2005年9月
Modified photoreactivity due to mixed crystal formation. III. Decelerated photoisomerization upon topochemically unfavorable conformational change
CRYSTAL GROWTH & DESIGN
- ,
- ,
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- 巻
- 5
- 号
- 5
- 開始ページ
- 1755
- 終了ページ
- 1760
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1021/cg0495633
- 出版者・発行元
- AMER CHEMICAL SOC
The cobaloxime complexes of (2-cyanoethyl)(aniline)dimethylglyoximatocobalt(III) and (2-cyanopropyl)(aniline)dimethylglyoximatocobalt(III) formed mixed crystals with (4-cyanobutyl)(aniline)dimethylglyoximatocobalt(III), Mix-I and Mix-II, respectively, although the component molecules have considerably different structures. The conformations of Co-C-C-CN of the 2-cyanoethyl and 2-cyanopropyl groups in the respective pure crystals are gauche, but they changed to trans in the mixed crystals. Because the conformations of Co-C-C-C and C-C-C-CN of the 4-cyanobutyl group are trans in both the pure crystal and the mixed crystals, structural mimicry or conformational adoption occurred at the Co-C-C-CN group of each minor component in the mixed crystal formation. The 2-cyanoethyl and 2-cyanopropyl groups of the cobaloxime complexes were isomerized to 1-cyanoethyl and 1-cyanopropyl groups on exposure to a xenon lamp. The isomerization rates were estimated from the changes of the FT/IR spectra. The rate constants of the two groups in both pure crystals and mixed crystals were calculated assuming first-order kinetics. Since the conformations of the reactive 2-cyanoethyl and 2-cyanopropyl groups were changed to topochemically unfavorable trans conformations on mixed crystal formation, the rate constants of isomerization of the 2-cyanoethyl and 2-cyanopropyl groups in the Mix-I and Mix-II crystals, were reduced to about one-third and one-fourth of the original values, respectively, compared to the corresponding rates in the pure crystals.
- リンク情報
- ID情報
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- DOI : 10.1021/cg0495633
- ISSN : 1528-7483
- CiNii Articles ID : 80017503058
- Web of Science ID : WOS:000231767400020