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...

An existing method was adapted to the purpose and validated in-house according to the IUPAC harmonised guideline for the determination of 15 EU priority polycyclic aromatic hydrocarbons (PAHs) in primary smoke condensates (PSCs) that are used to produce smoke flavourings for human consumption. Limits of detection (LOD) varied between 0.1 and 1.3 microg/kg, limits of quantitation (LOQ) between 0...

Plasticised poly(vinyl chloride)-based membranes containing the ionophores (α-, β- and γ-cyclodextrins (CD), dibenzo-18-crown-6 (DB18C6) and dibenzo-30-crown-10 (DB30C10) were evaluated for their potentiometric response towards promethazine (PM) in a flow injection analysis (FIA) set-up. Good responses were obtained when β- and γ-CDs, and DB30C10 were used. The performance characteristics were ...

The co-crystal, C7H9N4O2 (+)·ClO4 (-)·C20H24O6·3.25H2O, consists of theobrominium (3,7-di-methyl-2,6-dioxo-1H-purin-9-ium) cations, perchlorate anions and dibenzo-18-crown-6 and water mol-ecules. The crown ether is in a bent conformation, in which the planes of the aromatic rings subtend an angle of 63.7 (1)°. Inter-molecular O-H⋯O hydrogen bonding between the water mol-ecules and the O atoms o...

A conductance study of the interaction between Cs+, Rb+, NH4+, K+, T1+ and Ag+ ions and18-crown-6 (18C6), benzo-18-crown-6 (B18C6), dicyclohexyl-18-crown-6 (DC18C6),dicyclohexyl-24-crown-8 (DC24C8), dibenzo-24-crown-8 (DB24C8) in different binarymixtures of acetonitrile (AN) with dimethylsulfoxide (DMSO) and dimethylformamide (DMF)at 25 °C has been carried out. Formation constants of the result...

By employing different diimine complexes and a naphthanoimidazolate (L(1)) or benzoimidazolate (L(2)) anion ligand as linker, a series of trimetallo-macrocycles have been synthesized through a directed self-assembly approach that involves spontaneous deprotonation of the ligands in aqueous solution. Some compounds, namely, [M(3)L(3)](NO(3))(3) (M = (18-crown-6-phen)Pt, 1 or 7; (15-crown-5-phen)...

The mobility of coordinated methanol in the complex [Co(II)(Benzo[ 15]crown-5)(CH3OH)2] + was studied in nitromethane. The methanol exchange mechanism tends to an associative nature with an increasing amount of methanol in the solutions as can be deduced from the activation entropy. All activation data can be combined in an isokinetic relationship which is also valid for the respective complex ...

Reported here is an efficient recognition of K+ by 15-crown-5 functionalized gold nanoparticles in aqueous matrix containing physiologically important cations, such as Li+, Cs+, NH4+, Mg2+, Ca2+, and excess amount of Na+. Upon exposure to K+, the colloidal solution changes from red to blue, in response to surface plasmon absorption of dispersed and aggregated nanoparticles. The concentration ra...

Supramolecular cations formed by monoprotonated pyridazinium cations and cis-anti-cis-dicyclohexano[18]-crown-6 (DCH[18]-crown-6) or dibenzo[18]-crown-6 (DB[18]-crown-6) were introduced into [Ni(dmit)2]− salts (where dmit2− = 2-thione-1,3-dithiole-4,5-dithiolate). X-ray crystal structure analysis of (pyridazinium+)(DCH[18]-crown-6)[Ni(dmit)2]− (1) revealed a chair-type conformation of the DCH[1...