Lead(II) Complexes of Lateral Macrobicyclic Receptors That Incorporate a Crown Moiety and a Pyridine Head Unit
作者:David Esteban‐Gómez、Teresa Enríquez‐Pérez、Raquel Ferreirós‐Martínez、Marta Mato‐Iglesias、Carlos Platas‐Iglesias、Andrés de Blas、Teresa Rodríguez‐Blas
DOI:10.1002/ejic.201000642
日期:2010.11
titrations in 95 % methanol (I = 0.1 M, nBu 4 NClO 4 , 25 °C). The two receptors undergo two protonation processes in the pH range investigated (2.0 < pH < 12.0), which correspond to the protonation of the nitrogen atoms of the oxa-aza moiety. The log K PbL value obtained for L 7 [9.906(1)] is approximately 1.1 log K units higher than the one determined for L 8 [8.75(1)].
结合 1,10-diaza-[15]crown-5 (L 7 ) 或 4,13-diaza-[18]crown-6 (L 8) 的两个侧向大双环受体对铅 (II) 的配位特性) 片段被报告。在乙腈溶液中进行的分光光度滴定表明仅在溶液中形成了单核复合物。两种受体的 X 射线晶体结构表明,配体采用的构象是由涉及仲胺基团和关键氮原子的分子内氢键相互作用的存在所决定的。[Pb(L 7 )(NCS)](SCN)·0.5H 2 O的固态结构表明金属离子在大双环腔内不对称配位。Pb II 离子与吡啶单元的氮原子、两个仲胺原子配位,冠部分的两个氧原子和异硫氰酸酯基团的氮原子。Pb II 离子与两个关键氮原子以及冠部分的氧原子之一之间的距离太长(> 2.92 A)而不能被视为明确的键,而应仅被视为弱相互作用。L 7 和L 8 的质子化常数及其Pb II 复合物的稳定性常数通过在95 % 甲醇(I = 0.1
Protonated Macrobicyclic Hosts Containing Pyridine Head Units for Anion Recognition
作者:David Esteban‐Gómez、Carlos Platas‐Iglesias、Andrés de Blas、Luigi Fabbrizzi、Teresa Rodríguez‐Blas
DOI:10.1002/chem.200800092
日期:2008.6.27
trend observed for the recognition of halide anions by the macrobicycles presented herein as well as the sulfate-to-nitrate binding selectivity have been rationalised by means of DFT calculations at the B3LYP/LanL2DZ level. These studies indicate that the especially high binding selectivity for Cl(-) is the result of the optimum fit between the protonated macrobicyclic cavity and the size of the anion
“Cinderella” elements: Strategies to increase the stability of group 1 complexes by tailoring crown macrocycles
作者:Aurora Rodríguez-Rodríguez、Israel Carreira-Barral、David Esteban-Gómez、Carlos Platas-Iglesias、Andrés de Blas、Teresa Rodríguez-Blas
DOI:10.1016/j.ica.2013.11.022
日期:2014.6
Abstract The synthesis and structural characterization of six sodiumcomplexes with bibracchial lariatethers containing aniline or benzimidazole side arms, and derived from 1,7-diaza-12-crown-4, 1,10-diaza-15-crown-5 or 4,13-diaza-18-crown-6, are reported. The X-ray structures of four of these compounds have been obtained. Additionally, the X-ray structures of a sodium macrobicyclic complex derived from