with soft/plastic crystal phases and a few mixtures with the thermodynamic properties of true liquid crystals, allcomposed of alternating donor-acceptor columns within. Importantly, a correspondence was found betweenthe clearing and crystallization points of the mesophase mixtures and the melting/clearing points of thecomponent Ndi and Dan units, respectively. This correspondence enables the predictable tuning ofmesophase phase transition temperatures. The study of sterically hindered derivatives led to a set of mixturesin which a dramatic and sudden color change (deep red to yellow) was observed upon crystallization ofthe mesophase due to a phase separation of the component donor and acceptor units.