Monomeric and Trimeric Manganese(III) Complexes of 2-Hydroxy-5,10,15,20-tetraphenylporphyrin. Synthesis and Characterization.
Monomeric and Trimeric Manganese(III) Complexes of 2-Hydroxy-5,10,15,20-tetraphenylporphyrin. Synthesis and Characterization.
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2-羟基-5,10,15,20-四苯基卟啉的单体和三聚锰(III)络合物。
DOI：
10.1021/ic951663y
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发表时间：
1996
影响因子：
4.6
通讯作者：
L. Latos‐Grażyński
中科院分区：
文献类型：
--
作者：
J. Wojaczyński;L. Latos‐Grażyński
研究了单体五配位（2-BzO-TPP）Mn（III）Cl配合物的水解反应。(1)提出了形成环状三聚配合物[（2-O-TPP）Mn（III）]（3）的证据。（1）H NMR光谱证据表明三聚锰（III）配合物具有头-尾环状三聚体结构，其中吡咯烷氧基形成从一个大环到相邻大环PMn-O-PMn-O-PMn-O中的锰（III）离子的桥。三个锰（III）卟啉亚基是不等价的。测定了3-H吡咯共振的特征高场位移（在291 K下为-111.5 ppm），并将其视为高自旋d（4）锰（III）-吡咯醇盐配位的诊断特征。3-H共振的强高场位移是由2-O原子的填充轨道的电子密度对外部锰离子的半占据d（z）（）2轨道的贡献引起的。其他吡咯共振在典型的-5至-40 ppm区域产生复合多重峰。本文报道了一系列2-取代锰（Ⅲ）5，10，15，20-四苯基卟啉配合物（2-X-TPP）Mn（Ⅲ）Cl的~（1）H NMR谱。指定的7个吡咯共振的模式反映了由2-取代施加的不对称性，并已被用作（1）H NMR光谱探针来绘制自旋密度分布。电子效应强烈地局限于β-取代的吡咯。随着β-取代基的给电子性质的增加，3-H共振的高场位移以（2-NO（2）-TPP）Mn（III）Cl <（2-BzO-TPP）Mn（III）Cl <（2-OCH（3）-TPP）Mn（III）Cl <（2-OH-TPP）Mn（III）Cl <（2-NH（2）-TPP）Mn（III）Cl < [（2-O-TPP）Mn（III）（OH）]（-）的顺序增加。
The hydrolysis of the monomeric five-coordinate (2-BzO-TPP)Mn(III)Cl complex has been investigated.(1) Evidence for the formation of the cyclic trimeric complex [(2-O-TPP)Mn(III)](3) is presented. The (1)H NMR spectroscopic evidence indicates that the trimeric manganese(III) complex has a head-to-tail cyclic trimeric structure with the pyrrolic alkoxide groups forming bridges from one macrocycle to the manganese(III) ion in the adjacent macrocycle PMn-O-PMn-O-PMn-O. The three manganese(III) porphyrin subunits are not equivalent. The characteristic upfield shift of the 3-H pyrrole resonance (-111.5 ppm at 291 K) was determined and considered as the diagnostic feature for the high-spin d(4) manganese(III)-pyrrole alkoxide coordination. The strong upfield shift of the 3-H resonance has been accounted for by the donation of the electron density from the filled orbital of the 2-O atom on the half-occupied d(z)()()2 orbital of the external manganese(III) ion. The other pyrrole resonances produce the complex multiplet at the typical -5 to -40 ppm region. The (1)H NMR spectra of the series of monomeric 2-substituted manganese(III) 5,10,15,20-tetraphenylporphyrin complexes (2-X-TPP)Mn(III)Cl have been obtained and analyzed. The pattern of the assigned seven pyrrole resonances reflects the asymmetry imposed by 2-substitution and has been used as a (1)H NMR spectroscopic probe to map the spin density distribution. The electronic effect is strongly localized at the beta-substituted pyrrole. The upfield shift of the 3-H resonance increases in the order (2-NO(2)-TPP)Mn(III)Cl < (2-BzO-TPP)Mn(III)Cl < (2-OCH(3)-TPP)Mn(III)Cl < (2-OH-TPP)Mn(III)Cl < (2-NH(2)-TPP)Mn(III)Cl < [(2-O-TPP)Mn(III)(OH)](-) following the increasing electron-donating properties of the beta-substituent.