1993 Fiscal Year Final Research Report Summary
CHARACTERIZATION OF PHOTOREACTION PRODUCTS AND PHOTOREACTION MECHANISM
| Project/Area Number |
03640521
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
無機・錯塩・放射化学
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| Research Institution | KOCHI UNIVERSITY |
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Principal Investigator |
YASUI Takaji KOCHI UNIVERSITY,FACULTY OF SCIENCE,PROFESSOR, 理学部, 教授 (20028161)
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| Project Period (FY) |
1991 – 1993
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| Keywords | COBALT(III) COMPLEX / DIAMINODICARBOXYLIC ACID COMPLEX / OPTICALLY ACTIVE COMPLEX / PYOTOLYSIS / CARBON-13 NMR / CIRCULAR DICHROSIM / X-RAY ANALYSIS |
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| Research Abstract |
The cobalt (III) complexes (alpha, beta-1, and beta-2 [Co(eddp)(en)X, beta-[Co(tndp)(en)X, and alpha-[Co(Me_2eddp)(en)]X) containing diaminodicarboxylates [^-OCOCH_2CH_2NR(CH_2) nNRCH_2CH_2COO^- : eddp(R=H, n=2) ; tndp (R=H, n=3) ; Me_2eddp (R=CH_3, n=2)] as quadridentate ligands and ethylenediamine [NH_2CH_2CH_2NH_2 : en] as a bidentate ligand were newly prepared and optically resolved. The geometrical structures and absolute configurations were determined on the basis of the absorption, CD, C-13 NMR spectral date and the crystallographic date.
The aqueous solution of racemic and optically active complexes were irradiated by a 400W high-pressure mercury lamp (internal irradiating lamp) at ca, 5ﾟC for 40-60 min. The resulted solution were column-chromatographed and the desired complexes containing cobalt(III)-carbon bond were obtained from orange and purple eluates. The C-13 NMR spectra of these orange and purple complexes exhibited characteristic resonance peaks at very high magnetic field (at ca.-5 ppm), which are assigned to the carbanion-carbon coordinated to a cobalt(III) ion.
The geometrical structures and absolute configurations of the optically active complexes containing Co-C bond were determined on the basis of the absorption, CD, C-13 NMR spectral date and the crystallographi date. The photolyses of the optically active LAMBDA-alpha, LAMBDA-beta-1, and LAMBDA-beta-2 [Co(eddp)(en)]X produced stereospecifically Co-C bond isomers having LAMBDA-alpha, DELTA-alpha, and LAMBDA (or DELTA)-beta configurations, respectively, and the photolyses of DELTA-beta-[Co(tndp)(en)]X and LAMBDA-alpha-[Co(Me_2eddp)(en)]X produced LAMBDA (or DELTA)-beta and LAMBDA-alpha Co-C bond isomers, respectively.
The present results suggested that the photodecarboxylation occurred stereospecifically on one of the two carboxy1 groups of the coordinated diaminodicarboxyate.
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