论文部分内容阅读
The synthesis of three isomers based on Michael addition mechanism for the detection of sulfurcontaining species in aqueous solution is described. These compounds are constructed by conjugating an enone to a coumarin fluorophore. A substituted-phenyl(o, m, or p-) was appended at the carbonyl carbon to adjust the reactivity. The experimental results showed that(E)-7-(diethylamino)-3-(3-(3-hydroxyphenyl)-3-oxoprop-1-en-1-yl)-2H-chromen-2-one(m-QPS) and(E)-7-(diethylamino)-3-(3-(4-hydroxyphenyl)-3-oxoprop-1-en-1-yl)-2H-chromen-2-one(p-QPS) barely react with sulfur-containing nucleophiles, while(E)-7-(diethylamino)-3-(3-(2-hydroxyphenyl)-3-oxoprop-1-en-1-yl)-2H-chromen-2-one(o-QPS) exhibited a fast response toward sulfite, sulfide and thiols in DMSO/phosphate buffer(2:1). The above results are probably due to the intramolecular H-bonding activated Michael addition.More interestingly, cysteine triggered unusual photophysical responses of o-QPS: the original absorption(488 nm) and emission peaks(573 nm) underwent significant blue shifts initially and then recovered,which might be caused by the Michael addition and elimination reaction, respectively.
The synthesis of three isomers based on Michael addition mechanism for the detection of sulfurcontaining species in aqueous solution is described. These compounds are constructed by conjugating an enone to a coumarin fluorophore. A substituted-phenyl (o, m, or p-) was added at the carbonyl carbon to adjust the reactivity. The experimental results showed that (E) -7- (diethylamino) -3- (3- hydroxyphenyl) -3-oxoprop- chromen-2-one (m-QPS) and (E) -7- (diethylamino) -3- (4- hydroxyphenyl) -3-oxoprop- 1 -en- 1 -yl) -2H-chromen-2 -one (p-QPS) barely react with sulfur-containing nucleophiles, while (E) -7- (diethylamino) -3- (2- hydroxyphenyl) -3 -oxoprop-1-en- 2H-chromen-2-one (o-QPS) exhibited a fast response toward sulfite, sulfide and thiols in DMSO / phosphate buffer (2: 1). The above results are probably due to intramolecular H-bonding activated Michael addition. interestingly, cysteine triggered unusual photophysical responses of o-QPS: the original absorption (488 nm) and emission p eaks (573 nm) underwent significant blue shifts initially and then recovered, which might be caused by the Michael addition and elimination reaction, respectively.