New Push‐Pull Chromophores Featuring TCAQ (11,11,12,12‐Tetracyano‐ 9,10‐anthraquinodimethane) and Other Dicyanovinyl Acceptors

Abstract

Stable, highly colored push-pull chromophores with NMe 2 donor and C=C(CN) 2 acceptor moieties, featuring intense intramolecular charge-transfer (CT) bands in the UV/Vis spectra, are reported. In an attempt to prepare the quinoid pushpull systems 2, chromophores 10 and 11, with a central cyclohexene spacer, were obtained and characterized by X-ray analysis. A series of donor-substituted TCAQ (11,11,12,12-tetracyano-9,10-anthraquinodimethane) derivatives were synthesized, using the Knoevenagel condensation between appropriately functionalized anthraquinones and malononitrile, mediated by the Lehnert reagent (TiCl 4 /pyridine), as the key step. HCl addition to triple bonds was observed

Solvatochromism as an efficient tool to study N,N‐dimethylamino‐ and cyano‐substituted π‐conjugated molecules with an intramolecular charge‐transfer absorption

“…All the λ max values were converted for further evaluation into the wavenumbers $\tilde {v}_{{\rm max}} $ having energy dimension. The CT character of the longest‐wavelength absorption of compounds 1 – 9 was already confirmed by protonation/neutralization experiments 11–20…”

“…1). 11, 12 Optical properties of these model CT solvatochromic indicators were investigated in 32 solvents of various nature. The resulting data were evaluated by means of theoretical models and (semi)empirical correlations determining the optical properties related to electron distribution and polarizability.…”

Amidophosphine‐stabilized palladium complexes catalyse Suzuki–Miyaura cross‐couplings in aqueous media

“…The cross-coupling reactions were carried out under aqueous conditions (EtOH-water or water) involving Pd(II) catalysts 1-6 (1 mol%)/Na 2 CO 3 system under argon. [34,35] The reactions were monitored using GC analysis and the results are summarized in Table 2. Commercially available [(PPh 3 ) 2 PdCl 2 ] was used as a standard.…”

Synthesis and Physicochemical Properties of Strong Electron Acceptor 14,14,15,15‐Tetracyano‐6,13‐pentacenequinodimethane (TCPQ) Diimide

“…Three peaks are observed in the absorption spectra, which are located at 416, 330, and 295 nm. The maximum absorption wavelength of 1 was the same as that of TCPQ [10] (415 nm in chloroform) and about 69 nm redshifted com- pared to that of TCAQ [17] (347 nm in dichloromethane), which can be ascribed to the enlarged conjugation length of 1. The HOMO-LUMO energy band gap estimated from the initial absorption was 2.79 eV.…”

“…pared to that of TCAQ [17] (347 nm in dichloromethane), which can be ascribed to the enlarged conjugation length of 1. The HOMO-LUMO energy band gap estimated from the initial absorption was 2.79 eV.…”