【摘要】：我們設(shè)計并合成了兩個基于ICT和CHEF機理的熒光傳感器H_2L~1(肟基)和H_2L~2。H_2L~1是一個四齒雙功能配體,并且它可以合成四核的配合物。傳感器H_2L~1和H_2L~2由于分子內(nèi)PET機理而表現(xiàn)出較低的比色熒光,當(dāng)按照一定比率加入Zn~(2+)后,溶液的熒光發(fā)射強度增強,產(chǎn)生熒光響應(yīng),隨著Zn~(2+)濃度的降低,熒光發(fā)射強度減弱。實驗結(jié)果表明,該傳感器對Zn~(2+)的熒光選擇性較強,超過其他金屬離子,尤其是Cd~(2+)。據(jù)報道,Cd~(2+)和Zn~(2+)有相似的化學(xué)特性,易產(chǎn)生干擾,傳感器H_2L~1可用于對Cd~(2+)和Zn~(2+)的選擇性識別,此外,傳感器H_2L~2可以對Cu~(2+)進(jìn)行選擇性識別。傳感器H_2L~1的結(jié)構(gòu)表明它可以和多種金屬離子配位形成穩(wěn)定的配合物,配體分子的設(shè)計具有雙N2O2螯合基團(tuán),使它可以與四個金屬離子配位,紫外-可見光譜中觀察到的四個等位點進(jìn)一步證實了這個結(jié)論,結(jié)果表明它們的化學(xué)計量比為1:1。Zn~(2+)和Ni~(2+)分別與傳感器H_2L~1以1:1的配比形成穩(wěn)定的配合物,并且它們都是五配位的構(gòu)型。Zn~(2+)和Ni~(2+)與H_2L~1所形成的配合物的熒光光譜、紫外-可見光譜和晶體結(jié)構(gòu)都證實了Zn~(2+)和Ni~(2+)與傳感器H_2L~1的配位比為1:1。斯托克位移是衡量熒光靈敏度的一個很重要的指標(biāo),傳感器H_2L~1識別Zn~(2+)時,有一個很大數(shù)值的斯托克位移,使得這個識別效果非常明顯�？偟膩碚f,這兩個傳感器表現(xiàn)出高靈敏的選擇性和化學(xué)可逆性,所以,它們可以被應(yīng)用到生物和環(huán)境系統(tǒng)中對Zn~(2+)和Cu~(2+)進(jìn)行選擇性識別。[H_2L~1]?C_6H_3N_3O_7:化學(xué)組成為C22H19N5O10,Mr,513.42,屬于三斜晶系,空間群P-1,晶胞參數(shù):a=7.214?,b=14.102?,c=14.279?,α=114.563°,β=91.226°,γ=99.421°,Z=2,V=1296.9?3,R1=0.1437,wR2=0.2706.[Zn_4(L_4)]:化學(xué)組成為,C_(64)H_(56)N_8O_(12)Zn_4,Molecular weight,1390.73,屬于四斜晶系,I41/a,Cell parameters:a=21.9438(3)?,b=21.9438(3)?,c=12.4417(3)?,α=90°,β=90°,γ=90°,Z=4,V=5991.1(2)?3,R1=0.0525,wR2=0.1497.[Ni_4(L_4)]:化學(xué)組成為C_(64)H_(56)N_8O_(12)Ni_4,Molecular weight,1363.93,屬于三斜晶系,P-1,Cell parameters:a=13.2898(8)?,b=14.7012(8)?,c=16.7421(9)?,α=81.534(5)°,β=67.214(5)°,γ=72.519(5)°,Z=2,V=2874.7(3)?3,R1=0.0759,wR2=00.1220.[H_2L~2]:化學(xué)組成為C_(15)H_(13)NO_3,Molecular weight,255.26,屬于單斜晶系,P 21/c,Cell parameters:a=7.5158?,b=6.3940?,c=25.881?,α=90°,β=93.243°,γ=90°,Z=4,V=1241.8?3,R1=0.0547,wR2=0.1350.
[Abstract]:We designed and synthesized two fluorescent sensors H_2L~1 and H_2L~2.H_2L~1 based on ICT and CHEF mechanism, which are four-toothed bifunctional ligands, and they can synthesize tetranuclear complexes. The sensors H_2L~1 and H_2L~2 showed low colorimetric fluorescence due to the mechanism of intramolecular PET. When Zn~ (2) was added at a certain ratio, the fluorescence emission intensity of the solution increased and the fluorescence response was produced, with the decrease of Zn~ (2) concentration. The intensity of fluorescence emission is weakened. The experimental results show that the fluorescence selectivity of the sensor for Zn~ (2) is stronger than that of other metal ions, especially Cd~ (2). It is reported that Cd~ (2) and Zn~ (2) have similar chemical properties and are prone to interference. The sensor H_2L~1 can be used for selective identification of Cd~ (2) and Zn~ (2). In addition, The sensor H_2L~2 can selectively identify Cu~ (2). The structure of the sensor H_2L~1 shows that it can coordinate with a variety of metal ions to form stable complexes. The ligand molecules are designed with double N2O2 chelating groups so that they can coordinate with four metal ions. This conclusion is further confirmed by four equal sites observed in UV-vis spectra. The results show that their stoichiometric ratios are 1 鈮，

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