Syntheses, characterization, density functional theory calculations, and activity of tridentate SNS zinc pincer complexes based on bis-imidazole or bis-triazole precursors
| Autor: | Raed Al-Abbasee, Elizabeth E. Butrick, Daniel J. Kwiecien, Lauren C. Keilich, John R. Miecznikowski, Amanda P. DiMarzio, Nathan F. Kloczko, Erin Powers, Wayne Lo, Matthew A. Lynn, George P. Lisi, Swapan S. Jain, Kathleen M. Foley, Brianne E. O’Loughlin |
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| Rok vydání: | 2012 |
| Předmět: |
animal structures
biology Ligand Inorganic chemistry chemistry.chemical_element Active site Zinc Pincer movement Inorganic Chemistry Bond length chemistry.chemical_compound Molecular geometry chemistry Polymer chemistry Materials Chemistry biology.protein Imidazole Physical and Theoretical Chemistry Pincer ligand |
| Zdroj: | Inorganica Chimica Acta. 387:25-36 |
| ISSN: | 0020-1693 |
| DOI: | 10.1016/j.ica.2011.12.047 |
| Popis: | A series of tridentate pincer ligands, each possessing two sulfur- and one nitrogen-donor functionalities (SNS), based on bis-imidazole or bis-triazole salts were metallated with ZnCl 2 to give new tridentate SNS pincer zinc(II) complexes [(SNS)ZnCl] + . The zinc complexes serve as models for the zinc active site in liver alcohol dehydrogenase (LADH) and were characterized with single crystal X-ray diffraction, 1 H, 13 C, and HSQC NMR spectroscopies, electrospray mass spectrometry, and elemental analysis. The zinc complexes feature SNS donor atoms and pseudotetrahedral geometry about the zinc center, as is seen for liver alcohol dehydrogenase. The bond lengths and bond angles of the zinc complexes correlate well to those in horse LADH. The SNS ligand precursors were characterized with 1 H, 13 C, and HSQC NMR spectroscopies, elemental analysis, and cyclic voltammetry, and were found to be redox active. Gaussian calculations were performed and agree with the experimentally observed oxidation potentials for the pincer ligand precursors. The zinc complexes were screened for the reduction of electron-poor aldehydes in the presence of a hydrogen donor, 1-benzyl-1,4-dihydronicotinamide (BNAH), and it was determined that they enhance the reduction of electron-poor aldehydes. The SNS zinc pincer complexes with bis-triazole ligand precursors exhibit higher activity for the reduction of 4-nitrobenzaldehyde than do SNS zinc pincer complexes with bis-imidazole ligand precursors. Quantitative stoichiometric conversion was seen for the reduction of pyridine-2-carboxaldehyde via SNS zinc pincer complexes with either bis-imidazole or bis-triazole ligand precursors. |
| Databáze: | OpenAIRE |
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