Synthesis and characterization of luminescent zinc(II) and cadmium(II) complexes with N,S-chelating schiff base ligands
Synthesis and characterization of luminescent zinc(II) and cadmium(II) complexes with N,S-chelating schiff base ligands
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DOI：
10.1021/ic7020758
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发表时间：
2008-04-21
影响因子：
4.6
通讯作者：
Konno, Takumi
中科院分区：
文献类型：
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作者：
Kawamoto, Tatsuya;Nishiwaki, Masato;Konno, Takumi
乙酸锌(II)与各种2-取代苯并噻唑啉的反应提供了具有N2S2供体组的四面体单核配合物，[Zn(R-Ph-C(H).=N-C6H4-S)2]。根据吸收光谱的特征，所得锌(II)配合物可分为三类：第 1 组（R = 2,4,6-triMe (1)、2,6-diCl (2)）在 250-300 nm 处显示强带，在 400-450 nm 处显示弱带，第 2 组（R = 4-Cl (3)、H (4)、4-Et (5)、4-OMe (6)）在 250-300 nm 处显示两个强带，在 400-450 nm 处显示弱带。 400-450 nm，第 3 组（R = 4-NMe2 (7)、4-NEt2 (8)) 在 250-300 nm 处显示一条强带，在 350-450 nm 处显示两个非常强的带。第2族和第3族配合物在紫外光照射下表现出强发射性，而第1族配合物在室温下不发射。然而，所有锌(II)配合物在CH2Cl2/甲苯玻璃中在77 K下都发光，并且发现它们的发射峰能量与每个配合物中苯环对位取代基的哈米特常数相关。乙酸镉(II)与2-取代苯并噻唑啉也进行了类似的反应，合成了相应的镉(II)配合物。虽然在苯环邻位具有大取代基的 [Cd(R-Ph-C(H)=N-C6H4-S)(2)] (R = 2,4,6-triMe (9)) 具有四面体单核结构，但其他镉 (II) 配合物 [Cd-2(R-Ph-C(H)=N-C6H4-S)(4)] (R = 4-Et (10), 4-OMe (11), 4-NMe2 (12)) 具有 S 桥双核结构。这些镉（II）络合物被认为在溶液中具有单核结构，显示出与相应的锌（II）络合物相似的光物理性质。
The reactions of zinc(II) acetate with a variety of 2-substituted benzothiazolines afforded tetrahedral mononuclear complexes with a N2S2 donor set, [Zn(R-Ph-C(H).=N-C6H4-S)2]. The obtained zinc(II) complexes can be divided into three groups based on the characteristics of the absorption spectra; Group 1 (R = 2,4,6-triMe (1), 2,6-diCl (2)) showing an intense band at 250-300 nm and a weak band at 400-450 nm, Group 2 (R = 4-Cl (3), H (4), 4-Et (5), 4-OMe (6)) showing two intense bands at 250-300 nm and a weak band at 400-450 nm, and Group 3 (R = 4-NMe2 (7), 4-NEt2 (8)) showing an intense band at 250-300 nm and two very intense bands at 350-450 rim. The Group 2 and Group 3 complexes exhibited a strong emission on irradiating with ultraviolet light while the Group 1 complexes were not emissive at room temperature. However, all the zinc(II) complexes were luminescent in CH2Cl2/toluene glass at 77 K, and their emission peak energies were found to correlate with the Hammett constant of the substituent at para position of a pendent phenyl ring in each complex. Similar reactions of cadmium(II) acetate with 2-substituted benzothiazolines were also carried out to synthesize corresponding cadmium(II) complexes. While [Cd(R-Ph-C(H)=N-C6H4-S)(2)] (R = 2,4,6-triMe (9)) with bulky substituents at ortho positions of a pendent phenyl ring had a tetrahedral mononuclear structure, other cadmium(II) complexes [Cd-2(R-Ph-C(H)=N-C6H4-S)(4)] (R = 4-Et (10), 4-OMe (11), 4-NMe2 (12)) possessed S-bridged dinuclear structures. These cadmium(II) complexes, which are assumed to have a mononuclear structure in solution, showed photophysical properties similar to those of the corresponding zinc(II) complexes..