1989 Fiscal Year Final Research Report Summary
Study on Crystal Growth of Metal Complexes by in sitn Observation Method
Project/Area Number |
63470039
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Research Category |
Grant-in-Aid for General Scientific Research (B)
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Allocation Type | Single-year Grants |
Research Field |
無機・錯塩・放射化学
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Research Institution | Okayama University |
Principal Investigator |
YOSHIKAWA Yuzo Okayama University, Faculty of Science Professor, 理学部, 教授 (30022643)
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Project Period (FY) |
1988 – 1989
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Keywords | In sitn observation / Metal complex / Crystal growth / Spiral growth mechanism / Force-field calculation |
Research Abstract |
The handedness of the spirals growth patterns was statistically counted on the (001) faces of the crystal of d- and 1-[Co(ox)(en)_2]Cl.4H_2O in a supersaturated aqueous solution (about 0.13 mol/dm^3; supersaturation ratio, 0.15) in the fluidised cell at 25゚C. There were little difference between the cccurrence-frequencies of the bandedness of the spirals for both the isomers and therefore no correlation between the chirality of complex crystals and the handedness of spirals. It can be considered that the handedness of the large spiral as observed does not reflect the chirality of the molecular and/or crystal structures of the optically-active complexes, but it may be caused by something macroscopic which can be often observed in the center of the spirals. We considered the foreign substance to be a small crystal of the same complex. Furthermore we also found a few double spirals which can be regarded as being simultaneously generated on both the top and bottom surface of the thin plate from the common macroscopic origin. For the same complex bromide, the crossed ridgeline was found, but the spirals could not observed even with the aid of the scanning electron microscope. Although we also tried to find spirals for several cobalt(III) complexes, no spirals was found on the crystals of all the used complexes. The linear crystal growth rate, R can be expressed by R = k.sigma^n, where k is the rate constant for crystal growth, sigma the supersaturation ratio, and n the effective order of reaction which can be empirically determined. In the present in situ observation, the crystal growth rate of the (111) face was measured at 25゚C, which gave about 1.6 for the effective order, n. It can be considered that the crystal growth on the (111) face also proceeds by a spiral growth.
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