Abstract
Abstract Photodimerization of cocrystals of four bispyridylethylenes and two stilbazoles with urea as a template in the solid state has been investigated following our success with thiourea. Four investigated olefins photodimerized quantitatively to a single dimer in the crystalline state only. The reactivity of urea-olefin crystals is understood on the basis of their packing arrangements in the crystalline state. In reactive crystals the adjacent reactive molecules are within 4.2 Å and parallel, whereas the unreactive ones have their adjacent molecules are farther than 4.6Å and nonparallel. Thus, with the knowledge of crystal packing the reactivity of urea-olefin crystals is predictable on the basis of Schmidt's topochemical postulates. The templating property of urea, similar to thiourea, derives from its ability to form hydrogen bonds with itself and the guest olefins. Despite the similarities in molecular structures of urea and thiourea their subtle electronic properties, yet to be fully understood, affect the crystal packing and consequently their reactivity in the crystalline state. Further work is needed to fully exploit the templating properties of urea. Templating properties of urea in solid-state photodimerization of stilbazoles and bispyridylethylenes have been established through a study that combined photochemistry and X-ray crystallography. The templating ability of urea derives from its ability to form hydrogen bond with itself and with coguests stilbazoles and bispyridylethylenes. At this stage, it is not easy to predict when urea will and when will not function as a template.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 696-704 |
| Number of pages | 9 |
| Journal | Photochemistry and Photobiology |
| Volume | 91 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 1 2015 |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Biochemistry
- Medicine(all)
Cite this
Comparison of templating ablities of urea and thioruea during photodimerization of bipyridylethyelene and stilbazole crystals. / Bhogala, Balakrishna R.; Captain, Burjor; Ramamurthy, Vaidhyanathan.
In: Photochemistry and Photobiology, Vol. 91, No. 3, 01.05.2015, p. 696-704.Research output: Contribution to journal › Article
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TY - JOUR
T1 - Comparison of templating ablities of urea and thioruea during photodimerization of bipyridylethyelene and stilbazole crystals
AU - Bhogala, Balakrishna R.
AU - Captain, Burjor
AU - Ramamurthy, Vaidhyanathan
PY - 2015/5/1
Y1 - 2015/5/1
N2 - Abstract Photodimerization of cocrystals of four bispyridylethylenes and two stilbazoles with urea as a template in the solid state has been investigated following our success with thiourea. Four investigated olefins photodimerized quantitatively to a single dimer in the crystalline state only. The reactivity of urea-olefin crystals is understood on the basis of their packing arrangements in the crystalline state. In reactive crystals the adjacent reactive molecules are within 4.2 Å and parallel, whereas the unreactive ones have their adjacent molecules are farther than 4.6Å and nonparallel. Thus, with the knowledge of crystal packing the reactivity of urea-olefin crystals is predictable on the basis of Schmidt's topochemical postulates. The templating property of urea, similar to thiourea, derives from its ability to form hydrogen bonds with itself and the guest olefins. Despite the similarities in molecular structures of urea and thiourea their subtle electronic properties, yet to be fully understood, affect the crystal packing and consequently their reactivity in the crystalline state. Further work is needed to fully exploit the templating properties of urea. Templating properties of urea in solid-state photodimerization of stilbazoles and bispyridylethylenes have been established through a study that combined photochemistry and X-ray crystallography. The templating ability of urea derives from its ability to form hydrogen bond with itself and with coguests stilbazoles and bispyridylethylenes. At this stage, it is not easy to predict when urea will and when will not function as a template.
AB - Abstract Photodimerization of cocrystals of four bispyridylethylenes and two stilbazoles with urea as a template in the solid state has been investigated following our success with thiourea. Four investigated olefins photodimerized quantitatively to a single dimer in the crystalline state only. The reactivity of urea-olefin crystals is understood on the basis of their packing arrangements in the crystalline state. In reactive crystals the adjacent reactive molecules are within 4.2 Å and parallel, whereas the unreactive ones have their adjacent molecules are farther than 4.6Å and nonparallel. Thus, with the knowledge of crystal packing the reactivity of urea-olefin crystals is predictable on the basis of Schmidt's topochemical postulates. The templating property of urea, similar to thiourea, derives from its ability to form hydrogen bonds with itself and the guest olefins. Despite the similarities in molecular structures of urea and thiourea their subtle electronic properties, yet to be fully understood, affect the crystal packing and consequently their reactivity in the crystalline state. Further work is needed to fully exploit the templating properties of urea. Templating properties of urea in solid-state photodimerization of stilbazoles and bispyridylethylenes have been established through a study that combined photochemistry and X-ray crystallography. The templating ability of urea derives from its ability to form hydrogen bond with itself and with coguests stilbazoles and bispyridylethylenes. At this stage, it is not easy to predict when urea will and when will not function as a template.
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U2 - 10.1111/php.12353
DO - 10.1111/php.12353
M3 - Article
C2 - 25263180
AN - SCOPUS:84928660829
VL - 91
SP - 696
EP - 704
JO - Photochemistry and Photobiology
JF - Photochemistry and Photobiology
SN - 0031-8655
IS - 3
ER -