Increased antenna effect of the lanthanide complexes by control of a number of terdentate N-donor pyridine ligands.

Three europium complexes with the terdentate N-donor ligand 2,6-bis(1H-pyrazol-3-yl)pyridine (L) have been synthesized, and their crystal structures have been determined. The ligand/metal ratios in these complexes are 3, 2, and 1. The photophysical properties of the complexes indicate more efficient ligand sensitization of europium emission for the homoleptic complex.

An easy assembled fluorescent sensor for dicarboxylates and acidic amino acids.

Two mesitylene based neutral receptors 1 and 2 bearing two thiourea binding sites were constructed as fluorescent probes for sensing dicarboxylates. Their binding affinities toward dicarboxylates, aspartate and glutamate have been investigated in acetonitrile solution by fluorescence titration experiments. Both fluorescent sensors exhibited some ability to discriminate the antipodal forms of aspartate and glutamate.

A highly selective on-off-on responsive lanthanide(iii) based probe for recognition of copper and hydrogen sulfide.

The development of a europium(iii) based probe (EuL1) for the detection of Cu(ii) ions and hydrogen sulphide is presented. With the addition of Cu(ii) ions, EuL1 displayed the greatest quenching among the other cations examined. The binding constant was 74,026 ± 2899 M(-1). Once combined with Cu(ii) ions, EuL1Cu demonstrated high specificity for hydrogen sulfide compared to other organic and inorganic sulfur compounds. EuL1Cu exhibited an on-off-on type luminescence change with the alternate addition of Cu(ii) ions and H2S along with reversible forming-separating of the complex.

Thermodynamic selectivity of functional agents on zeolite for sodium dodecyl sulfate sequestration.

This study proposes a thermodynamic approach to effectively select functional agents onto zeolite for sodium dodecyl sulfate (SDS) sequestration in greywater reuse. We combine isothermal titration calorimetry (ITC) and quantum chemistry simulation (QCS) to identify the interactions between SDS and agents at the molecular level. Three potential agents, cetyl trimethyl ammonium bromide (CTAB), N,N,N-trimethyltetradecan-1-aminium bromide (C14TAB), and 14-hydroxy-N,N,N-trimethyltetradecan-1-aminium bromide (C14HTAB), differ in carbon chain length and hydrophilic groups. The ITC titration of SDS with CTAB released the highest heat, followed by those with C14TAB and C14HTAB, as was the same trend for the amounts of SDS adsorbed by the respective functionalized-zeolites. Results suggest that the favorable SDS sorption occurred at the bilayer CTAB-zeolite is driven by enthalpy as similar as the SDS…CTAB interaction found, regardless of the contribution from electrostatic and/or hydrophobic behaviors, while the declined sorption is entropy-driven via the predominant hydrophobic interaction onto the monolayer CTAB-zeolite. The data presented here interpret the nature of molecularly thermodynamic quantities and enable the manipulation of sorption capacity optimization.

Responsive two-photon induced europium emission as fluorescent indicator for paralytic shellfish saxitoxin.

A water-soluble europium(III) complex (1) has been synthesized and demonstrated to be a specific fluorescence probe for the paralytic shellfish toxin saxitoxin, a neurotoxin that blocks the voltage-gated sodium channels on cell membranes. Saxitoxin binds to the europium complex (K(B) = 6.1 × 10(4) M(-1)) and triggers a two-photon induced f-f emission enhancement by over 100% and increases the two-photon absorption cross-section from 9 to 36 GM.