Effect of Ligands on the Lewis Acidity of the Metal and the Binding of N-Bases to Iridium Pincer Complexes

The coordination of pyridine (Py) and benzonitrile (PhCN) to benzene based pincer hydridochlorides [(PCP)IrH(Cl)] (1), [(POCOP)IrH(Cl)] (2), [{EtO(O)C-POCOP}IrH(Cl)] (3), and [(PCN)IrH(Cl)] (4) was studied spectroscopically and computationally to deduce the ligand influence. The variable temperature NMR ( 1 H, 31 P, 15 N) and UV/Visible spectroscopic measurements revealed preferential coordination of these N-donor ligands in the apical position of 1–4 and gave the formation enthalpies for the hexacoordinate complexes, which follow the order: 1 ≈ 4 > 3 > 2. This order nicely agrees with the order of Lewis acidity obtained for these complexes in DFT calculations. The orbital and electron density distribution analysis were performed at the DFT/M06 theory level for 1–4 and a series of p-substituted PCP-based hydridochlorides. The increasing Lewis acidity of iridium [as a maximum energy, V S,max , of molecular electrostatic potential (MEP)] correlates with decreasing basicity of Cl-ligand (as MEP minimum, V S,min ) as well as with Hammett σ p parameters of p-substituents. Importantly, these properties are conserved upon conversion into the corresponding dihydrides, as shown on the example of 1 and 4. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Авторы
Osipova E.S.1 , Gulyaeva E.S.1 , Filippov O.A. 1 , Safronov S.V.1 , Pavlov A.A.1 , Polukeev A.V.1 , Kirkina V.A.1 , Titova E.M. 1, 2 , Shubina E.S. 1, 2 , Belkova N.V.1
Издательство
Wiley-VCH Verlag
Номер выпуска
10
Язык
Английский
Страницы
1389-1397
Статус
Опубликовано
Том
2019
Год
2019
Организации
  • 1 A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str. 28, Moscow, 119991, Russian Federation
  • 2 Inorganic Chemistry Department, Peoples' Friendship University of Russia, Miklukho-Maklaya str. 6, Moscow, 117198, Russian Federation
Ключевые слова
Catalytic efficiency; Density functional calculations; Iridium; Lewis acids; Lewis bases; Pincer complexes
Дата создания
19.07.2019
Дата изменения
19.07.2019
Постоянная ссылка
https://repository.rudn.ru/ru/records/article/record/38502/
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