MISC

2005年9月

Modified photoreactivity due to mixed crystal formation. III. Decelerated photoisomerization upon topochemically unfavorable conformational change

CRYSTAL GROWTH & DESIGN
  • C Vithana
  • ,
  • H Uekusa
  • ,
  • A Sekine
  • ,
  • Y Ohashi

5
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
DOI
https://doi.org/10.1021/cg0495633
CiNii Articles
http://ci.nii.ac.jp/naid/80017503058
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000231767400020&DestApp=WOS_CPL
ID情報
  • DOI : 10.1021/cg0495633
  • ISSN : 1528-7483
  • CiNii Articles ID : 80017503058
  • Web of Science ID : WOS:000231767400020

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