Structural studies and binding properties of pendant diazacoronands—precursors to macrocyclic compounds of planar chirality
摘要:
Structural studies of pendant diazacoronands having an N-benzoyl, N-acetyl, O-benzyl or O-benzoyl side arm were performed by means of X-ray and temperature-dependent H-1 NMR experiments. The energies of macroring flipping process were determined for three pendant diazacoronands. The complexation properties of pendant diazacoronands toward the alkali metal cations (Na+, K, and Rb+) were estimated by ESI-MS experiments. (c) 2006 Elsevier Ltd. All rights reserved.
Manganese Complex of a Rigidified 15-Membered Macrocycle: A Comprehensive Study
作者:Kristof Pota、Enikő Molnár、Ferenc Krisztián Kálmán、David M. Freire、Gyula Tircsó、Kayla N. Green
DOI:10.1021/acs.inorgchem.0c01053
日期:2020.8.17
devoted to find an appropriate ligand for Mn(II) ion encapsulation by providing balance between the seemingly contradictory requirements (i.e., thermodynamic stability and kinetic inertness vs low ligand denticity enabling water molecule(s) to be coordinated in its metal center). Among these ligands, a large number of pyridine or pyridol based open-chain and macrocyclic chelators have been investigated
由于锰 (II) 配合物在磁共振成像 (MRI) 领域中的重要性日益增加,通过提供看似矛盾的要求之间的平衡(即,热力学稳定性和动力学惰性与低配体齿数的关系,使水分子能够在其金属中心配位)。在这些配体中,迄今为止已经研究了大量基于吡啶或吡啶醇的开链和大环螯合剂。作为开发这些螯合剂的下一步,使用既定方法合成并表征了15-pyN 3 O 2 Ph 及其过渡金属配合物。15-pyN 3 O 2Ph 配体结合了吡啶和邻亚苯基单元以降低配体的灵活性。热力学性质、质子化和稳定性常数是使用 pH 电位测定法确定的;通过单晶X射线衍射法获得了游离配体及其锰配合物的两种质子化状态的固态结构。结果显示在第一个配位球中具有两个水分子的七配位金属中心。发现 [Mn(15-pyN 3 O 2 Ph)] 2+的纵向弛豫率为 5.16 mM –1 s –1在 0.49 T (298 K)。此外,11.72 mM –1 s
Exploration of structural motifs influencing solid-state conformation and packing of unclosed cryptands sharing the same 19-membered macrocyclic core
amide protons, UCs adopted only three well-defined geometries in all 10 analyzed crystals. This structural resemblance between conformations of UCs, however, is not translated into similarities in terms of intermolecular interactions and crystal packing. This contradicting intra- and intermolecular solid-state behavior is likely connected with an ability of these macrocyclic compounds to engage in
depends on the number of ferrocene centers and amide groups in the receptor, and on the accessibility of the binding sites. Clear two-wave cyclic voltammetry features allowed the amperometric titration of H2PO4− and ATP2− by ligands L4 and L5 built from a cyclotriveratrylene structural unit, and containing a combination of three ferrocene centers with three (L4) or six (L5) amide groups.
新含酰胺的二茂铁基配体,大号1 - 5,制备和伏安和1个阴离子的1 H NMR调查结合物在有机介质中进行。的电化学识别能力大号1 - 5朝˚F -,HSO 4 -,H 2 PO 4 -和ATP 2-“氢键”是基于阴离子络合到还原的中性配体的氢键与酰胺质子之间的协同作用以及配体的氧化阳离子形式形成的离子对相互作用。阴离子-配体相互作用的强度取决于受体中二茂铁中心和酰胺基团的数量,以及结合位点的可及性。澄清的两波循环伏安法的特征允许H的电流滴定2 PO 4 -和ATP 2-通过配体大号4和大号5从cyclotriveratrylene结构单元建成,和含有三种二茂铁中心具有三个(组合大号4)或六(L5)酰胺基。
Nikonowicz; Grzegorzewski; Palys, Polish Journal of Chemistry, 2004, vol. 78, # 9, p. 1785 - 1793
作者:Nikonowicz、Grzegorzewski、Palys、Jurczak
DOI:——
日期:——
A new method for the synthesis of diazacoronands via double-amidation reaction
Alpha,omega-diamino aliphatic ethers react under ambient conditions with dimethyl alpha,omega-dicarboxylates, in methanol as a solvent, to give the cyclic diamides in good yields. Their subsequent reduction with a borhoydride-dimethyl sulphide complex affords the respective diazacoronands.