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.
A material comprising an electron-accepting unit of formula (I): wherein Ar1 and Ar2 independently is a 5- or 6-membered aromatic or heteroaromatic ring or is absent; and each X is independently H or a substituent with the proviso that at least one X is an electron-withdrawing group and wherein X groups bound to adjacent carbon atoms may be linked to form an electron-withdrawing group. The material further comprises an electron-donating unit D comprising a fused or unfused furan or thiophene. The material may be a polymer comprising repeat units of formula (I). The material may be a non- polymeric compound. An organic photodetector may contain a bulk heterojunction layer containing an electron acceptor or an electron donor wherein at least one of the electron acceptor and electron donor contains a unit of formula (I).
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.