Square‐Planar Ruthenium(II) Complexes: Control of Spin State by Pincer Ligand Functionalization. Issue 2 (30th October 2014)

• Record Type: Journal Article
• Authors: Askevold, Bjorn; Khusniyarov, Marat M.; Kroener, Wolfgang; Gieb, Klaus; Müller, Paul; Herdtweck, Eberhardt; Heinemann, Frank W.; Diefenbach, Martin; Holthausen, Max C.; Vieru, Veacheslav; Chibotaru, Liviu F.; Schneider, Sven
• Is Part Of: Chemistry. Volume 21:Issue 2(2015)
• Page Start: 579
• Page End: 589
• Publication Date: 2014-10-30
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201404282
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Functionalization of the PNP pincer ligand backbone allows for a comparison of the dialkyl amido, vinyl alkyl amido, and divinyl amido ruthenium(II) pincer complex series [RuCl{N(CH₂CH₂P<italic>t</italic>Bu₂)₂}], [RuCl{N(CHCHP<italic>t</italic>Bu₂)(CH₂CH₂P<italic>t</italic>Bu₂)}], and [RuCl{N(CHCHP<italic>t</italic>Bu₂)₂}], in which the ruthenium(II) ions are in the extremely rare square‐planar coordination geometry. Whereas the dialkylamido complex adopts an electronic singlet (<italic>S</italic>=0) ground state and energetically low‐lying triplet (<italic>S</italic>=1) state, the vinyl alkyl amido and the divinyl amido complexes exhibit unusual triplet (<italic>S</italic>=1) ground states as confirmed by experimental and computational examination. However, essentially non‐magnetic ground states arise for the two intermediate‐spin complexes owing to unusually large zero‐field splitting (<italic>D</italic>&gt;+200 cm⁻¹). The change in ground state electronic configuration is attributed to tailored pincer ligand‐to‐metal π‐donation within the PNP ligand series.</p> </abstract>