1997 Fiscal Year Final Research Report Summary
Theoretical Study of the electronic Structure of Three Bridged Binuclear Complex Ion M_2Cl_9^<3・> : M=Cr, Mo, W
| Project/Area Number |
07640668
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | The University of Electro-Communications |
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Principal Investigator |
TANAKA Kiyoshi The University of Electro-Communications, Faculty of Electro-Communications, Professor, 電気通信学部, 教授 (00000860)
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| Co-Investigator(Kenkyū-buntansha) |
MIYOSHI Eisaku Kyushu University, Faculty of Engineering, Professor, 工学部, 教授 (70148914)
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| Project Period (FY) |
1995 – 1997
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| Keywords | three bridged / binuclear complex ion / interaction between metal ions / CASSCF / MRSDCI / covalency / excitation energy |
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| Research Abstract |
Three bridged complex ion, M_2Cl_9^<3・> (M=Cr, Mo) is composed of the crystal in the form of Cs_3M_2Cl_9 and M^<3+> ion is surrounded by 6 ligands in almost O_h form and two metal ions hold 3 ligans in common. Cr^<3+> and Mo^<3+> possess three d valence elctrons. The two binuclear ions show quite different electronic spectra. In the last academic year, we obtained the lowest states lead by the same configuration of the spin multiplets of 1,3,5 and 7 states separated within 13cm^<-1> for Cr case, whereas Mo ion splits the range of 8000 cm^<-1>. The calculated singlet-triplet separation of 782cm^<-1> agrees very well with observed value of 840cm^<-1>. However we could not obtain good agreement with experiment for the higher excited states. To improve the situation, we prepare 3 states averaged CASSCF MO to obtain comparable results with the ground state and carried out MRSDCI.As the interaction between metal ions is weak in Cr system, it has been expected that the electronic spectrum is interpreted well by the data of CrCl_6^<3・>. The results support the expectation ; the excited states located at 1.5-1.7eV and 2-2.5eV are interpreted as the excitation of t_2*ein one of Cr as {(ts_2^2e)^4T_2X (t_2^3)^4A_2} and {(t_2^2e)^4T_1X (t_2^3)^4A_2}, respectively. The excited states located at 1.35 and 1.4eV are expressed as {(t_2^2e)^4T_2X (t_2^3)^4A_2} and {(t_2^2e)^4T_1X (t_2^3)^4A_2}, respectively. In Mo system, covalency is much stronger than Cr case, the interpretation just as Cr is not clearly applicable but lower states are almost described as intrat_2^3 transitions in one Mo ion.
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