Cr(i )Cl as well as Cr+are stabilised between two cyclic alkyl amino carbenes
| Autor: | Jonathan H. Christian, Naresh S. Dalal, Pattiyil Parameswaran, Franc Meyer, Regine Herbst-Irmer, Serhiy Demeshko, Susmita De, A. Claudia Stückl, Wolfgang Kaim, Jasleen K. Bindra, Kartik Chandra Mondal, Vallyanga Chalil Rojisha, Dietmar Stalke, Prinson P. Samuel, Roman Neufeld, Herbert W. Roesky |
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| Rok vydání: | 2015 |
| Předmět: |
Trigonal planar molecular geometry
chemistry.chemical_classification Cationic polymerization General Chemistry Photochemistry cyclic alkyl amino carbenes law.invention Metal Crystallography chemistry.chemical_compound chemistry law visual_art Yield (chemistry) visual_art.visual_art_medium Electron paramagnetic resonance Ground state Carbene Alkyl |
| Zdroj: | Chemical Science. 6:3148-3153 |
| ISSN: | 2041-6539 2041-6520 |
| DOI: | 10.1039/c5sc00646e |
| Popis: | Cr(I)Cl is a very unstable species. The present work describes the stabilisation of Cr(I)Cl in the low coordinate environment of cyclic alkyl(amino) carbene ligands and its synthetic application to yield an unprecedented cationic complex with a two coordinate Cr(I). One electron reduction of (cAAC)2CrCl2 (1) with equivalent amount of KC8 results in the formation of (cAAC)2CrCl (2), with a distorted trigonal planar configuration at the metal centre. SQUID, EPR and theoretical studies reveal a Cr(I) centre with S = 5/2 spin ground state for 2. It represents the first example of a mononuclear Cr complex showing slow relaxation of magnetisation under an applied magnetic field. The chlorine atom in 2 is expected to be prone to further reactions with appropriate reagents. This qualifies 2 as a promising precursor for the preparation of various interesting complexes with Cr(I) in a low coordinate environment. The first example of this metathesis reaction is observed when 2 is treated with Na[B(C6H3(CF3)2)4] resulting in [(cAAC)2Cr]+[B(C6H3(CF3)2)4]−, a linear cationic complex with two coordinate Cr(I) and an S = 5/2 spin ground state. peerReviewed |
| Databáze: | OpenAIRE |
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