Diastereomerization Dynamics of a Bistridentate Ru-II Complex

作者：Jarenmark Martin; Carlstrom Goran; Fredin Lisa A; Wallenstein Joachim Hedberg; Doverbratt Isa; Abrahamsson Maria; Persson Petter^*

来源：Inorganic Chemistry, 2016, 55(6): 3015-3022.

DOI：10.1021/acs.inorgchem.5b02893

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 similar to 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.

• 出版日期2016-3-21