n3 and n6 Bridging cations in the N,N,N',N',N'-pentamethyldiethylenetriamine-solvated complexes of benzylpotassium and benzylrubidium: an x-ray, NMR, and MO study
| Autor: | Dominic S. Wright, Paul von Ragué Schleyer, Peter Otto, Walter Bauer, Frank Hampel, Nicolaas J. R. van Eikema Hommes, Ronald Snaith, Daniele Hoffmann, Dietmar Stalke, Ursula Pieper |
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| Jazyk: | angličtina |
| Rok vydání: | 1994 |
| Předmět: |
PMDTA
Coordination sphere 010405 organic chemistry Stereochemistry Metalation Ligand Carbon-13 General Chemistry Crystal structure 010402 general chemistry 01 natural sciences Biochemistry Toluene Medicinal chemistry Catalysis anorganische Chemie 0104 chemical sciences 3. Good health chemistry.chemical_compound Colloid and Surface Chemistry chemistry Molecule |
| Popis: | The metalation of toluene (PhCH3) with a 1: 1 mixtureof n-BuLi/MOtBu (M = K, Rb) at ambient temperature affords orange-red powders of benzylpotassium or benzylrubidium. On addition of N,N,N’,N“,N“-pentamethyldiethylenetriamine (PMDTA) the precipitates dissolve to give burgundy-red solutions, from which needles of [PhCH2K-PMDTA.O.5PhCH3(l1n) o r [PhCH2RbPMDTA], (2) areobtained. X-ray analysis reveals that 1i ncorporates half a molecule of toluene per asymmetric unit. In both 1 and 2, the 73 and 76 interaction of one M+ cation with two benzyl fragments gives rise to the formation of polymeric chains. The coordination sphere of the cations is completed by one chelating triamine ligand. MO calculations predict multihapto metal carbon interactions to become more important from Li to Cs and substantiate the solid-state results. Ab initio calculations on three different polymers suggest that the array present in the crystal structure is the most stable. The gated decoupled 13C NMR spectrum of 1 in THF-dg solution reveals a IJ(I3C,lH) coupling constant for the benzylic. peerReviewed |
| Databáze: | OpenAIRE |
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