Molecular Design,Crystal Preparation And Characterization Of Organic Cocrystals Donor

Organic cocrystal is a kind of molecular-ordered assembly with specific structure formed by molecular recognition between different kinds of molecules. The synergistic effect and aggregation effect stemmed from multi-components, might give better optical and electrical properties than the single compnent. Organic cocrystal provides a novel strategy for the synthesis of novel multifunctional luminescent materials, with potential applications in photoconductivities, bipolar field-effect transistors, ferroelectric. The organic cocrystals were mainly formed by the intermolecular interaction between the electron donor(fused ring aromatic hydrocarbon, tetrathiafulvalene, porphyrin and their derivatives) and the acceptor(TCNQ, TCNB). It is important to design and synthesize novel donor molecular structures in the preparation and development of cocrystal. In this paper, chalcones and Schiff bases of polycyclic aromatic hydrocarbons were used as donor skeletons of cocrystal. Some achievements have been made as the following:Two series of 2'-hydroxychalcone were synthesized from the reactions of aromatic aldehydes(4-Dimethylaminobenzaldehyde, 9-anthracene aldehyde) with four kinds of hydroxyacetophenones(2-hydroxyacetophenone, 4-methoxy-2-hydroxyacetophenone, 4-fluoro-2-hydroxyacetophenone and 4-chloro-(4-dimethylamino)-2-hydroxychalcone). These chalcone derivatives were used as cocrystal donors. The 4-dimethylaminochalcones with planar molecules, and strong solid-state luminescence, showed amplified spontaneous emission phenomenon. The anthracene chalcones had distorted skeletons, thus anthracene chalcones' solid-state luminescence weaker than the 4-dimethylaminochalcones.Five Schiff bases were synthesized from the reaction of polycyclic aromatic hydrocarbons- aldehy-de(1-naphthaldehyde and 9-anthracene aldehyde) with three amines(aniline, p-phenylenediamine and 1,5-naphthalene diamine), which can be acted as donors. The influence of reaction time and yield was mainly explored by utrasonic method. The results showed that the reaction time was reduced from 8 h to 2-4 h. The reaction yield was 44.1%-85% by heating, while the yield of ultrasonic assisted method can be as high as 83.8%-91.6%.In this paper, the charge-transfer complexe was prepared by using(E)-1-(4-N, N-dimethylamino)phenyl-3-anthracenylchalcone(E2) as the electron donor and TCNQ as the acceptor. Single crystal X-ray diffraction analysis showed that the cocrystal were composed of chalcone and TCNQ in 1:1 ratio, with the distorted anthracene ring of chalcone. When the complexe with multi-hydrogen bonds were prepared by 1,10-phenanthroline-5,6-dione and o-phenylenediamine. This kind of hydrogen bonding cocrystal was composited by bis-Schiff base product 4,5,9,14-tetraaza-benzo[b]triphenylene(DPPZ) and o-phenylenediamine, in which the ?-? interaction between DPPZ molecules are arranged along b-axis direction.