1998 Fiscal Year Final Research Report Summary
Structure and Reactivity of Organopalladium Complexes Bearing Unusual Oxidation State of Pd
Project/Area Number |
09490022
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
広領域
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Research Institution | Osaka University |
Principal Investigator |
KUROSAWA Hideo Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (40029343)
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Co-Investigator(Kenkyū-buntansha) |
KUNIYASU Hitoshi Osaka University, Graduate School of Engineering, Assistant, 大学院・工学研究科, 助手 (00252594)
OGOSHI Sensuke Osaka University, Graduate School of Engineering, Assistant, 大学院・工学研究科, 助手 (30252589)
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Project Period (FY) |
1997 – 1998
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Keywords | Pd(IV) Complex / Pd(I) Complex / Organopalladium |
Research Abstract |
The aim of this project is i) to synthesize a number of organopalladium complexes having a formal oxidation state of Pd(I) or Pd(IV), ii) to elucidate their molecular and electronic structures, and iii) to explore some reactivities characteristic of such structures. The principal findings obtained follow. 1) Transformations proceeding through Pd(IV) complexes PI-Allyl complex containing the chloromethyl group at 2-position of the allyl framework, [Pd(CH_2C(CH_2Cl)CH_2)(C_5H_5)] afforded C-C bond formation product, [Pd(CH_2C(CH_2G_5H_5)CH_2)Cl] via a Pd(IV)-metallacycle [Pd(CH_2C(=CH_2)CH_2)(C_5H_5)] ^+. Other than the C_5H_5 ligand, the SPh group of [Pd(CH_2C(CH_2CL)CH_2)SPh] also enabled an analogous transformation via the Pd(IV) intermediate, giving rise to [Pd(CH_2C(CH_2SPh)CH_2)CI]. 2) Synthesis and structure of Pd(I) complexes A general method of synthesizing Pd(I)-Pd(I) dinuclear complexes has been developed by making use of coupling between Pd(0) and Pd(II) species with butadiene playing a template role. Thus, employing some ligands on Pd(II) (Cl, Br, I) and diene ligands led to selective synthesis of anionic, [Pd_2X_3(diene)], neutral, [Pd_2X_2(PPh_3)(diene)], and cationic, [Pd_2X(PPh_3)_2(diene)] ^+ dinuclear complexes. X-Ray structure determinations confirmed the s-trans bridging diene ligand. The diene ligands so coordinating included anionic dienolate. The structure determination also revealed unusually long Pd-Pd distance (3.19 A) in [Pd_2(PPh_3) _2(diene) _2] ^<2+>, a value much longer than the previously reported Pd-Pd length (-2.83 A). MO calculations indicated that such elongated Pd-Pd length is attributed to back donation of electron densities from the Pd-Pd bond to LUMO of the diene. The unusual dicationic dipalladium complex reacted with acetonitrile or acetylene to result. in liberation of two or one diene molecule, respectively.
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Research Products
(10 results)