Studies On The Spectral Properties Of The Porphyrin And Carbazole Derivatives

Photodynamic therapy (PDT) is a recently studied treatment fortumours with distinct features such as lower toxicity and fewer sideeffects, compared to traditional radiotherapy and chemotherapy. It alsocreates barely no wounds after treatment. Photosensitizers, a lot of whichare porphyrin derivatives, play the key role in PDT. Porphyrins areapplied in many other fields, such as molecular recognition, medicinescience, biochemistry, analytical chemistry and material chemistry.Porphyrins not only can go against tumours by being a part of PDT asphotosensitizers, but also can directly interact with DNA to alter the generegulation and expression of tumour cells.Carbazoles are compounds with activity, which can be applied inmany fields. They usually are the synthesis raw materials of industrialdyes, parts of the organic non linear optical materials, stabilizers ofinsecticides, raw materials of resins. Moreover, nature carbazolederivatives can treat tumours or leukeamia significantly. It has been foundthat cationic carbazoles are able to stabilize the G-quadruplex of telomere,inhibit the activity of telomerase, which means potential antineoplasticactivity. Besides, porphyrins, and dicationic carbazole derivatives can beused as two-photon nucleus flusrescent probe.Porphyrins and carbazole derivatives are bioactive moleculars withconjugated system. They both can be used to interact with DNA. Thenovel compounds that come from porphyrins and carbazoles are worthyof study. Among carbazole derivatives, diazacarbazole has not beenresearched much.The evaluation of interaction between compounds and DNA isusually performed by UV-visible spectra, fluorescent emission spectraand circular dichroism spectra. Fluorescent spectra is the main methodapplied here. This thesis is going to introduce the synthesis of the diazacarbazoleand its diiodide, as well as the evaluation of their spectral properties.Three porphyrins are involved to demonstrate their interaction with DNA.All these are treated as the basis of further research on the synthesis andevaluation of a series of novel compounds, which consists of porphyrinsand diazacarbazoles.There are four parts in this thesis:1. The background, development and mechanism of PDT andphotosensitizers, the synthetic route and applications of the porphyrinsand carbazole derivatives;2. The3,6-dimethyl-3,6-diazacarbazole diiodide is obtained by a six-stepsynthesis including N-oxidation, nitration, Ullmann reaction, catalytichydrogenation, cyclization and methylation, the reaction condition ofcatalytic hydrogenation by Pd/C to prepare4,4’-diamino-3,3’-bipyridine has been discussed, all the intermediates and targetmoleculars are confirmed by IR, NMR, and MS;3. The UV-vis and fluorescent characteristics of3,6-diazacarbazole and3,6-dimethyl-3,6-diazacarbazole diiodide are investigated, the changeof fluorescence intensity and lifetime of the three porphyrins beforeand after binding with DNA are investigated;4. The conclusion of this paper, the work still undergoing and thepurpose and expectation of our future work.