Formation, Structural Characterization, and Calculated NMR Chemical Shifts of Selenium‐Nitrogen Compounds from SeCl<sub>4</sub> and ArNHLi (Ar = supermesityl, mesityl)
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Bibliographic record
Abstract
Abstract Supermesityl selenium diimide [Se{N(C 6 H 2 t Bu 3 ‐2, 4, 6)} 2 ; Se{N(mes*)} 2 ] can be prepared in a good yield from the reaction of SeCl 4 and (mes*)NHLi. The molecule adopts an unprecedented anti, anti ‐conformation, as deduced by DFT calculations at PBE0/TZVP level of theory and supported by 77 Se NMR spectroscopy and a crystal structure determination. An analogous reaction involving (C 6 H 2 Me 3 ‐2, 4, 6)NHLi [(mes)NHLi] unexpectedly lead to the reduction of selenium and afforded the selenium diamide Se{NH(mes)} 2 that was characterized by X‐ray crystallography and 77 Se NMR spectroscopy. The Se‐N bonds of 1.847(3) and 1.852(3) Å show normal single bond lengths. The <NSeN bond angle of 109.9(1)° also indicates a tetrahedral AX 2 E 2 bonding arrangement around selenium. Two N‐H···N hydrogen bonds link the Se{NH(mes)} 2 molecule with two discrete (mes)NH 2 molecules. In the solid state selenium diamide adopts the anti ‐conformation, whereas in solution the presence of both syn ‐ and anti ‐isomers could be observed. PBE0/TZVP calculations of the shielding tensors of 28 different types of selenium‐containing molecules, for which the 77 Se chemical shifts are unambiguously known, were carried out to assist the spectral assignment of Se{N(mes*)} 2 and Se{NH(mes)} 2 .
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Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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