Coumarin And Resorufin-based Fluorescent Probes：Molecular Design，Synthesis And Properties

For life safety and disease therapy, it is great significant to develop fluorescentchemosensors for the recognition of heavy meta l ions and b iolo gical s ma ll mo lecules.Coumarin a nd resorufin, both known by the ir exce llent spectroscopic properties oflarge molar extinctions coeffic ie nt and high fluorescence quantum yie ld, have beenwide ly used in the fie ld of environme nta l scie nce, molec ular bio logy scie nce andmed icine science. In order to improve the shortage of the existe nt fluorescentchemosensors for go ld io ns and hydrogen s ulfide, on basis of the foundatio n ofpredecessor s excellent work, we utilize coumarin and resorufin as fluorescencereporters, ratio nally constructed a convenie nt ratio metric fluorescent probe for Au³⁺and high se lective fluorescent c hemosensor for H₂S. The contents o f this thes isinc lude as fo llowing:1. We rationa lly design an ICT （intamo lecular charge trans fer）-based fluorescentprobe for ratiometric detection of Au³⁺on bas is of7-diethyla mine coumarin. Uponadition of Au³⁺io ns, Au³⁺-med iating the cyclization of propargyla mide to formformylo xazo le, causing the c hange of ICT, accompanying with s hift o f the absorptionand fuorescence spectrum of A. The probe shows good sensitivity and selectivity toAu3+ions. Morover, owing to the intramo lecular hydrogen bond between2-oxo andamide of probe A, the response time to Au³⁺is just about20min, which is about3times faster than most of previous ly reported known fluorescent go ld ion probes basedon the same recognition mo iety.2. Based on the uniq ue bi-nuc leophilic ity characteristic of H₂S, we rationa llyconstrcuted a high se lective fluorescent che mosensor for H₂S. We linked therationa lly designed recognition mo iety2-methylene-succ inic ac id1-methyl ester toresorufin and7-a mino-3-methylcoumarin respectively to get two kinds fluorescentchemosensors for detection o f H₂S. And both probes showed high se lectivity to H₂Sover other rele vant commo n inorganic anions, reactive sulfer species and biothio ls.