Synthesis and Coordination Chemistry of a New N4-Polydentate Class of Pyridyl-Functionalized Scorpionate Ligands: Complexes of FeII, ZnII, NiII, VIV
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- 作者：Riccardo Wanke ; M. Ftima C. Guedes da Silva ; Stefano Lancianesi ; Telma F. S. Silva ; Lusa M. D. R. S. Martins ; Claudio Pettinari ; Armando J. L. Pombeiro
- 刊名：Inorganic Chemistry
- 出版年：2010
- 出版时间：September 6, 2010
- 年：2010
- 卷：49
- 期：17
- 页码：7941-7952
- 全文大小：1095K
- 年卷期：v.49,no.17(September 6, 2010)
- ISSN：1520-510X
文摘
The new potentially N4-multidentate pyridyl-functionalized scorpionates 4-((tris-2,2,2-(pyrazol-1-yl)ethoxy)methyl)pyridine (TpmPy, (1)) and 4-((tris-2,2,2-(3-phenylpyrazol-1-yl)ethoxy)methyl)pyridine (TpmPyPh, (2)) have been synthesized and their coordination behavior toward FeII, NiII, ZnII, CuII, PdII, and VIII centers has been studied. Reaction of (1) with Fe(BF4)2·6H2O yields [Fe(TpmPy)2](BF4)2 (3), that, in the solid state, shows the sandwich structure with trihapto ligand coordination via the pyrazolyl arms, and is completely low spin (LS) until 400 K. Reactions of 2 equiv of (1) or (2) with ZnII or NiII chlorides give the corresponding metal complexes with general formula [MCl2(TpmPy*)2] (M = Zn, Ni; TpmPy* = TpmPy, TpmPyPh) (4−7) where the ligand is able to coordinate through either the pyrazolyl rings (in case of [Ni(TpmPy)2]Cl2 (5)) or the pyridyl-side (for [ZnCl2(TpmPy)2] (4), [ZnCl2(TpmPyPh)2] (6) and [NiCl2(TpmPyPh)2] (7)). The reaction of (1) with VCl3 gives [VOCl2(TpmPy)] (8) that shows the N3-pyrazolyl coordination-mode. Moreover, (1) and (2) react with cis-[PdCl2(CH3CN)2] to give the disubstituted complexes [PdCl2(TpmPy)2] (9) and [PdCl2(TpmPyPh)2] (10), respectively, bearing the scorpionate coordinated via the pyridyl group. Compounds (9) and (10) react with Fe(BF4)2 to give the heterobimetallic Pd/Fe systems [PdCl2(μ-TpmPy)2Fe](BF4)2 (11) and [PdCl2(μ-TpmPyPh)2Fe2(H2O)6](BF4)4 (13), respectively. Compound (11) can also be formed from reaction of (3) with cis-[PdCl2(CH3CN)2], while reaction of (3) with Cu(NO3)2·2.5H2O generates [Fe(μ-TpmPy)2Cu(NO3)2](BF4)2 (12), confirming the multidentate ability of the new chelating ligands. The X-ray diffraction analyses of compounds (1), (3), (4), (5), and (9) are also reported.