The synthesis of four bis-macrocyclic conjugates made from the coupling of either diaza-15-crown-5 ethers (1 and 3) and diaza-18-crown-6 ethers (2 and 4) to either amide or carboxylate functionalized cyclen (1,4,7,10-tetraazacyclododecane), and their corresponding cationic Tb(III) complexes, Tb-1, Tb-2, and neutral complexes Tb-3 and Tb-4 are described. The effect on the ground, singlet excited...

Cohesive energy densities (C(w,MLA)/J cm(-3)) for ion-pair complexes (MLA: M(+) = Li(+) to Cs+; w: water) with six crown ethers (L), such as 18-crown-6 ether (18C6), benzo-18C6, and dibenzo-24-crown-8 one, and A(-) = picrate were calculated at 298 K by a procedure that uses either (i) an equation rearranged from that underlying log K(D,MLA)-vs.-log K(D,L) plots or (ii) intercepts of their plots...

A bolaamphiphilic low-molecular-weight gelator based on crown ether, which could self-assemble into organogels and hydrogels, was prepared. The contribution of each part of the structure to the gelation property was investigated by designing a series of analogues. A simple framework (crown ether-hydrophobic linkage-ammonium salt) was proposed.

After nitrogen, fluorine is probably the next most favorite hetero-atom for incorporation into small molecules in life science-oriented research. This review focuses on a particular fluorinated substituent, the trifluoromethoxy group, which is finding increased utility as a substituent in bioactives, but it is still perhaps the least well understood fluorine substituent in currency. The present...

The asymmetric unit of the title compound, C(8)H(12)N(+)·ClO(4) (-.)C(12)H(24)O(6), contains one half of the cationic [(C(2)H(5)-C(6)H(4)-NH(3))(18-crown-6)](+) moiety and one half of the ClO(4) (-) anion. Two O atoms of the crown ether, four C atoms and the N atom of the ethylanilinium unit and the Cl and two O atoms of the anion lie on a mirror plane. In the crystal structure, the -NH(3) (+) ...

A series of crown ethers, 12-crown-4, 15-crown-5, 18-crown-6, and dibenzo-30-crown-10, are examined as a possible means of shifting the mobilities of peptide ions. In this approach, a crown ether is added to a solution containing a mixture of peptides and is electrosprayed into the gas phase in order to create distributions of peptide-crown complexes. The ion complexes have different mobilities...

The synthesis and spectroscopic investigation of aza-crown ethers with anthraquinoneand 1-aminoanthraquinone-functionalized side chains are described. Cation-induced shifts in the UV/VIS absorption spectra of the ligands dissolved in propylene carbonate are observed only for Li+ among the alkali metal ions and for Mg2+ among the alkaline earth metal ions as well as for Ag+ and T1+. Only hypsoch...

The use of “fuel” compounds to drive chemical systems out equilibrium is currently interest because the potential for temporally controlled, responsive behavior. We have recently shown that transiently formed crown ethers exhibit counterintuitive templation effects when generated in presence alkali metal cations: “matched” cations, such as K+ with an 18-crown-6 analogue, suppress formation macr...