Organic Functional Materials And Organic Crystal Structure

This thesis is composed of two parts: (1) Preparation and properties of organic functional materials including electroluminescence materials, electrical bistable materials and rectification materials. (2) Study of organic crystal structure.Since the electroluminescence materials based on our national patents are very scarce, our main work is focused on the development of new materials. Several materials was synthesized, such as electron transport and host emitting materials: organometallics, oxadiazole and quinoline derivatives; hole-transport materials: aromatic amines H40, H41; and star-shaped molecule materials TPM, TIM etc. Some organic lighting-emitting diodes were prepared, which emit red, green and yellow light. The device of ITO/H40/Alq3/LiF/Al reached a luminance efficiency of 1.8cd/A at a drive voltage around 9V, current density of 150 mA/cm2 and a luminance of 1000 cd/m2, and a maximum luminance of 10300cd/m2 at a drive voltage of 14V. At the current density of 20 mA/cm2, and an initial luminance of 150cd/m2, the device of ITO/H40/Alq3/Mg:Ag showed extrapolated life of over one hour without any seal at room temperature.A series of novel quinoline derivatives with polyaromatic system and special Donor-Acceptor structure, are obtained. They show high melt points and thermal stability, and promise themselves as a type of good molecular materials, e.g. in the field of organic light-emitting-diodes (OLEDs). An extraordinary phenomena is described in the normal condensation of arylaldehydes with arylethylidenemalono-nitriles, which had never reported; and the results indicate that another important reaction process, ring closure reaction, can operate in this traditional reaction.The existing organic electrical bistable materials showed some shortcomings, such as low melt point, poor thermal stability, unsuitability for working in room temperature, tend to be crystal, etc. Most of the films based on these materials can't be erased, especially electrical erased, after been written. Our efforts are concentrated on finding high efficient, good stability and electrical writing-erasing materials. A series of organic electrical bistable materials, such as BN4> ONCN and DBCN, was designed and synthesized. The device of Ag/BN4/Al had interesting electrical property, it appears high resistance (37M) under high voltage (>5V) and low resistance ( 102 ) under low voltage (<3V), the rate of resistance reach 105. In the best result, the device can write-read more than 2000 times, so it can be used for ultrahigh-density storage.Organic materials of D- - A type, such as MR-X, PPSC, was designed and synthesized. The molecular devices base on MR-X have good electrical rectification, such as Cu/MR-X/Cu has a ratio of the rectification of over 100, and Cu/MR-1/Ag can reach 10000. Analogous to the structure of MR-X, the molecular materials of PPSC, with a special thiol group, was designed and synthesized. A device of Au/ PPSC/Au, with signal layer of ordered rectification molecular by the self-assembled effect of thiol and the Au film, was prepared. A ratio of the rectification of 1.87 was obtained. Though the result was not so good, a general understanding of the problems lying in the manufacture process of the device was gotten.We found the symmetry was destroyed or decreased in the crystal structure of symmetrical star-shaped molecules, such as tetra((4-cyanophenoxy)methyl)-methane, tetra(N-pyrrolemethyl)methane, and a center of charility was self-formed. The phenomena was discussed by analyzing the intermolecular hydrogen-bonding interactions of tetra((4-cyanophenoxy)methyl)-methane. What's more, we also found that di(4-phenylpiperazin-l-yl)methane has Z' = 4 structure without obvious pseudosymmetry. The structure contains a center carbon, which was different from most of the molecules with Z' >1.In summary, above 100 compounds have been prepared, most of which has special functions. The results based on these organic materials had reached advanced level in our reach field. Furthermore, we found that, charility c...