کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1328079 | 977534 | 2007 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Synthesis, computational modelling and liquid crystalline properties of some [3]ferrocenophane-containing Schiff’s bases and β-aminovinylketone: Molecular geometry–phase behaviour relationship Synthesis, computational modelling and liquid crystalline properties of some [3]ferrocenophane-containing Schiff’s bases and β-aminovinylketone: Molecular geometry–phase behaviour relationship](/preview/png/1328079.png)
Rotationally fixed [3]ferrocenophane extends the variety of possible molecular geometries in its derivatives in comparison with unbridged ferrocenes. In this respect molecular geometry–liquid crystalline properties relationship studies in [3]ferrocenophane mesogens are of considerable interest. Different positional isomers of mono- and di-substituted [3]ferrocenophanes which are obtained by incorporating one or two promesogenic building blocks into the cyclopentadienyl rings are reported in this article. A series of mono-substituted [3]ferrocenophane-containing Schiff’s bases was synthesized by condensing isomeric p-aminophenyl [3]ferrocenophanes with appropriate aldehydes. Isomers of di-substituted [3]ferrocenophane amines gave rise to a series of azomethines with two promesogenic substituents in the cyclopentadienyl rings. Besides, a β-enaminoketone was prepared from 3-(p-aminophenyl)[3]ferrocenophane. Nematic and smectic mesophases were observed in the synthesized compounds under a polarizing optical microscope. The [3]ferrocenophane-containing β-enaminoketone showed complex mesomorphic behaviour connected with occurrence of the keto-enamine and imino-enol tautomeric equilibrium in this compound. On the base of computational models obtained by semi-empirical quantum chemistry calculations the molecular geometry–phase behaviour relationships were examined. It was demonstrated that mesomorphism of [3]ferocenophane azomethines depends on the spatial orientation of the substituents with respect to the propanediyl bridge in a case of mono-, and as well as to each other in a case of di-substituted derivatives.
Syntheses of series of mono- and di-substituted [3]ferrocenophane derivatives with various promesogenic molecular shapes are reported in this article. Nematic and smectic mesophases were observed in the synthesized compounds. On the base of computer-generated molecular models the molecular geometry–phase behaviour relationships were examined.Figure optionsDownload as PowerPoint slide
Journal: Journal of Organometallic Chemistry - Volume 692, Issue 25, 1 December 2007, Pages 5571–5582