Interests in new heterodinuclear transition-metal/main-group-metal complexes : DFT study of electronic structure and mechanism of fluoridesensing function
Interests in new heterodinuclear transition-metal/main-group-metal complexes : DFT study of electronic structure and mechanism of fluoridesensing function
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对新型异双核过渡金属/主族金属配合物的兴趣：电子结构和氟化物传感功能机制的DFT研究
DOI：
10.1039/c3dt50597a
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Shinichi Yamabe and Shigeyoshi Sakaki
中科院分区：
文献类型：
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作者：
Wei Guan;Shinichi Yamabe and Shigeyoshi Sakaki
本文对一系列异双核配合物[（o-（Ph_2P）C_6H_4）_3M_1M_2Cl]~+（M_1 = As，Sb，Bi; M_2 = Pd，Pt）进行了系统的密度泛函理论计算，研究了其对氟离子的比色传感机理。氟阴离子与M1中心结合，以提供具有大稳定能的高价M1物种。例如，氟化物加合物形成的稳定化能对于3（M1 = Sb; M2 = Pd）为−15.5 kcal mol−1，对于6（M1 = Sb; M2 = Pt）为−16.2 kcal mol−1，其中负值表示稳定化。有趣的是，第三膦与M2中心的别构配位是由氟化物加合物的形成引起的。对于氯离子、溴离子和硫氰酸根阴离子，结合能为正（约4.5 kcal mol−1），并且不会发生变构配位。在氟加合物形成引起的吸收光谱变化中，变构配位起着至关重要的作用。例如，氟化物加合物的形成猝灭了3在400 nm附近的吸收带，并在较长波长475和451 nm处新显示出两个吸收峰。这两个峰归属于配体场跃迁（dxy → dz 2和dx 2 −y2 → dz 2），包括金属到配体的电荷转移特征。讨论了只有氟加合物才能发生变构配位，并在长波区引起这两种吸收的原因。此外，Bi-Pd组合也被推荐用于氟化物敏感材料，而Sb-Pt组合被推荐用于氰化物敏感材料。
Systematic DFT calculations were carried out on a series of heterodinuclear complexes [(o-(Ph2P)C6H4)3M1M2Cl]+ (M1 = As, Sb, or Bi; M2 = Pd or Pt) to investigate the mechanism of colorimetric sensing function for the fluoride anion. The fluoride anion binds with the M1 center to afford a hypervalent M1 species with large stabilization energy. For instance, the stabilization energy by the fluoride adduct formation is −15.5 kcal mol−1 for 3 (M1 = Sb; M2 = Pd) and −16.2 kcal mol−1 for 6 (M1 = Sb; M2 = Pt), where a negative value represents stabilization. Interestingly, the allosteric coordination of the third phosphine with the M2 center is induced by the fluoride adduct formation. For chloride, bromide, and thiocyanide anions, the binding energies are positive (∼4.5 kcal mol−1), and the allosteric coordination does not occur. The allosteric coordination plays a crucial role in the absorption spectrum change induced by the fluoride adduct formation. For instance, the fluoride adduct formation quenches the absorption band of 3 around 400 nm and newly exhibits two absorption peaks at longer wavelength, 475 and 451 nm. These two peaks are assigned to ligand-field transitions (dxy → dz2 and dx2−y2 → dz2) including metal-to-ligand charge transfer character. We discussed the reasons why the allosteric coordination can occur only in the fluoride adduct and induces these two absorptions in the longer wavelength region. In addition, the Bi–Pd combination is also recommended for a fluoride sensing material, while the Sb–Pt combination is recommended for cyanide sensing.