In this report, we reasoned that non-covalent modification of amyloid beta (Aβ) by crown ethers could inhibit its aggregation. We demonstrated that PiB-C, a conjugate PiB and crown ether, could significantly reduce the aggregation in vitro. Additionally, two-photon imaging showed that PiB-C could efficiently label Aβ plaques and CAAs in AD mice.

Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2) and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4). In these alkali metal complexes, not all crown ether O atoms participate in the coordination, which depicts the coordination ability of the C-, Si/C-, and Si-bonded O atoms. Furthermore, the inverse case—the coordination of the larg...

Programming the sequence of functional units in redox-switchable hetero[3]rotaxanes is achieved by integrative self-sorting for a library five crown ethers.

The reaction of Pb[BF(4)](2) in H(2)O/MeCN solution with the macrocycle 18-crown-6 gave the dinuclear complex [{Pb(18-crown-6)(H(2)O)(μ(2)-BF(4))}(2)][BF(4)](2), containing two nine-coordinate lead centres, each bound to all six oxygens of a crown ligand, one water molecule and bridged by two μ(2)-BF(4) groups. In contrast, the oxa-thia crown [18]aneO(4)S(2) gave the mononuclear [Pb([18]aneO(4)...

The interaction between hydronium ion and several crown ethers was studied via conductometry in nitromethane at 25 °C and 1H-NMR techniques. The stabilities of the resulting 1:1 complexes were determined from the conductance data and found to vary in the order DC18C6 > 18C6 > DB30C10 > DB24C8 > DB18C6 > ~B15C5 > DB21C7. For the first time, evidences for the formation of a 2:1 san...

Liquid-liquid extractive-spectrophotometric studies of sodium ion complexes of 18crown-6(18C6), dibenzo-18-crown-6(DB18C6), 15-crown-5(15C5), and 12-crown-4(12C4) and anionic dyes [4-(2-pyridylazo)-resorcinol monosodium salt monohydrate (PAR), Eriochrom Black T (EBT), and methyl orange (MOR)] and sodium picrate (PICRAT) as the counter ion are described. The overall extraction equilibrium consta...

Driven by orthogonal pillar[5]arene-based and crown ether-based molecular recognitions, a dynamic [1]catenane with pH-responsiveness was constructed via threading-followed-by-complexation.

Photochemistry, Fluorescence, Crown Ethers, Biology The complexing of thallous ions (T1+), with the crown ether dibenzo 18 crown-6 polyether (DB) has been studied by NMR, fluorescence, and pulse radiolysis techniques. NMR data show a strong interaction of the T1+ ions with the aromatic moieties. This is also illustrated by a static quenching of the aromatic fluorescence by Tl+. The rates of rea...

The ability of crown ethers [1—4] and cryptands [5—7] to selectively complex ions and neutral molecules has been the subject of extensive studies over the past two decades. One of the most impor­ tant problems under investigation was the transport of ionic species through membranes in biological sys­ tems [8 ]. Of several transport mechanisms proposed and demonstrated in natural and artificial ...