Multiple Interactions in the Self-Association of Porphyrin Discotic Mesogens

Autor:	Dolores Velasco, Antoni Segade, Francisco López-Calahorra
Rok vydání:	2008
Předmět:	Stereochemistry Liquid crystalline Intermolecular force Stacking Porphyrin Surfaces Coatings and Films chemistry.chemical_compound Crystallography Monomer chemistry Materials Chemistry Proton NMR Pi interaction Physical and Theoretical Chemistry Spectroscopy
Zdroj:	The Journal of Physical Chemistry B. 112:7395-7402
ISSN:	1520-5207 1520-6106
DOI:	10.1021/jp800475f
Popis:	The conformational preferences and the self-associational behaviors of two hemin-derived porphyrin compounds, a tetramethyl ester and a liquid crystalline tetrakis(3,5-didodecyloxyphenyl)ester, have been studied by UV/vis and (1)H NMR spectroscopy in solution. Results indicate that the 3,5-didodecyloxyphenyl units play an important role in both the conformational and the self-associational behaviors of the mesomorphic tetraester. In the monomeric, nonassociated species, the two propionic 3,5-didodecyloxyphenyl esters establish mutual CH/pi interactions that restrict the fluctuative behavior of the chains. In the dimeric, self-associated species, intermolecular CH/pi interactions occur in addition to the pi-pi stacking of the porphyrin cores. The temperature-dependent addition of side CH/pi interactions to the pi-pi stacking of the porphyrin rings accounts for the observed tightening and for the slower dynamics of the dimeric structure. The relationship between the self-associational behavior and the mesomorphism of the hemin-derived porphyrin tetraesters is also discussed.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4a29b0fb8e12124754890d50d093b15f https://doi.org/10.1021/jp800475f Zobrazit plný text záznamu