Title | Tunable columnar mesophases utilizing C2 symmetric aromatic donor-acceptor complexes. |
Publication Type | Journal Article |
Year of Publication | 2006 |
Authors | Reczek, JJ, Villazor, KR, Lynch, V, Swager, TM, Iverson, BL |
Journal | Journal of the American Chemical Society |
Volume | 128 |
Pagination | 7995–8002 |
Date Published | jun |
ISSN | 0002-7863 |
Keywords | Biomimetic Materials, Biomimetic Materials: chemistry, Crystallization, Crystallography, Electrons, Imides, Imides: chemistry, Liquid Crystals, Liquid Crystals: chemistry, Molecular Conformation, Naphthalenes, Naphthalenes: chemistry, Phase Transition, Thermodynamics, X-Ray, X-Ray Diffraction |
Abstract | Derivatives of relatively electron rich 1,5-dialkoxynaphthalene (Dan) donors and relatively electron deficient 1,4,5,8-naphthalenetetracarboxylic diimide (Ndi) acceptors have been exploited in the folding and self-assembly of a variety of complex molecular systems in solution. Here, we report the use of Dan and Ndi derivatives to direct assembly of extended columns with alternating face-centered stacked structure in the solid state. A variety of 1:1 Dan:Ndi mixtures produced mesophases that were found to be stable over temperature ranges extending up to 110 degrees C. Analysis of these mesophases indicates mixtures with soft/plastic crystal phases and a few mixtures with the thermodynamic properties of true liquid crystals, all composed of alternating donor-acceptor columns within. Importantly, a correspondence was found between the clearing and crystallization points of the mesophase mixtures and the melting/clearing points of the component Ndi and Dan units, respectively. This correspondence enables the predictable tuning of mesophase phase transition temperatures. The study of sterically hindered derivatives led to a set of mixtures in which a dramatic and sudden color change (deep red to yellow) was observed upon crystallization of the mesophase due to a phase separation of the component donor and acceptor units. |
URL | http://www.ncbi.nlm.nih.gov/pubmed/16771514 |
DOI | 10.1021/ja061649s |