The formation of alkali-metal ion complexes with the crown ethers, 18-crown-6(18c6), benzo-18c6 and dibenzo-18c6 has been investigated. Theoretical studies of structural changes on complexation, binding energies and changes in electron distribution have been carried out using ab initio quantum theoretical methods. A complementary study of the NMR chemical shifts and coupling constants has also ...

indandione 1 was brominated to yield 2-bromoindandione 2 which on further reacted with substituted thiocarbamides, carbamides, 2-aminothiophenols, 2-aminophenol and triazoles to furnished 3-substituted aniline-2-thia-4-aza-6,7-benzo-8-oxo-bicyclo [3.3.0]-1(5),3-octadiene 3, 3-substituted aniline-2-oxa-4-aza-6,7-benzo-8-oxo-bicyclo [3.3.0]-1(5),3-octadiene 4, 2-thia-5-aza-9-oxo-3,4-(3’-substitut...

Crown-ethers have recently been used to assemble porous liquids (PLs), which are liquids with permanent porosity formed by mixing bulky solvent molecules (e.g., 15-crown-5 ether) with solvent-inaccessible organic cages. PLs and crown-ethers belong to a novel class of materials, which can potentially be used for gas separation and storage, but their performance for this purpose needs to be asses...

A benzo[b]quinolizinium-benzo-15-crown-5 ether conjugate 2a is presented that enables the fluorimetric detection of Mg(2+) and DNA by a significant light-up effect, along with a change of the emission wavelength with different analytes (Mg(2+): 495 nm; DNA: 550 nm). The mechanism of the excited-state deactivation of 2a was investigated by steady-state fluorescence spectroscopy in media of varie...

The extraction-separation of lanthanum and europium ions with bis(2-ethylhexyl) phosphoric acid (DEHPA) in cyclohexane was improved by adding 12-crown-4 (12C4) to the aqueous phase as a masking agent. In the presence of this crown ether the extraction curve of lanthanum ions versus pH shifts to the higher pH region, while the curve is not influenced for the europium ions. Consequently the separ...

Two novel dithieno-benzo-imidazole-based compounds (M2 and A2) showed remarkable sensitivities towards Pb(2+) by 12-fold enhancement and 10-fold decay of fluorescence, respectively, in aqueous solutions. Substituent effects of different dithieno-benzo-imidazole-based moieties (M1, M2, A1 and A2) on the quantum yields, fluorescence lifetimes and sensitivities to Pb(2+) along with the reversibili...

Tetrahydro-1H-benzo[b]azonin-2,7-dione (2a) has been used as a precursor in the synthesis of dibenzo[b,f ][1,5]diazacyclododecene and dibenzo[b,g][1,6]diazacyclododecene ring systems 4 and 5, respectively, via periodate oxidation of the appropriate indolo-benzo[b]azonines 3 and 7. The synthesis of hexahydro-benzo[b][1,4]diazecin-2,7-dione (10) has been achieved by the Schmidt reaction of 2a. Th...

Treatment of P4 with in situ generated [Na][SnPh3] leads to the formation of the sodium monophosphide [Na][P(SnPh3)2] and the Zintl salt [Na]3[P7]. The former was isolated in 46% yield as the crystalline salt [Na(benzo-15-crown-5)][P(SnPh3)2] and used to prepare the homoleptic phosphine P(SnPh3)3, isolated in 67% yield, as well as the indium derivative (XL)2InP(SnPh3)2 (XL = S(CH2)2NMe2), isola...