- Heterometallic cubanes: Syntheses, structures, and magnetic properties of lanthanide(III)-nickel(II) architectures
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Reactions of lanthanide(III) perchlorate (Ln = Dy, Tb, and Gd), nickel(II) acetate, and ditopic ligand 2-(benzothiazol-2-ylhydrazonomethyl)-6-methoxyphenol (H2L) in a mixture of methanol and acetone in the presence of NaOH resulted in the successful assembly of novel Ln2Ni2 heterometallic clusters representing a new heterometallic 3d-4f motif. Single-crystal X-ray diffraction reveals that all compounds are isostructural, with the central core composed of distorted [Ln2Ni2O 4] cubanes of the general formula [Ln2Ni 2(μ3-OH)2(OH)(OAc)4(HL) 2(MeOH)3](ClO4)·3MeOH [Ln = Dy (1), Tb (2), and Gd (3)]. The magnetic properties of all compounds have been investigated. Magnetic analysis on compound 3 indicates ferromagnetic Gd...Ni exchange interactions competing with antiferromagnetic Ni...Ni interactions. Compound 1 displays slow relaxation of magnetization, which is largely attributed to the presence of the anisotropic DyIII ions, and thus represents a new discrete [Dy2Ni2] heterometallic cubane exhibiting probable single-molecule magnetic behavior.
- Gao, Yajie,Zhao, Lang,Xu, Xuebin,Xu, Gong-Feng,Guo, Yun-Nan,Tang, Jinkui,Liu, Zhiliang
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- Syntheses, crystal structures, and magnetic properties of μ-O/μ-Cl bridged dinuclear manganese(II) and copper(II) complexes with schiff base ligand HL [HL = 2-(benzothiazol-2-yl-hydrazonomethyl)-6-methoxyphenol]
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A novel versatile multidentate ligand 2-(benzothiazol-2-yl-hydrazonomethyl) -6-methoxyphenol (HL), was obtained from a condensation reaction between 2-hydrazino benzothiazole and o-vanillin. The reactions of HL with CuCl 2·2H2O/Mn(ClO4)2· 6H2O generated two novel dinuclear compounds Cu2L(μ-Cl) Cl2(CH3OH)2 (1) and Mn2L 3(ClO4)(CH3CH2OH)3 (2). The crystal structures of 1 and 2 were determined by X-ray diffraction studies. The two copper atoms in complex 1 are connected by a L- anion and a single chloro bridge with a Cu···Cu separation of 3.2729(4) A. In complex 2, the two manganese atoms are held together by two L - anion bridges and the Mn···Mn separation amounts to 3.3433(7) A. As expected, variable-temperature magnetic susceptibility measurements of complex 1 showed strong antiferromagnetic intramolecular coupling between the copper(II) atoms with J =-102.2 cm -1, and evidenced for complex 2 weak antiferromagnetic coupling with J =-1.68 cm-1. Copyright
- Gao, Yajie,Ji, Yufei,Ding, Shuai,Liu, Zhiliang,Tang, Jinkui
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- Synthesis and structural characterization of facile ruthenium(II) hydrazone complexes: Efficient catalysts in α-alkylation of ketones with primary alcohols via hydrogen auto transfer
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As a immersion for development of new complexes, new Ru(II) complexes (1–3) supported by benzothiazole hydrazine Schiff bases of the type [Ru(SAL-HBT)(CO)(AsPh3)2], [Ru(VAN-HBT)(CO)(AsPh3)2] and [Ru(NAP-HBT)(CO)Cl(AsPh3)2] [SAL-HBT = (salicyl((2-(benzothiazol-2yl)hydrazono)methylphenol)), VAN-HBT = 2-((2-(benzothiazol-2-yl)hydrazono)methyl)-6 methoxyphenol) and NAP-HBT = naphtyl-2-((2-(benzothiazol-2-yl)hydrazono)methyl phenol)] were synthesized. Their identities have been established by satisfactory elemental analyses, various spectroscopic techniques (IR, (1H, 13C) NMR) and also mass spectrometry. The ruthenium(II) ion exhibits a hexa coordination with distorted octahedral geometry. In complexes 1 and 2, the ligand coordinated as dianionic tridentate fashion by forming N^N donor five member and N^O donor six member chelate rings. However, in complex 3, the ligand coordinated as monoanionic bidentate fashion by forming N^N donor five-membered ring. The new ruthenium(II) carbonyl complexes were successfully applied as catalysts in α -alkylation of aliphatic and aromatic ketones with alcohols via borrowing hydrogen strategy. Various parameters such as base, solvent, temperature, time and catalyst loading on the catalytic activity were analyzed. From the results, the catalyst 1 was found to be the best catalyst for α-alkylation reaction to obtain excellent yield. The catalytic system has a broad substrate scope, which allows the synthesis of α-alkylated ketones in mild reaction conditions with low catalyst loading under air atmosphere.
- Kalaiarasi, Chinnasamy,Murugan, Kaliyappan,Vijayan, Paranthaman,Vijayapritha, Subbarayan,Viswanathamurthi, Periasamy
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- Convenient and efficient Suzuki-Miyaura cross-coupling reactions catalyzed by palladium complexes containing N,N,O-tridentate ligands
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N,N,O-Tridentate ligands 1-9 were prepared from the condensation of amines with nine aromatic aldehydes or ketones. These ligands are thermally stable and neither air- nor moisture-sensitive. Combination of either 2-methoxy-6-[(pyridine-2-ylmethylimino)-m
- Patil, Siddappa A.,Weng, Chia-Ming,Huang, Po-Cheng,Hong, Fung-E.
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experimental part
p. 2889 - 2897
(2009/05/30)
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