Organic Donor-Acceptor Complexes As Potential Semiconducting Materials

In this review article, the synthesis, characterization and physico-chemical properties of the organic donor-acceptor complexes are highlighted and a special emphasis has been placed on developing them as semiconducting materials. The electron-rich molecules, i. e., donors have been broadly grouped in three categories, namely polycyclic aromatic hydrocarbons, nitrogen heterocycles and sulphur containing aromatic donors. The reactions of these classes of the donors with the acceptors, namely tetracyanoquinodimethane (TCNQ), tetracyanoethylene (TCNE), tetracyanobenzene (TCNB), benzoquinone, pyromellitic dianhydride and pyromellitic diimides, fullerenes, phenazine, benzothiadiazole, naphthalimide, DMAD, maleic anhydride, viologens and naphthalene diimide are described. The potential applications of the resulting DA complexes for physico-electronic purposes are also included. The theoretical investigation of many of these products with a view to rationalise their observed physico-chemical properties is also discussed.

Synthesis and crystal structure of the novel chiral acetyl-3-thiophene-5-(9-anthryl)-2-pyrazoline, C23H18N2OS

C23H18Cl4N2OS, orthorhombic, P212121 (no. 19), a = 16.872(3) Å, b = 10.414(2) Å, c = 10.589(2) Å, V = 1860.5(6) Å3, Z = 4, R gt (F) = 0.0588, wR ref (F 2) = 0.1464, T = 293 K.

Polycyclic motif engineering in cyanostilbene-based donors towards highly efficient modulable emission properties in two-component systems

Cynostilbene based two-component materials are fabricated which exhibit tunable structures and excellent photophysical properties depending on the IP of the polycyclic moiety and organization of the donor-acceptor in the condensed phase.

Crystal structure of 1-(5-(anthracen-9-yl)-3-(4-hydroxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl)propan-1-one, C26H22N2O2

C26H22N2O2, monoclinic, P21/c (no. 14), a = 16.4367(8) Å, b = 12.7804(6) Å, c = 19.5474(8) Å, β = 96.1700(14)°, V = 4082.5(3) Å3, Z = 8, R gt(F) = 0.0516, wR ref(F 2) = 0.1195, T = 273(2) K.

Crystal Structures and Optical Properties of Two Novel 1,3,5-Trisubstituted Pyrazoline Derivatives

Two novel 1,3,5-trisubstituted pyrazoline derivatives—1-acetyl-3-(4-methoxyphenyl)-5-(6-methoxy-2-naphthyl)-pyrazoline (2a) and 1-(4-nitrophenyl)-3-(4-methoxyphenyl)-5-(6-methoxy-2-naphtyl)-pyrazoline (2b)—were synthesized and their structures were determined by single crystal X-ray crystallography. Both of the two crystals exhibit twisted structures due to the large dihedral angles between the pyrazolinyl ring and the aromatic ring at the 5-position (88.09° for 2a and 71.26° for 2b). The optical–physical properties of the two compounds were investigated. The fluorescent emission of 2b arises from the 1,3-disubstituted pyrazoline chromophores and exhibits a red shift in polar solvents and solid-state, which could be attributed to photo-induced intramolecular charge transfer (ICT) from N1 to C3 in the pyrazoline moiety and the intermolecular interactions within the crystal. The fluorescent emissions of 2a (λmax 358–364 nm) in solvents and solid-state both come from 6-methoxy-2-naphthyl chromophores, which are fairly insensitive to the solvent polarity.

Supramolecular helical nanostructures from self-assembly of coil-rod-coil amphiphilic molecules incorporating the dianthranide unit

Coil-rod-coil amphipathic oligomers composed of a rigid dianthranide unit and a hydrophilic branched oligoether as the coil segment were synthesized. These amphiphilic molecules self-assemble into clew-like aggregates composed of fibres or helical nanofibers in aqueous solution. Subsequently, supramolecular polymers were produced from the above objects through charge-transfer interactions by adding 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (4F-TCNQ). Interestingly, temperature-sensitive supramolecular chirality was induced by lateral methyl units located at the interface of the rigid and flexible segments. However, upon addition of the electron-acceptor molecule, 4F-TCNQ, strong donor-acceptor interactions restrict any change in supramolecular chirality with temperature.

Crystal structure of (S)-1-(5-(anthracen-9-yl)-3-phenyl-4,5-dihydro-1H-pyrazol-1-yl)propan-1-one, C26H22N2O

C26H22N2O, orthorhombic, Pca21 (no. 29), a = 22.8108(10) Å, b = 9.8328(5) Å, c = 8.7361(3) Å, V = 1959.45(15) Å3, Z = 4, R gt(F) = 0.0380, wR ref(F 2) = 0.0853, T = 296(2) K.