Thermodynamic Analysis of Receptors Based on Guanidinium/Boronic Acid Groups for the Complexation of Carboxylates,α-Hydroxycarboxylates, and Diols: Driving Force for Binding and Cooperativity
作者:Sheryl L. Wiskur、John J. Lavigne、Axel Metzger、Suzanne L. Tobey、Vincent Lynch、Eric V. Anslyn
DOI:10.1002/chem.200305737
日期:2004.8.6
thermodynamics of guanidinium and boronicacidinteractions with carboxylates, alpha-hydroxycarboxylates, and diols were studied by determination of the binding constants of a variety of different guests to four different hosts (7-10). Each host contains a different combination of guanidinium groups and boronicacids. The guests included molecules with carboxylate and/or diol moieties, such as citrate, tartrate
A Fluorescent Sensor for 2,3-Bisphosphoglycerate Using a Europium Tetra-N-oxide Bis-bipyridine Complex for Both Binding and Signaling Purposes
作者:Michael D. Best、Eric V. Anslyn
DOI:10.1002/chem.200390003
日期:2003.1.3
synthesized as a fluorescentsensor for 2,3-bisphosphoglycerate (BPG, 3). The design features a tris-functionalized triethylbenzene core to preorganize binding groups. The three cationic moieties, a tetra-N-oxide bipyridine-europium complex and two ammonium groups, were included to complement the three anionic functionalities on the guest. Beyond acting as a binding site, the europiumcomplex was used to signal
设计并合成了宿主1,作为2,3-双磷酸甘油酸酯(BPG,3)的荧光传感器。该设计具有三官能化的三乙苯核心,可预组织结合基团。包括三个阳离子部分,四-N-氧化物联吡啶-complex络合物和两个铵基,以补充客体上的三个阴离子官能团。除了充当结合位点之外,the配合物还用于通过改变电荷转移发射来指示客体的结合。通过监测客体添加后荧光信号的减少,在50%甲醇/乙腈中测定1:1与BPG的配合物,其K(a)为6.7 x 10(5)mol(-1)。在滴定相关的糖酵解中间产物的过程中,缺少第二磷酸酯(4-6)进入宿主1,观察到2:1宿主与客体的结合。相似地,缺少铵基的对照化合物2以2∶1的方式结合BPG和4-6。而且,磷酸苯酯7以1:1的化学计量比与宿主1结合,其K(a)小于3的三倍。
Large pKa Shifts of ?-Carbon Acids Induced by Copper(II) Complexes
作者:Zhenlin Zhong、Brenda J. Postnikova、Robert E. Hanes、Vincent M. Lynch、Eric V. Anslyn
DOI:10.1002/chem.200400396
日期:2005.4.8
A series of synthetic receptors (4-6) incorporating metal ions, specifically copper(II), were examined for their ability to enhance the acidity of active methylene compounds. The copper(II) complexes were observed to reduce the pKa of 1,3-diketone carbon acids in acetonitrile by as much as 12 pKa units. The relatively large pKa reduction achieved by the complex is attributed to the electrostatic interaction