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...

Introduction: This study was designed to observe the success of three quarter crown over conventional full veneer crown in the posterior teeth (premolars and molars) where there has been considerable destruction of tooth structure but with the buccal surface remaining intact. Method: A total number of 30 patients were studied. Among which 15 patients were treated with three quarter crown and re...

Reaction of the deprotonated N-thiophosphorylated thiourea (4'-benzo-15-crown-5)NHC(S)NHP(S)(OiPr)(2) (HL) with NiCl(2) in aqueous EtOH leads to dark green [Ni(L-1,5-S,S')(2)]·2H(2)O crystals that were isolated by recrystallization from a mixture of CH(2)Cl(2) and n-hexane.

The sensing response of 15-crown-5-ether functionalized polythiophene to Li+, Na+, and K+ has been investigated at the atomistic level using molecular dynamics simulations. The stability associated with all the identified binding sites has been corroborated by quantum mechanical calculations. Although the cavity of the macrocycle is not the most visited binding site, such receptor is responsibl...

15-Crown-5-appended metalloporphyrin causes a K(+)-driven self-organization to bind a bifunctional guest ditopically, thereby allowing the circular dichroism (CD) detection of chirality induced in the ensemble when chiral amines are employed as the guest; the chiroptical properties are discussed.

Crown ethers 12-crown-4 (12C4), benzo-15-crown-5 (B15C5), 18-crown-6 (18C6), nitrobenzo-18-crown-6 (NB18C6) dibenzo-18-crown-6 (DB18C6) and dicyclohexyl-18-crown-6 (DC18C6), dissolved in dichloromethane, are able to form oxonium-ion complexes in contact with aqueous sulfuric and hydrochloric acid solutions. This ability allows the transfer of Cr(VI) oxanions from the acid media, through an ...

In a three-component system containing dibenzo-24-crown-8 (1), diamino-dibenzo-24-crown-8 (2), and 1,2-bis(4,4(')-dipyridyl)ethane (3(2+)), axle 3(2+) can shuttle between wheels 1 and 2 by acid-base control, accompanying color changes from yellow to red. This system could not only be taken as a chromophoric supramolecular switch, but also exhibit a function as INHIBIT logic gate.