Louis Cazaux

Mono(di)nuclear Europium(III) Complexes of Macrobi(tri)cyclic Cryptands Derived from Diazatetralactams as Luminophores in Aqueous Solution

To increase the excellent light-emitting properties of the Eu3+ ion, macrobicyclic and macrotricyclic ligands 7 – 10, incorporating a 18-membered tetralactam ring (acting as a lanthanide binding site) and a sensitizer group (2,2′-bipyridine or 2,2′-bipyridine 1,1′-dioxide moiety), were synthesized. The mononuclear and dinuclear europium cryptates derived from these ligands were isolated and characterized. Their luminescent properties and those of the corresponding cryptates containing a phenanthroline group (see 11 and 12) were examined in H2O and D2O solutions at 77 and 300 K. It results that the tetralactam moiety plays a major role in the efficient shielding of the complexed Eu3+ ion from the water environment. The cryptands incorporating the bipyridine unit are the most promising labels according to their photophysical properties (excitation maxima, emission decay lifetime, relative luminescent yield). In contrast with literature data, introduction of N-oxide groups in the bipyridine chromophore weakens the luminescence properties of the cryptate.

Macrocyclic polyether tetralactams II : a study of their binding properties with alkaline - earth cations

Abstract Solvent extractions of alkali and alkaline-earth picrates were carried out in a waterchloroform system using newly synthesized tetralactams containing dimethyleneoxy moieties. These ligands display excellent extracting properties for Ca 2+ , Ba 2+ , and Sr 2+ cations. Some of the less lipophilic derivatives have greater preference for Ba 2+ vs. Na + and Zn 2+ and, to a lesser extent, K + , Mg 2+ and Ca 2+ . In addition, the stability constants were determined for the 1:1 and 1:2 M 2+ :tetralactam complexes by UV spectrophotometry in THF solution. In each series of tetralactams log K S values as high as 6 were observed for Ca 2+ , Sr 2+ and Ba 2+ ions. The 18-, 21- and 24- membered tetralactams complex preferentially Sr 2+ , Ca 2+ and Ba 2+ cations respectively.

Styrylbenzodiazinones 3. Chromo- and fluoroionophores derived from monoaza-15-crown-5. Photophysical and complexing properties

Abstract The photophysical and complexing properties of two chromo- and fluoroionophores derived from the monoaza-15-crown-5 and styrylbenzodiazinones are studied by UV spectrophotometry and spectrofluorometry. Their comparison with those of BOZ-crown and DCM-crown analogous dyes shows the specificity of the benzodiazinone moiety on these properties. The occurrence of twisted intramolecular charge transfer states by internal rotation around the ArCN bond and the effects of biological metallic ions are discussed.

Macrocyclic polyether tetralactams I : synthesis and cyclization studies

Abstract A three-step method for the synthesis of new 18, 21 or 24-membered macrocyclic tetralactams with two dimethyleneoxy moieties is described. The method consists in the ring closure of a bis-secondary amine with a diamide diacid activated by the thiazolidine-2-thione group. The cyclization does not require high dilution techniques and provides the expected tetralactams in good yields, ranging from 42% to 73%. This synthetic pathway leads to dissymmetrical or symmetrical molecules with substituents of variable lipophilicity.

Synthesis of macrocyclic polyhydroxy tetralactams derived from L-tartaric acid and β-hydroxyglutaric acid

Abstract The synthesis of new 16-, 18-, 19- or 20-membered secondary tetralactams with L-tartaric acid or β-hydroxyglutaric acid moieties is investigated. The stepwise synthesis with an intermediate diamide diamine provides overall good yields (30–55%) compared with other processes using an intermediate diamide diacid or direct macrocyclization. This synthetic pathway leads to symmetrical or unsymmetrical polyhydroxytetralactams with variable hydroxyl group number. Use of mild acylating agents in this approach allows to avoid the protection-deprotection steps of hydroxyl groups.

Macrobicyclic and macrotricyclic tetralactams with 1,10-phenanthroline units. Dinuclear Eu3+ cryptate of the macrotricyclic ligand

Abstract The synthesis of a key 18-membered diazatetralactam and of subsequent macrobicycle and macrotricycle with 1,10-phenanthroline units is described. The predominant macrotricyclic cryptand gives a dinuclear europium cryptate characterized by MS techniques and luminescence emission.

A barium selective macrocyclic tetralactam with dimethyleneoxy moieties

Abstract Two new 18-membered tetralactams with two dimethyleneoxy moieties are synthesized by direct macrocyclization or steps reaction. In the latter case symmetrical or unsymmetrical compounds can be obtained. The unsymmetrical tetralactam shows a very high selectivity for barium vs. Na + and Zn 2+ and to a lesser extent vs. K + , Mg 2+ and Ca 2+ in the extraction procedure with picrates. In addition, the stability constants are determined for the two 1:1 tetralactam:Ba 2+ complexes by UV spectrophotometry in THF solution.

New podands and macrocycles containing “dioxazaphosphocane” moieties. Synthesis, structural determination and study of their binding and ionophoric properties with Ca2+ and Mg2+ cations

Abstract The reactions of diacids with the bicyclophosphane 1 lead to podands 3a-f in which two dioxazaphosphocane moieties are linked by a more or less rigid spacer owing to the starting diacid. Macrocycles 4a-b are obtained by cyclization of podands 3a-b by way of Michaelis-Becker reaction. The formation of Ca 2+ and Mg 2+ complexes with 3a-f and 4a-b has been investigated by UV, IR and NMR spectroscopies. Liquid-liquid extraction studies show for macrocycles efficient extracting properties and good selectivities of Ca 2+ towards Mg 2+ . The calcium transport across a chloroformic membrane agrees better with stability constants than with extraction data.

Le vibrateur SO dans les oxo-2 dioxathiannes-1,3,2: dédoublement de bandes par résonance de Fermi et utilisation possible en analyse conformationnelle

Abstract Forty-seven alkyl-, chloro- or nitro- cyclic sulfites in anancomeric conformation are examined in different solvents and, some at variable temperature through the SO region. Most of them show a doublet SO adsorption assigned to Fermi resonance by the method of solvent variation; this splitting does not arise from the intramolecular association only detected in less substituted molecules with non polar solvents. νSO frequencies are thus deduced and classified in three well localized types according to the three possible orientations of the SO group on a six membered cycle. Bellamy diagrams from eleven compounds indicate that the solvent effect on these frequencies is largely structure dependent. Finally, the integrated molar absorption coefficient of the νSO bands is found nearly constant and independent of the SO orientation.

Un tetralactame macrocyclique dérivé de l'acide dioxa-3,6 octanedioique, nouvel ionophore neutre sélectif du calcium

Abstract A new 24-membered tetralactam with two ethylene dioxy moieties and a mirror symmetry is prepared. Its binding abilities for Na + , Ca 2+ , Mg 2+ and Zn 2+ ions was determined by an extraction procedure. A good affinity and a high selectivity are observed for Ca 2+ . The stability constant of the tetralactam:Ca 2+ 1:1 complex is estimated by UV spectrophotometry in THF solution.