Supplementary information files for Impact of varying the phenylboronic acid position in macrocyclic Eu(iii) complexes on the recognition of adenosine monophosphate

Supplementary files for article Impact of varying the phenylboronic acid position in macrocyclic Eu(iii) complexes on the recognition of adenosine monophosphate The selective recognition of anions in water by artificial receptors remains a significant research challenge. The creation of a receptor selective for adenosine monophosphate (AMP) is particularly difficult due to its similarity in structure with the more negatively charged anions, ADP and ATP. We recently developed a macrocyclic Eu(III) complex that selectively binds AMP in water, by incorporating a sterically demanding quinoline arm that inhibits coordination of commonly interfering anions such as ATP. A phenylboronic acid motif was installed within the ligand to engage the ribose sugar of AMP through reversible covalent bonds. Herein we report two new Eu(III) complexes, [Eu·oBOH2]+ and [Eu·pBOH2]+, to investigate the impact of varying the position of the phenylboronic acid group on the anion binding properties of the Eu(III) receptors. We found that [Eu·pBOH2]+ showed preferential binding to AMP over ATP, but exhibits a lower level of discrimination between AMP and ADP compared with the isomeric complex [Eu·mBOH2]+. Surprisingly, [Eu·oBOH2]+ showed no response to anions but displayed a unique response to pH, ascribed to the direct coordination of the ortho-boronate ester to the Eu(III) centre. Finally, we present first principles computations that offer a promising approach to access the emission spectra of lanthanide complexes, aiding the design of responsive lanthanide probes with specific photophysical properties.

《大环铕(III)配合物中苯硼酸取代位置对一磷酸腺苷（adenosine monophosphate, AMP）识别性能的影响》一文补充材料。人工受体在水相中选择性识别阴离子仍是一项极具挑战性的研究课题。由于一磷酸腺苷（AMP）与电荷更高的阴离子二磷酸腺苷（ADP）、三磷酸腺苷（ATP）结构高度相似，开发对AMP具有选择性识别能力的受体尤为困难。本团队此前开发了一种大环铕(III)配合物，通过引入空间位阻较大的喹啉臂以阻断ATP等常见干扰阴离子的配位作用，从而在水相中选择性结合AMP；并在配体中引入苯硼酸基元，通过可逆共价键与AMP的核糖糖基结合。本文报道了两种新型铕(III)配合物[Eu·oBOH2]+和[Eu·pBOH2]+，用以探究苯硼酸基团的取代位置对铕(III)受体阴离子结合性能的影响。研究发现，[Eu·pBOH2]+相较于ATP对AMP表现出优先结合能力，但与同分异构体配合物[Eu·mBOH2]+相比，其对AMP与ADP的区分能力较弱。令人意外的是，[Eu·oBOH2]+对阴离子无响应，但展现出独特的pH响应性，这归因于邻位硼酸酯与铕(III)中心的直接配位作用。最后，本文展示了第一性原理计算方法，该方法可有效预测镧系配合物的发射光谱，有助于设计具有特定光物理性质的响应型镧系探针。