- Preparation and Properties of Annelated Tropylium Salts
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The insertion of methylene into the aromatic ring of benzocyclobutene leads to a mixture of cyclobutane-fused cycloheptatrienes.Treatment of this mixture with a trityl salt affords the cyclobutane-fused tropylium salt in essentially pure form.If this same synthetic approach is applied to other annelated benzenes, bis- and tris-annelated salts can be prepared.The proton and carbon-13 NMR spectra of a series of annelated tropylium salts have been analyzed and interpreted in terms of a rehybridization theory.Small but meaningful trends have been observed in the ultraviolet absorption spectra and pKR+ values.
- Thummel, Randolph P.,Chayangkoon, Paochai
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- Synthesis and structure of tritylium salts
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Several tritylium compounds [Ph3C][A] have been isolated by salt metathesis or halide abstraction reactions starting from Ph3C-X (X = halogen) and Lewis acids in good yields (A = BF4, BCl4, AlCl4, GaCl4, PF6, AsF6, SbF6, SbCl6, CHB11H5Cl6, CHB11Cl11, CHB11H5Br6, CF3COO, CF3SO3, N3). The structures of 15 tritylium salts bearing different types of weakly coordinating anions (A-) have been determined. The structures are discussed on the basis of ion pairing versus covalent bond formation and solid-state interactions in comparison with gas-phase data.
- Hinz, Alexander,Labbow, René,Rei?, Fabian,Schulz, Axel,Sievert, Katharina,Villinger, Alexander
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p. 1641 - 1650
(2015/10/28)
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