Trifluormethylsubstituierte plumbane. Synthese, eigenschaften und NMR-Spektren der verbindungen (CF3)nPbR4-n (n = 1–3) und (C
| Autor: | R. Eujen, A. Patorra |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
chemistry.chemical_classification
Trifluoromethyl Stereochemistry Organic Chemistry Halide Nuclear magnetic resonance spectroscopy Biochemistry Medicinal chemistry Inorganic Chemistry chemistry.chemical_compound chemistry Reagent Halogen Materials Chemistry Mass spectrum Physical and Theoretical Chemistry Solvent effects Alkyl |
| Zdroj: | Journal of Organometallic Chemistry. 438:57-75 |
| ISSN: | 0022-328X |
| DOI: | 10.1016/0022-328x(92)88006-5 |
| Popis: | Trifluoromethylated derivatives of lead, (CF3)nPbR4-n (n = 1–3; R = CH3, C2H5), have been prepared by a stepwise halide/CF3 exchange from (CF3)nPbR3-nX (n=O–2) and donor-stabilized (CF3)2Cd. Upon treatment of CF3PbR3 and (CF3)2PbR2 with halides under mild conditions, selective cleavage of the PbC(H) bond and formation of the corresponding alkyl(trifluoromethyl)haloplumbanes were achieved, whereas with (CF3)3PbMe only (CF3)2PbMeX was obtained. The direct exchange of alkyl and trifluoromethyl groups was observed for the systems PbR4/(CF3)n E (E = Hg, Ge, Sn), (CF3)4Sn being the most efficient CF3 transfer reagent. All compounds were characterized by vibrational, mass and multinuctear NMR spectroscopy. The NMR coupling constants nJ(207PbE) (E = 19F, 1H, 13C), which vary strongly with solvents and substituents, have been determined along with their absolute signs. Linear correlations were found between 1J(207PbCF3) and 2J(207PbF) or 2J(207PbF) and 2J(119SnF) of homologous trifluoromethylated stannanes, respectively. |
| Databáze: | OpenAIRE |
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