Messung der Donorstärke substituierter 1‐Naphthole

Abstract

Measurement of the Donor Strength of Substituted 1‐Naphthols The oxidation potential of various substituted naphthols is available by cyclovoltammetry. The donor strength of substituents on the oxidation potential may be explained on the base of substituent increments. When correlating the oxidation potential with the transition energy of charge transfer complexes with TCNE, 1‐naphthols with 8‐alkoxy substituents and naphthols without oxygen in position 8 are giving different correlation curves. The experimental values correlate well with semiempirically calculated HOMO energies. Our measurements allow to predict the oxidation potentials of hitherto unknown substituted 1‐naphthols with high probality. Thus, it may be possible to synthesize 1‐naphthols with a defined oxidation potential.

Reactions of 1-Naphthols with .PI.-Acceptor p-Benzoquinones: Oxidative Aryl Coupling vs. Non-Oxidative Electrophilic Arylation

“…On the other hand, since it is also well-known that p-benzoquinones such as 1,4-benzoquinone (BQ), p-chloranil (CA), and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as p-electron acceptors 25,26) often form highly colored EDA (or charge-transfer) complexes with various donors, including arenes, charge-transfer (CT) interactions 27) might play a role in these electron-transfer reactions. In addition, many studies on thermal and photochemical reactions via CT complexes have been reported.…”

Charge-Transfer Interaction of Aromatic Thiols with 2,3-Dichloro-5,6-dicyano-p-benzoquinone: Spectral and Quantum Mechanical Studies

“…Because the sulfur atom of the thiol group has two lone pairs of electrons, it is expected to behave as a donor molecule. , On the other hand, the π-orbitals of the benzene nucleus in thiol derivatives also have a donor property. Quinone derivatives are well-known for their π-acceptor property because they have an empty π* orbital (LUMO). , Therefore studies on the electron transfer between them are important for the fabrication of conducting materials useful in future molecular electronic applications . Although CT complexes of phenolic and aniline derivatives with different acceptors have been studied extensively, only a few reports have been published on CT complexes of thiol derivatives with different acceptors. − In the present study, we are focusing on the CT interaction of aromatic thiols such as thiophenol (TP), benzene-1,4-dithiol (BDT), p -aminothiophenol (ATP), p -hydroxythiophenol (HTP), and p -toluenethiol (TTP) ( 1 − 5 ) as donors with acceptor 2,3-dichloro-5,6-dicyano- p -benzoquinone (DDQ) (Chart ).…”