Document Detail


Transformation of Kinetically into Thermodynamically Controlled Self-Organization of Complex Helical Columns with 3D Periodicity Assembled from Dendronized Perylene Bisimides.
MedLine Citation:
PMID:  23406582     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
The dendronized perylene 3,4:9,10-tetracarboxylic acid bisimide (PBI), (3,4,5)12G1-1-PBI was reported by our laboratory to self-assemble into complex helical columns containing dimers of dendronized PBI with one molecule in each stratum, different intra- and interdimer rotation angles but identical intra- and interdimer distance of 3.5Å, exhibiting a four-strata 21 helical repeat. A thermodynamically controlled 2D columnar hexagonal phase with short-range intracolumnar order represents the thermodynamic product at high temperature while a kinetically controlled monoclinic columnar array with 3D periodicity is the thermodynamic product at low temperature. With heating and cooling rates higher than 10 ºC/min to 1 ºC/min, at low temperature the 2D columnar periodic array is the kinetic product for this dendronized PBI. Here the synthesis and structural analysis of a library of (3,4,5)nG1-m-PBI with n = 12 to 6 and m = 1 are reported. A combination of differential scanning calorimetry, x-ray diffraction on powder and orientated fibers, including pattern simulation and electron density map reconstruction, solid state NMR, all as a function of temperature and heating and cooling rate, was employed for their structural analysis. It was discovered that at low temperature the as prepared n = 12 to 10 exhibit a 3D layered array that transforms irreversibly into columnar periodicities during heating and cooling. Also the kinetically controlled 3D columnar phase of n = 12 becomes thermodynamically controlled for n = 10, 9, 8, 7 and 6. This unprecedented transformation is expected to facilitate the design of functions from dendronized PBI and other self-assembling building blocks.
Authors:
Virgil Percec; Hao-Jan Sun; Pawaret Leowanawat; Mihai Peterca; Robert Graf; Hans W Spiess; Xiangbing Zeng; Goran Ungar; Paul A Heiney
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-2-14
Journal Detail:
Title:  Journal of the American Chemical Society     Volume:  -     ISSN:  1520-5126     ISO Abbreviation:  J. Am. Chem. Soc.     Publication Date:  2013 Feb 
Date Detail:
Created Date:  2013-2-14     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7503056     Medline TA:  J Am Chem Soc     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
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