Synthesis Of Novel Rhodamine-based Fluorescent Probes And Their Recognition Performance For Fe³⁺,Al³⁺and Cr³⁺

Trivalent metal ions especially Fe³⁺,Al³⁺and Cr³⁺ play an important role in human health.The disorder of Fe³⁺,Al³⁺and Cr³⁺may lead to several diseases such as liver injury,renal failure,diabetes,arteriosclerosis,Parkinson’s disease and so on.Thus,the detection of Fe³⁺,Al³⁺and Cr³⁺ is an urgent need for human health.Among various methods for metal ions detection,fluorescent chemosensors have attracted great attention due to their high selectively,sensitivity,simplicity and direct visualization.In this thesis,several novel rhodamine-based probes has been designed and synthesized.Their recognition performance for Fe³⁺,Al³⁺,Cr³⁺ were also studied.1.Three novel rhodamine-based compounds（P1,P2,P3）were synthesized from rhodamine B through "click chemistry".It is showed that probe P3 acted as a naked-eye and "turm on" fluorescent probe for Fe³⁺,Al³⁺ and Cr³⁺ recognition.P3 is highly selective to trivalent ions(Fe³⁺,Al³⁺ and Cr³⁺)over other monovalent or divalent ions in CH3OH.Detection limits of probe P3 for Fe³⁺,Cr³⁺ and Al+are 9.7×10-5 M、6.9×10-5 M、1.4×10-4 M respectively,which could make it potentially applicable in Fe³⁺,Cr³⁺and Al³⁺detection.2.Rhodamine-based compound P4 and P,were synthesized from rhodamine B hydrazide.Both P4 and P,acted as a colorimetric and fluorescent "turn on" probe for Fe³⁺,Al³⁺ and Cr³⁺ with high selective over other monovalent or divalent ions in CH3OH.Furthermore,probe P4 and P5 exhibited low detection limits toward these trivalent ions(Fe³⁺,Al³⁺and Cr³⁺)3.Rhodamine-based compound P6,P7and P8 were obtained from the reaction between rhodamine B and 2-methoxy-ethylamin,2-（2-methoxyethoxy）ethanamine,2-（2-（2-methoxyethoxy）ethoxy）ethanamine.P6,P7and P8 showed high selectivity and high sensitivity towards Fe³⁺,Al³⁺and Cr³⁺in CH3OH.4.Histidine and glutamate were introduced to rhodamine B to obtain the compounds P9 and P10.Interesting,P10 is highly selective to trivalent ions(Fe³⁺,Al³⁺ and Cr³⁺)over other monovalent or divalent ions in water（Tris,10 mM,pH=7.4）.Furthermore,this change was also accompanied with a naked-eye color variation from colorless to pink after addition of Fe³⁺,Al³⁺ and Cr³⁺.Thus,a colorimetric and fluorescent "turn on" probe for Fe³⁺,Al³⁺ and Cr³⁺ in aqueous medium is obtained.