| In recent years, organic π-conjugated materials have emerged as key players in the development of new generations of organic-based devices such as organic light-emitting diodes (OLEDs), organic optoelectronic devices, organic field-effect transistors (OFETs), organic biochemical sensors, organic optical pumped lasers and molecular electronic junctions. Organic π-conjugated materials have drawn great attention of a great many researchers due to their unique optical and electronic properties as well as a large number of advantages including wide availability, low cost, light wight, processibility and structure flexibility. Therefore, exploring novel organic functional materials and study their relationships between the molecular structure, photophysical, electrochemical, optical, electronic and organic thin-film self-assemble morphological properties are still the major challanges. In this paper, we successfully designed and synthesized two novel classes of organic functional materials containing C-C triple bonds through the integration of DFT calculation and experimental technique, and further studied their photophysical, electrochemical and organic thin-film self-assemble morphological properties in order to reveal their structure-property relationships.(ⅰ) we synthesized four linear molecules based on4,4’-diethynyl-1,1’-biphenyl and eleven phenyl-oligothiophene derivatives containing acetylenic spacers such as4-ethynyl-4’-((perfluorophenyl)ethynyl)-1,1’-biphenyl (DYE-Ⅰ),4-ethynyl-4’-((2,3,4,5-tetrafluorophenyl)ethynyl)-1,1’-biphenyl (DYE-Ⅱ),2-((4’-ethynyl-[1,1’-biphenyl]-4-yl)ethynyl)pyridine (DYE-Ⅲ), trimethyl((4-((4-((4-((trimethylsilyl)buta-1,3-diyn-1-yl)phenyl)ethynyl)-[1,1’-biphen-yl]-4-yl)ethynyl)phenyl)ethynyl)silane (TEPEB),5-(phenylethynyl)-2,2’:5’,2"-terthiophene (PE3T),5-(phenylethynyl)-2,2’:5’,2":5",2’"-quaterthiophene (PE4T),4-([2,2’:5’,2"-terthiophen]-5-ylethynyl)aniline (3TEA),4-((5’-iodo-[2,2’-bithiophen]-5-yl)ethynyl)aniline (I2TEA),4-((5’-(phenylethynyl)-[2,2’-bithiophen]-5-yl)ethynyl)aniline (2TBEA), 4,4’-([2,2’-bithiophene]-5,5’-diylbis(ethyne-2,1-diyl))dianiline (2TBDA),4-((5"-iodo-[2,2’:5’,2"-terthiophen]-5-yl)ethynyl)aniline (I3TEA),4,4’-([2,2’:5’,2"-terthiophene]-5,5"-diylbis(ethyne-2,1-diyl))dianiline (3TDDA),1,3,5-tris((5-((trimethylsilyl)ethynyl)thiophen-2-yl)ethynyl)benzene (TETEB),4,4’-bis([2,2’:5’,2"-terthiophen]-5-ylethynyl)-1,1’-biphenyl (B3TEB) and1,3,5-tris([2,2’:5’,2"-terthiophen]-5-ylethynyl)benzene (T3TEB).(ⅱ) The structural modifications at one side of4,4’-diethynyl-1,1’-biphenyl have significant effects on the intermolecular interaction, photophysical, electrochemical and organic thin-film self-assemble morphological properties. Compared with DYE-Ⅱ, DYE-Ⅰ showed more stable due to the effect of perfluorophenyl. Three compounds in the solid state exhibited the formation of J-aggregation and showed high flexibility proved by optical properties, OM pictures and powder XRD analysis. In the type of J-aggregation, two adjacent molecules present close head-to-tail alignment to each other and show weak intermolecular interaction. Three aggregation-induced emission (AIE) fluorescent molecules possessed quite high fluorescence and unusual photoluminescence (PL) emission characteristics, the PL intensities firstly increased and then decreased with the concentration of gradually increased. The typical behaviours induced by the notorious aggregation-enhanced emission (AEE) effect and aggregation-caused quenching (ACQ) effect. Three compounds showed irreversible redox properties. This phenomenon suggested that three compounds have strong antioxidant capacity. All the surface self-assembly morphology of three dyes possess well-fined microstructures with well-ordered lamellas and plate-like grains in good connectivity. The well-ordered self-assembly systems suggest that they have high charge-carrier mobilities. DYE-Ⅰ displayed more intriguing self-assembly properties than those of DYE-Ⅱ and DYE-Ⅲ. This was caused by’fluorophobic effect’, which exhibited strong phase separation between the aromatic core and the fluorinated aromatic periphery.(ⅲ) Compounds PE3T, PE4T,3TEA and I2TEA have good thermal stability. The potential liquid-crystalline property of compounds PE3T is illustrated by DSC, POM and XRD. The long wavelength absorption band of four compounds in solid powder states was greatly blue-shifted in comparison of the absorption spectra in the solution. This could be explained by the aggregation morphology as H-aggregation. H-aggregation, two interacting molecules have their long axes aligned parallel to each other and represent close side-to-side alignment in solid states, as well as show strong intermolecular interaction. It is well worth noting that3TEA exhibits much stronger fluorescence intensity than that of the others because of the presence of the amino mesogen and the stronger hydrogen bonding.3TEA exhibited the typical fluorescence behaviours induced by AEE and ACQ effects. I2TEA exhibited fluorescence quenching. This may be due to the "heavy atom effect" such as iodine in the aromatic ring. Electrochemical results suggested that four compounds have strong antioxidant capacity. All the surface self-assembly morphology of four compounds have well-fined microstructures with well-ordered lamellas and plate-like grains in good connectivity confirmed by AFM. XRD results further revealed that these compounds were well-ordered and highly crystalline.3TEA exhibited the surface self-assembly morphology due to the molecular nature and strong hydrogen bonding.(iv) Compounds2TBEA,2TBDA and TEPEB exhibited the typical fluorescence behaviours caused by AEE and ACQ effects. D-π-A-π-D structured2TBDA based on NH2as donor units and2T as acceptor units with acetylenic spacers π-conjugated chain between them exhibits excellent luminescent properties. The OM images suggested that J-type self-assembly of three compounds occurred. The self-assembled microstructures with well-ordered lamellas and plate-like grains in good connectivity of2TBEA and2TBDA exhibited high performance on the thin-film confirmed by SEM and AFM. TEPEB self-assembled into smooth-faced tube-shaped1D microstructures caused by the strong intermolecular interaction. Futhermore, XRD results also revealed that these compounds were well-ordered and highly crystalline.(v) I3TEA exhibited fluorescence quenching induced by the heavy atom effect.3TDDA with unique D-π-A-π-D structure exhibits excellent luminescent properties. Novel organic π-conjugated star-shaped molecule TEPEB exhibited strong UV-vis absorption and fluorescence emission properties. Three AIE-active molecules showed the typical fluorescence behaviours resulted from AEE and ACQ effects. Three compounds exhibited different UV-vis absorption and fluorescence emission properties in various solvents. Their electrochemical and DFT results demonstrated that three compounds possessed strong antioxidant capacity and good electrochemical properties. Iron, cobalt and nickel belong to Ⅷ family of transition metals. As one of the most widely applied metals, iron, cobalt and nickel have attracted a great deal of attention of researchers in the modern synthetic cheimistry because of wide availability, low cost, low toxicity and friendly environment. Trimethylphosphine is a kind of good ligand with the advantages of strong ability of coordination, convenient preparation and good spectral performance. Iron, cobalt and nickel complexes supported by trimethylphosphine exhibited so high chemical reaction activity that they can easily cut C-H and C-Cl bonds and realize functional reaction.Main contents of this dissertation are shown as below:1. we have presented our new strategy, a novel procedure of salicylaldehydes for the first time that the reaction of sulfur with the Grignard reagent of the acetal for the protection of the aldehyde group affords the title compounds through hydrolysis with dilute hydrochloric acid in the high yields. The introduction of our new methods have overcome the limitations of these traditional methods such as poor yields, strict operations, vigorous reaction conditions, undesired side products, difficult purifications, tedious work-up, the use of hazardous phosphine ligands, and the use of sulfur-containing reagents such as benzenethiols which generally have such a strong, foul smell that working with them can be extremely unpleasant.2. The activation of Csp-H bond was successfully realized by reaction of complex Co(PMe3)4Me supported by trimethylphosphine with9-ethynyl anthracene, and we further studied the properties of the C-H bond activation product.3. We comprehensively studied the properties and chemical reactivity of sulfur coordinated acyl(hydrido)cobalt(Ⅲ) complex through complex Co(PMe3)4Me supported by trimethylphosphine reacted with thiosalicylaldehyde. The properties of sulfur-containing acyl(hydrido)cobalt(Ⅲ) complex was studied and afforded a series of novel sulfur coordinated organocobalt complexes supported by trimethyphosphine ligands. These complexes were fully characterized with IR, NMR and single-crystal X-ray diffraction. We further studied the hydrosilylation catalysis of aldehyde and ketone groups to useful alcohol through hydride transfer using our cobalt(Ⅲ) hydride species as the catalyst. In these reactions, our catalyst exhibited high chemical reactivity. The possible catalytic cycles of the hydrosilylation reactions were well discussed.4. The aliphatic vinylic C-Cl bond activation was successfully realized by cobalt and nickel complexes supported by trimethylphosphine, and the C-Cl bond activation products were isolated and characterized by IR, NMR and single-crystal X-ray diffraction.5. We comprehensively studied the hydrosilylation catalysis of aldehyde and ketone groups to useful alcohol through hydride transfer by our iron(Ⅱ) hydride species as the catalysts. The iron(Ⅱ) hydride complexes were synthesized by complex Fe(PMe3)4reacted with benzenethiols. In these catalytic reactions, our catalysts iron(Ⅱ) hydrides exhibited high chemical reactivity, and we obtained high GC yields of the ultimate hydrolysis products. |
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