Design,Synthesis And Applications Of Functional Organic Small Molecules,Oligomers And Polymers

Organic optoelectronic and electronic functional materials have already been the research highlighting areas compared with the other new high-tech frontiers. Considerable attention has been drawn from both academic and industrial worlds due to their low-cost, fast electro-optical signal response and environmental friendliness, etc. Especially in the area of electronics, optoelectronics, chemical sensors and biosensors, the applications of these functional materials have profound impact in changing and facilitating people’s way of living. This thesis reviewed recent developments of organic molecular logic gates, π conjugated systems based self-assembly, organic photovoltaics etc. Based on which, three projects have been extensively studied as follows:1. Three compounds were designed, synthesized and investigated for logic gate applications as follows:firstly, a9-(Cycloheptatrienylidene)fluorene based D-A system (PACHF) displayed the optical property that the photoinduced electron transfer (PET) process was activated and the emission was turned "off when two receptor units were bound with Fe3+or Cu2+, respectively. Applying Fe3+or Cu2+as an input, A NOR gate was established. Secondly, an Anthracene-bis-Pyridinemethyl-Aniline based system (ANPB) was extensively studied. ANPB showed remarkable selectivities for Zn2+and Cu2+. An INHIBIT and a NOR gates were achieved, repectively. At last, the photophysical and photochemical properties of5-(2-Methoxyphenoxy)-2,2’-bipyrimidine-4,6-diol (MPBD) were also investigated as well. MPBD can exist in three ionization states in THF solution and each of which shows distinct spectral properties. By monitoring at several emission wavelengths, choosing different propotions of tetrabutylammonium hydroxide (TBAH) as two inputs, a "two inputs/three outputs" molecular logic configuration was realized and demonstrated.(Corresponding to Chapter2)2. Two groups of oligo(2,7-fluorene ethynylene)s (FEs) armed perylene bisimide (PBI) derivatives were designed, synthesized and characterized. The linear shaped group PBIF-1-PBIF-3show identical π-π*transition bands of UV-vis spectra from420to556nm in CHCI3solutions because the substituted FEs donot show π electron delocalized due to the nodes at the PBI nitrogen positions. While the "X" shaped PBIF-4-PBIF-6exhibit broad bands of absorption from260nm to650nm arising from the strong π-π conjugation between the FEs substituted at the bay region of PBI and the focal core. Emissions of PBIF-1-PBIF-3centralized at575nm without displaying any wavelength shift but the Φdecreased as the number of substituted FEs units increased. The bay region substituted PBIF-4-PBIF-6show emissions at643nm,659nm and636nm respectively with average stokes’shift of40nm. Nanorods, with average size of150±50nm in width and1.5±0.5μm in length, were self-assembled from PBIF-3in the solution of chloroform and ethyl acetate, which was observed by TEM measurements.(Corresponding to Chapter3).3. Fluorene and spirofluorene based3D conjugated polymer with pendant ionic ammoniums and its linear analogues were designed, synthesized and characterized. Application of these conjugated polyelectrolytes as cathode interfacial layers in organic photovoltaic cells was extensively investigated. The alcohol soluble conjugated polymer interlayers can improve the device performance significantly by simultaneous enhancements of the open-circuit voltage, short-circuit current density, and fill factor. An increasement of PCE from2.62%to4.67%by78%was observed with poly[(2,7,20,70-spirobifluorene-co-(9,9-bis(60-((N,N,N-trimethyl) ammonium) hexyl)-2,7-fluorene) dibromide)] based on PFOTBT-PC61BM blend.(Corresponding to Chapter4)...