This critical review discusses specific chemical and physicochemical requirements which must be met for organic compounds to be considered as promising materials for applications in organic electronics. Although emphasis is put on molecules and macromolecules suitable for fabrication of field effect transistors (FETs), a large fraction of the discussed compounds can also be applied in other organic or hybrid (organic-inorganic) electronic devices such as photodiodes, light emitting diodes, photovoltaic cells, etc. It should be of interest to chemists, physicists, material scientists and electrical engineers working in the domain of organic electronics (423 references).

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Three groups of naphthalene bisimides were synthesized and comparatively studied, namely, alkyl bisimides, alkylaryl ones, and novel bisimides containing the alkylthienyl moiety in the N-substituent. The experimental absorption spectra measured in CHCl(3) exhibit one intensive absorption band that is uniformly detected in the spectral range of 340 to 400 nm for all studied molecules. This band consists of three or four vibronic peaks. The introduction of an alkylthienyl group results in the appearance of an additional band (in the spectral range from 282 to 326 nm, depending on the position of the substituent) that can be ascribed to the pi-pi* transition in the thienyl chromophore. The minimal substituent effect on the lowest electronic transitions was explained using the quantum chemical calculations based on the time-dependent density functional theory. The investigation of the shapes of frontier orbitals have also shown that the oxidation of bisimides containing thiophene moiety is primary connected with the electron abstraction from the thienyl ring. To the contrary, the addition of an electron in the reduction process leads to an increase in the electron density in the central bisimide core. As shown by the electrochemical measurements, the onset of the first reduction potential (so-called "electrochemically determined LUMO level") is sensitive toward the type of the substituent being shifted from about -3.72 eV for bisimides with alkyl substituents to about -3.83 eV for alkylaryl ones and to about -3.94 eV for bisimides with thienyl groups. The presence of the thienyl ring also lowers the energy difference between the HOMO and LUMO orbitals. These experimental data can be well correlated with the DFT calculations in terms of HOMO/LUMO shapes and energies. Taking into account the low position of their LUMO level and their highly ordered supramolecular organization, the new bisimides are good candidates for the use in n-channel field effect transistors, operating in air. The fabricated "all organic" transistors show effective charge carrier mobilities in the range 10(-2) to 10(-4) cm(2) V(-1) s(-1) and the ON/OFF ratios exceed 10(5) for the majority of cases.

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Polyarylamine containing meta-para-para-aniline units in the main chain and meta-para-aniline units in the pendant chains was synthesized. The polymer can be oxidized to radical cations in chemical or electrochemical ways. The presence of meta-phenylenes in the polymer chemical structure allows for the ferromagnetic coupling of electronic spins, which leads to the formation of high spin states. Detailed pulsed-EPR study indicates that the S = 2 spin state was reached for the best oxidation level. Quantitative magnetization measurements reveal that the doped polymer contains mainly S = 2 spin states and a fraction of S = 3/2 spin states. The efficiency of the oxidation was determined to be 74%. To the best of our knowledge, this polymer is the first example of a linear doped polyarylamine combining such high spin states with high doping efficiency.

The role of the substitution of electron acceptor/donor groups on the photophysical properties of TSANs was investigated. The obtained results allow us to verify the dependence of the multiple emission bands on the functionalization of the TSAN core.

New tetraester derivatives of 1,4,5,8-tetraazaanthracene have been prepared and characterized by spectroscopic and electrochemical techniques. The LUMO level of the compounds is close to -4 eV (the so-called air operating stability border in n-channel field effect transistors). Tetraesters were obtained with reasonable yields without the necessity of using high-quality reactants or solvents, resulting in their low cost.

An in-depth analysis of the electro-optical and light emissive properties was carried out with a new fused heteroacene, the bis [(1,2)(5,6)] indoloanthracene. The compound was synthesized in a straightforward bidirectional manner from 1,4-dibromo-2,5-diodobenzene utilizing a reaction cascade of isomerisation and cyclisation sequences. Bis-[(1,2)(5,6)] indoloanthracene exhibits bright luminescence with high quantum yield in solution as well as in the solid state. By using this novel semiconductor as active layer, an efficient OLED has been fabricated for which its emission pattern resembles at least two emitters in a single emissive region originated from the same molecule. One has its origin from the single molecule and is similar to the luminescence spectra in solution, whereas the other functions through the formation of aggregates being similar with the emission pattern found with crystals of bis-[(1,2)(5,6)]indoloanthracene. As a result bright sky-blue OLEDs with very high luminance exceeding 10000 cd/m 2 were obtained. Such color pattern and performance has not previously been observed with low molecular weight, electron-rich fused polycyclic aromatic compounds and indicate a promising new class of materials for development.