Syntheses, structural characterization and photophysical properties of 4-(2-pyridyl)-1,2,3-triazole rhenium(I) complexes
Syntheses, structural characterization and photophysical properties of 4-(2-pyridyl)-1,2,3-triazole rhenium(I) complexes
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DOI：
10.1039/b718538c
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发表时间：
2008-01-01
影响因子：
4
通讯作者：
Yano, Shigenobu
中科院分区：
文献类型：
--
作者：
Obata, Makoto;Kitamura, Asuka;Yano, Shigenobu
新型螯合剂，i.例如，4-通过Cu（I）催化的1，3-偶极环加成反应合成了2-吡啶基-1，2，3-三唑衍生物，并将其用于制备稀土配合物[ReCl（CO）（3）]（Bn-pyta）]、[ ReCl（CO）（3）（AcGlc-pyta）]和[ ReCl（CO）（3）（Glc- Pyta）]（Bn-pyta = 1-苄基-4-（2-吡啶基）-1，2，3-三唑，AcGlc-pyta = 2-（三氟甲基）苯基）-1，2，3-三唑（4-（2-吡啶基）-1，2，3-三唑-1-基）乙基2，3，4，6-四- O-乙酰基-β-D-吡喃葡萄糖苷，Glc-吡塔= 2-（4-（2-吡啶基）-1，2，3-三唑-1-基）乙基β-D-吡喃葡萄糖苷）。Bn-pyta和Glc-pyta的X射线晶体学表明偶氮化合物样结构，而1，2，4-三唑异构体具有吖嗪特征。[ ReCl（CO）3（Bn-pyta）]晶体属单斜晶系，空间群为P2（1）/n。Bn-pyta配体与2-吡啶基上的氮原子和1，2，3-三唑环的3-位配位，这与2，2 ' -联吡啶衍生物的配位方式非常相似。葡萄糖共轭Re（I）配合物[ ReCl（CO）（3）（AcGlc-pyta）]和[ ReCl（CO）（3）（Glc-pyta）]几乎不结晶，并通过扩展X射线吸收精细结构（EXAFS）分析进行了分析。EXAFS分析表明，1，2，3-三氮唑1位的葡萄糖共轭对4-（2-吡啶基）-1，2，3-三氮唑的配位方式没有影响。与[ReCl（CO）（3）（bpy）]（371 nm，3.35 x 10（3）M-1 cm（-1））相比，[ ReCl（CO）3（Bn-pyta）]显示出蓝移的最大吸收（333 nm，3.97 x 10（3）M-1 cm（-1））。基于含时密度泛函理论计算，这些反应被明确地归属为混合金属-配体-配体电荷转移（MLLCT）。与[ ReCl（CO）3（bpy）]相比，[ReCl（CO）（3）（Bn-pyta）]的发光光谱也显示出这种蓝移特征. [ ReCl（CO）（3）（Bn-pyta）]在2-甲基四氢呋喃中的发光寿命为8.90 μ s，比[ReCl（CO）（3）（bpy）]的发光寿命（3.17 μ s）长. [ ReCl（CO）（3）（Bn-pyta）]的蓝移电子吸收和延长的发光寿命表明，4-（2-吡啶基）-1，2，3-三唑是一种富电子双齿螯合剂.
Novel chelators, i. e., 4-(2-pyridyl)- 1,2,3- triazole derivatives, were synthesized by means of Cu( I)- catalyzed 1,3- dipolar cycloaddition and used to prepare luminescent Re( I) complexes [ReCl(CO)(3)( Bn- pyta)], [ ReCl(CO)(3)(AcGlc- pyta)] and [ ReCl(CO)(3)(Glc- pyta)] (Bn- pyta = 1- benzyl- 4-( 2- pyridyl)- 1,2,3- triazole, AcGlc- pyta = 2-( 4-( 2- pyridyl)- 1,2,3- triazol- 1- yl) ethyl 2,3,4,6- tetra- O- acetyl- beta-D- glucopyranoside, Glc- pyta = 2-( 4-( 2- pyridyl)- 1,2,3- triazol- 1- yl) ethyl beta-D- glucopyranoside). X- Ray crystallography of Bn- pyta and Glc- pyta indicated an azocompound-like structure while the 1,2,4- triazole isomer has an azine character. [ ReCl( CO) 3( Bn- pyta)] crystallized in the monoclinic system with space group P2(1)/n. Bn- pyta ligand coordinates with the nitrogen atoms of the 2- pyridyl group and the 3- position of 1,2,3- triazole ring, which is a very similar coordinating fashion to that of the 2,2' - bipyridine derivative. The glucoconjugated Re( I) complexes [ ReCl( CO)(3)( AcGlc- pyta)] and [ ReCl( CO)(3)( Glc- pyta)] hardly crystallized, and were analyzed by applying extended X- ray absorption fine structure ( EXAFS) analysis. The EXAFS analyses suggested that the glucoconjugation at the 1- position of the 1,2,3- triazole makes no influence to the coordinating fashion of 4-( 2- pyridyl)- 1,2,3- triazole. [ ReCl( CO) 3( Bn- pyta)] showed a blue-shifted maximum absorption (333 nm, 3.97 x 10(3) M-1 cm(-1)) compared with [ReCl(CO)(3)(bpy)] ( 371 nm, 3.35 x 10(3) M-1 cm(-1)). These absorptions were clearly assigned to be the mixed metal- ligand-to-ligand charge transfer (MLLCT) on the basis of time-dependent density functional theory calculation. The luminescence spectrum of [ReCl(CO)(3)( Bn- pyta)] also showed this blue- shifted feature when compared with that of [ ReCl( CO) 3( bpy)]. The luminescence lifetime of [ ReCl( CO)(3)( Bn- pyta)] was determined to be 8.90 mu s in 2-methyltetrahydrofuran at 77 K, which is longer than that of [ReCl(CO)(3)( bpy)] ( 3.17 mu s). The blue- shifted electronic absorption and elongated luminescence lifetime of [ ReCl( CO)(3)( Bn- pyta)] suggested that 4-( 2- pyridyl)- 1,2,3- triazole functions as an electron-rich bidentate chelator.