英语翻译Fluorescent sensors for anions have been extensively stu

英语翻译
Fluorescent sensors for anions have been extensively studied
since the sensing of fluoride anions is of special interest due to
their importance in biological and industrial systems.7 Recently,
Zˇ
inic´ and co-workers reported on fluoride sensing with
a gel based on oxalamide-derived anthraquinone.8 The gel
showed the color change and the gel-to-sol phase transition in
the presence of fluoride anion,which may provide the basis for
the development of the sensing of fluoride with the naked eye.
In this communication,we designed a low molecular mass
molecule 1 composed of the 2-(20-hydroxyphenyl)benzoxazole
(HPB) unit,urea groups,and long alkyl chains,which could
function as p–p interactions,hydrogen bonding,and van der
Waals interactions,respectively [Fig.1(A)].As already reported
in detail,HPB has two tautomers with two emission maxima of
the enol (weak fluorescence) and keto (strong fluorescence)
forms by excited state intramolecular proton transfer (ESIPT)
(see Scheme S2 in the ESIw).9 The intramolecular hydrogen
bonding in HPB can be altered by the presence of fluoride anion
regardless of its monomeric or polymeric form,which showed a
visually noticeable color change as reported earlier.9b,c Our
interest is focused on the following:(1) gelator 1 adopts a flat
conformation in the aggregation state originating from intramolecular
hydrogen bonding in the HPB unit,which may
induce a facilitated proton transfer between the hydroxyl proton
of benzene ring and the nitrogen of the benzoxazole group;
(2) the hydroxyl groups in HPB are able to selectively interact
with fluoride anions,which may provide the color changes; (3)
the urea moieties are able to bind with fluoride anions; therefore,
intermolecular hydrogen bonding between neighboring
urea moieties would be disrupted in the presence of fluoride
anion,which may bring about the gel-to-sol transition.

用于阴离子的荧光传感器自从氟化物阴离子的传感因为它们在生物系统和工业系统的重要性而具有特别的意义.7 最近,Zinic和他的同事报道了用基于草酰胺衍生的蒽醌的凝胶进行的氟化物传感.8 改凝胶显示了在存在氟化物阴离子的情况下颜色的改变和凝胶－溶胶相转变,这可以为开发用肉眼的氟化物传感提供基础.
在本通讯中,我们设计了一种低分子的物质分子1,它由2-(2'-间苯二酚)苯并恶唑（HPB）
单元、尿素基团和长烷基链组成,能分别发挥像π-π互作用、氢键结合和范德瓦尔斯互作用的功能[图1(A)].如已经详细报道过的那样,HPB有两个互变异构体,它们通过受激态分子内质子转移（ESIPT）（参见ESI的方案2）具有烯醇（弱荧光）和酮（强荧光）形式两个发射最高值.9 在HPB中的分子内氢键结合可以因氟化物阴离子的存在而改变而不管其单体的形式或聚合物的形式如何,这表明了如以前报道过的可以看出的颜色变化.9,b,c 我们的兴趣集中在以下方面：（1）凝胶剂1在起源于HPB单元中分子内氢键结合的聚集态中采用平坦的构象,这可能在苯环的羟基质子和苯并恶唑基团的氮之间感生易化质子转移；（2）HPB中的羟基基团能够与氟化物阴离子选择性地互作用,这可能提供颜色的改变；（3）尿素分子部分能够与氟化物阴离子结合；因此,邻近尿素分子部分的分子间氢键结合在存在氟化物阴离子的情况下就会被瓦解,这就可能引起凝胶－溶胶转变.