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Synthesis And Property Characterization Of Novel Fluorescent Probes Based On Rhodamine B

Posted on:2017-03-23Degree:MasterType:Thesis
Country:ChinaCandidate:W J YuanFull Text:PDF
GTID:2311330488997400Subject:Spice Flavor Technology and Engineering
Abstract/Summary:PDF Full Text Request
Based on Rhodamine's "OFF-ON" effect, this paper selects Rhodamine B as the fluores-cent group, and through the hydrazine hydrolysis reaction with hydrazine hydrate, Rhodamine B hydrazine is synthesized as the raw material. Eventually, we design and synthesis four rho-damine B derivatives confirmed by MS and NMR. By UV absorption and fluorescence spec-tra, the influence of different recognition groups on the recognition performance of Rhoda-mine B derivatives was studied. The main contents are as follows:? R1 is obtained by direct connect of Rhodamine B hydrazine and 4-Bromobenzaldehyde. It has no ability to identify metal cations. But it is sensitive to pH and has a fast, stable and reversible recognition characteristic under the condition of acid and al-kali.? R2 is obtained by connected with a methoxybenzaldehyde and can effectively iden-tify Hg2+. The UV emission maximum absorbance and fluorescence intensity is significantly enhanced, the fluorescence intensity increases more than 15 times, and the color change from colorless to purple red. Using Job-Plot photometric titration method we obtain the complexa-tion ratio of 1:1, the binding constant is 1.43×10-5 L/mol, the minimum detection limit for 12.5×10-6 mol/L. It can be predicted that it has the possibility of detecting Hg2+as a fluores-cent probe applied in the environment.? 1,2-Diaminobenzene is used as the recognition group. R3 is selective for bothAg+ and Cu2+, and accompanied by a change in color from colorless to pink, so therewill be in-terference in the actual detection applications. In separate experiments of recognition of Ag+, maximum ultraviolet absorbance and fluorescence emission intensity are obviously enhanced, and the fluorescence intensity increased more than 25 times, the complexation ratio is 1:1, the binding constant is 4.16×104 L/mol, the minimum detection limit is 4.3 ×10-6 mol/L.? 2-amino-5-thiol-1,3,4-thiadiazde is applied as the recognition group. R4 can highly selectively recognize Cu2+, without interference of other ions. Maximum ultraviolet absorb-ance and fluorescence emission intensity are obviously enhanced, and the naked eye recogni-tion from colorless to red is achieved. The complex ratio is 1:1, the binding constant is 4.45×104 L/mol, the minimum detection limit is 8.4×10-6mol/L. It can be predicted that R4 has the possibility of detecting Hg2+ as a fluorescent probe applied in the environment and biology.
Keywords/Search Tags:Fluorescent sensor, Rhodamine B derivative, "OFF-ON", Ion recognition
PDF Full Text Request
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