Selective Cu(ii) sensing by a versatile AIE cyanostilbene-based gel system

Cyanostilbene-based derivatives 1-3 were designed, synthesized and fully characterized. By screening their gelating abilities, we observed that the subtle difference in the position of the pyridine nitrogen greatly affected the resulting fluorescence and gelation properties. Notably, 1 was found to be a versatile ambidextrous gelator capable of forming organo-, hydro-, and Cu(ii) specific metallogels. Furthermore, a rare organogel-to-metallogel transformation at room temperature was also observed upon exposure of the 1-DMSO/H2O gel to aqueous Cu(ii). This process, accompanied by colour and fluorescence changes, provides an effective strategy for the preparation of novel sensing soft materials

Preparation of amino acid anthraquinone oxalamide derivatives as colorimetric sensors for detection of the fluoride anion in solution and gel.

The invention relates to oxalamide derivs. of anthraquinone with general formula I [R1 is C1-6 alkyl, Ph, benzyl, or p-hydroxybenzyl; R2 is H, C1-6 alkyl, benzyl, or M+; X = (CH2)1-9] and their optical isomers and their mixts., including their prepn. and use for binding fluoride anions in soln. and gel, causing a change in color of the soln. and change in color and morphol. of the gel (phase change from gel to liq.). Thus, I (R1 is L-leucine side chain; R2 is Me; X is CH2) was prepd. by reactions of oxalyl chloride, L-leucine Me ester hydrochloride, N-benzylethylendiamine, and ethyl-N-1-anthraquinone oxamate and shown to bind fluoride anion, but not chloride, bromide, or iodide anions

Photophysical characterization and the self-assembly properties of mono- and bis-pyrene derivatives for cell imaging applications

A series of fluorescent mono-(1-4) and bis-pyrene derivatives (5-7) were synthesized and their photo-physical and self-aggregation properties in solution were fully investigated by UV-vis and fluorescence spectroscopies and dynamic light scattering (DLS). While in dilute DMSO mono-pyrene derivatives 1-4 show the characteristic features of monomer emission, bis-pyrene derivatives 5-7 display both monomer and excimer emissions, the latter attributable to a dynamic process. The gelation behaviour of these compounds was also studied, and only mono-pyrene leucine derivative 1 was found to display efficient gelation in aromatic solvents, such as toluene and p-xylene, and in a polar solvent mixture, water/DMSO (4 : 1 v/v). Finally, mono-pyrenes 1-4 showed no apparent cytotoxic impact on A549 and RD cell lines; derivatives 1-5 showed accumulation within both live and fixed cells, and macropinocytosis was found to be the main pathway for 5 to enter into the cells

Reversible luminescent gels containing metal complexes

Gelators are compounds capable of solidifying various solvents and water. Organic gels, and in particular hydrogels, are interesting soft materials with many potential applications. In this paper the formation of luminescent gels in water and dimethyl-formamide as solvents is reported. The gels are prepared by using a carboxylate-based aliphatic gelator (1) and a N,N\u2032-bis(O-methyl- lyrOH) oxalamide derivative (2). The gels are transparent, and form fiberlike structures in the presence of the red luminescent moiety, a EuIII hemicaged complex. The spectroscopic behavior of the complex is investigated in different solvents and when is entrapped in the gel. In order to probe the involvement of the chemical structure of the luminescent moiety in the gel network, a ruthenium complex, Ru(bpy)2(dppz)2+ (where bpy = 2,2\u2032-bipyridine and dppz = dipyrido[3,2-a:2\u2032,3\u2032-c]phenazine) has also been employed. The complex is in fact nonluminescent in water, while emitting when incorporated in the gel. Such "switching on" behavior is attributed to the incorporation of the complex into the lipophilic environment of gel fibers, where it is shielded from quenching by water molecules