Design, Synthesis And Properties Research Of Novel Naphthyl Polycyclic Molecules

Organic photoelectric materials have been widely used in organic solarcells, organic field effect transistors, organic light-emitting diodes and so on,due to their excellent photoelectric properties. As an important part of thephotoelectric materials, development of the molecular design and synthesishave become one of the hottest topics. Organic photoelectric materialsinclude p-type and n-type according to being different charge (hole orelectron) carriers. Although organic photoelectric materials has been fullydeveloped, they still have some drawbacks, such as poor solubility and lowerintermolecular packing, limiting their charge transport abilities. In recentyears, the incorporating heteroatoms (sulfur, nitrogen, oxygen) into the rigidbackbone of organic molecules is an effective way to improving themolecular physical properties, for achieving high-performance organicoptoelectronic devices.In this paper, we used naphthyl as the key building block, design andsynthesis of a series of novel oxygen-containing heterocyclic organic small molecules: naphtho[2,1-b:6,5-b’] bisbenzopyran8a, naphtho[2,1-b:6,5-b’]bis-naphthopyran8b, naphtho[2,1-b:6,5-b’]bis[2-(5-hexyl thienyl)]benzopyran8c etc. These molecules have good solubility and stability. As a result of theexistence of pyran moiety, the rotation of molecular conformation is limited,which can improve the rigidity of the molecular plane and conjugated effect,and thus reducing the molecular energy band gap. The peripheral decorationusing substituted group, e.g. alkyl group, will produce great influence notonly on the molecular packing but also on the molecular photoelectricproperties.Their UV-vis spectra showed the absorption maxia at370-400nm, andtheir fluorescene spectra exhibited the emission maxia in the range of417-462nm. The increased conjugated systems for these compounds causedremarkable red shifts in both of their absorption and emission maxima,indicative of their rich optical properties. The electrochemical behaviors ofcompounds8a-8c show their typical p type semiconductor characters. Thedecorated alkyl chains enable to tune the energy levels of HOMO andLOMO, then influence the electric properties of the molecules.