دورية أكاديمية
Synthesis And Aggregation Of A Conjugated Helical Molecule
| العنوان: | Synthesis And Aggregation Of A Conjugated Helical Molecule |
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| المؤلفون: | Nuckolls, C., Katz, T. J., Katz, G., Collings, Peter J., Castellanos, L. |
| المصدر: | Physics & Astronomy Faculty Works |
| بيانات النشر: | Works |
| سنة النشر: | 1999 |
| المجموعة: | Swarthmore College: Works |
| مصطلحات موضوعية: | Physics |
| الوصف: | Described are an improved method to synthesize helicenebisquinone 1 and an efficient method to resolve its enantiomers and those of other helicenebisquinones by separating derived camphanate esters. The union of p-benzoquinone and the bis(triisopropylsilylenol ether) of a 2,7-diacetyl-4,5-dialkoxynaphthalene gives the helicene skeleton in 56% yield. Molecules of nonracemic 1 aggregate when their dodecane solutions are concentrated to 5 x 10(-4) M or more. Chloroform dissociates the aggregates. Aggregation is characterized by enhanced circular dichroisms and g values, red-shifted UV-vis absorptions, increased specific rotations, increased light scattering at an absorption frequency, and, as reported previously, fluorescence emissions that shift to the red, H-1 NMR resonances that shift upfield, and organization of the pure material into fibers. The CD and UV-vis absorption spectra of spin-coated films are similar to those of concentrated solutions in dodecane, but the g values are higher. The specific rotation of a cast film, [alpha](D), is 158 000 (deg cm(2))/10 g. Unlike the nonracemic material, the racemic in bulk does not form visible fibers and is too insoluble to give concentrated solutions in dodecane. Also nonracemic helicene 3 does not show the characteristics of aggregation either in solution or in bulk. |
| نوع الوثيقة: | text |
| اللغة: | unknown |
| العلاقة: | https://works.swarthmore.edu/fac-physics/133Test |
| DOI: | 10.1021/ja983248l |
| الإتاحة: | https://doi.org/10.1021/ja983248lTest https://works.swarthmore.edu/fac-physics/133Test |
| رقم الانضمام: | edsbas.7108597B |
| قاعدة البيانات: | BASE |
| DOI: | 10.1021/ja983248l |
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