Computational Insight into 103Rh Chemical Shift–Structure Correlations in Rhodium Bis(phosphine) Complexes
| Autor: | Manuel A. Ortuño, Michael Bühl, Ludovic Castro |
|---|---|
| Přispěvatelé: | University of St Andrews. School of Chemistry, University of St Andrews. EaSTCHEM |
| Rok vydání: | 2013 |
| Předmět: |
Noncovalent interactions
Shielding tensors Inorganic chemistry chemistry.chemical_element Density-functional theory Transition-metal-complexes Rhodium Inorganic Chemistry Organometallic complexes chemistry.chemical_compound NMR spectroscopy Diolefin complexes Olefin complexes Physical and Theoretical Chemistry BINAP Isodesmic reaction Chemical shift Organic Chemistry Nuclear magnetic resonance spectroscopy Molecular orbital methods chemistry Basis sets Physical chemistry Density functional theory Phosphine Cyclooctadiene |
| Zdroj: | Organometallics. 32:6437-6444 |
| ISSN: | 1520-6041 0276-7333 |
| DOI: | 10.1021/om400774y |
| Popis: | 103RhNMR chemical shifts have been computed at the GIAO-B3LYP level of density functional theory (DFT) for a number of [Rh(COD)(P∩P)]+ complexes [COD = 1,5-cyclooctadiene, P∩P = chelating bis(phosphine) including bis(dimethylphosphino)ethane (dmpe), bis(diphenylphosphino)ethane (dmpe), MeDUPHOS, DIOP, BINAP, and others]. Structures have been optimized using PBE0 and M06 functionals in the gas phase, in a continuum modeling the solvent, and with [PF6]− counteranion included explicitly. Observed trends in δ(103Rh) are well reproduced for pristine PBE0-optimized cations in the gas phase or for ion pairs optimized in a continuum with M06. While there is no overall trend between computed δ(103Rh) values and complex stabilities (evaluated through isodesmic ligand exchange reactions), there is a linear relationship between the 103Rh chemical shifts and the mean Rh–P bond distances. This relationship appears to be remarkably general, encompassing various chelating ring sizes and substituents at P, including remote electron-donating and -withdrawing substituents that are characterized through their Hammett constants. The combination of 103Rh NMR and DFT computations emerges as a useful tool for structure elucidation of Rh–phosphine complexes. Postprint |
| Databáze: | OpenAIRE |
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