Synthesis And Properties Of Low-molecular-weight Organogelators Containing Three Long-chain Alkoxy Substituents

The supramolecular has become the international front topic and attracted much attention in the study of molecular science in recent years and organogel has become a hot research in the field of supramolecular chemistry for its simple preparation method and the controllable microstructure.The organic gelators can self-assemble into various dimensional and morphologic superstructures in organic solvents directed by non-covalent bonding interactions,such as H-bonding,van der Walls,Ï€-Ï€stacking ect.Functional organogel with special structures can be constructed by introducing some functional groups to the organogelators.Designing and synthesizing organic gelators with simple structure is the main purpose of this thesis.The ability of the synthesized compouds to form organogel in different organic solvents is investigated.Their molecular structures are confirmed by ~1H NMR,IR and UV-Vis spectra etc.In the first part,the progress in the study of organogel is briefly reviewed,including the definition and classification of the low molecular-mass organic gelator(LMOG);the methods for the characterization of the self-assemble of organogel at the molecular level;and the applications of LMOG in bio-catalysis,biomembrane analog,extraction process, supramolecular template,drug release,solar cells and so on.The second part focused on the synthesis and characterization of the following compouds:1) A series of benzoic esters containing three long-chain alkoxy substituents are synthesized from gallic acid and straight-chain alcohols with different length.2) The compounds containing three long-chain alkoxy groups,azophenyl group and cholesteryl group are obtained from ethyl 3,4,5-Tris(n-hexadecan-1-yloxy) benzoate;3)The compounds with bifunctional groups of spiropyran and azophenyl are synthesized by the reaction of N-methyl-2,3,3-trimethyl-3(H)-indole and ethyl 4-(3-formyl-4-hydroxyphenylazo)benzoate.In the third part,the ability of synthesized compouds to form organogel is tested.It is shown that the compounds fioom 3a to 3j can gel aromatic amines solvents such as aniline and the stability of the organogel system decreases with the lengthening of the alkoxyl chains;the organogels fromed by 3a-3j are not stable in some solvents such as pyridine,morpholine, quinoline and DMF.The compound 4a can also gel aromatic amines solvents such as aniline, and thc stability of the organogel is much more stable than those formed by 3a-3j in the same solvent;but the organogels formed by 4a in certain solvents such as pyridine,morpholine, quinoline and DMF are not stable;The gelation ability of compound 4b is similar to the compounds 3a-3j.The spectra properties of compounds 4a,5a and 5b are studied and it's found that they are all sensitive to light and heat;compounds 5a and 5b are also sensitive to pH.