EDA complex stability constants and formation enthalpies in a binary liquid crystalline system with induced smectic phase

✍ Scribed by Prof. Dr. habil. D. Demus; Dr. A. Hauser; Dr. G. Pelzl; U. Böttger; S. Schönburg

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 413 KB
• Volume: 20
• Category: Article
• ISSN: 0232-1300
• DOI: 10.1002/crat.2170200314

✦ Synopsis

LII t h e birrary systeiii 4,4'-bis-[n-l~utyla1iii~io]-biphenyl/4-(Z,Z-dicyano-et~ie1~~ l)-plieiiyl 4-11-nonyloxybenzoate which due to EDA coniplex formation exhibits a n induced SA phase, nieasurernents o f t h e charge transfer band, the molar voluniina and transition enthalpies were done. By t h e concentration a n d teniperature dependence, resp., of t h e charge transfer absorption and t h e strongly negative excess voluinina we estimated t h e stability constant and t h e foriiiation enthalpy of t h e coniplex.

The d a t a obtained by the two independent iiiethods agree sufficiently.

J in biniiren

System 4,4'-Bis-[n-but~lainino]-biphenyl/4-n-N01~yloxyl;eii~~~~ii~ire-[4-(2,2-tlicyan-ethenyl)-phenylester], welches infolge EDA-Kornplexbildung eine induzierte SA-l'hase zeigt, wurden die Charge-Transfer-Rande, Molvolumina und Umwantllungsenthalpien gemessen. Aus der Konzentrations-bzw. Temperaturabhangigkeit der Charge-Transfer-Absorption und der stark negativen XxzeBvolumina ermittelten wir die Stabilitatskonstante und die Bildungsenthalpie des Komplexes. Die aus den beiden unabhangigen Methotlen erhaltenen Werte stirninen hinreichend iiherein.