Diastereomerization Dynamics of a Bistridentate RuII Complex

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• 作者：Martin Jarenmark ; Göran Carlström ; Lisa A. Fredin ; Joachim Hedberg Wallenstein ; Isa Doverbratt ; Maria Abrahamsson ; Petter Persson
• 刊名：Inorganic Chemistry
• 出版年：2016
• 出版时间：March 21, 2016
• 年：2016
• 卷：55
• 期：6
• 页码：3015-3022
• 全文大小：457K
• ISSN：1520-510X

文摘

The unsymmetrical nature of a new tridentate ligand bis(quinolinyl)-1,3-pyrazole (DQPz) is exploited in a bistridentate Ru(II) complex [Ru(DQPz)₂]²⁺ to elucidate an unexpected dynamic diastereomerism. Structural characterization based on a combination of nuclear magnetic resonance spectroscopy and density functional theory calculations reveals the first quantifiable diastereomerization dynamics for Ru complexes with fully conjugated tridentate heteroaromatic ligands. A mechanism that involves a large-scale twisting motion of the ligands is proposed to explain the dynamic interconversion between the observed diastereomers, and the analysis of both experiments and calculations reveals a potential energy landscape with a transition barrier for the diastereomerization of ∼70 kJ mol^–1. The structural flexibility demonstrated around the central transition metal ion has implications for integration of complexes into catalytic and photochemical applications.