The title complexes displayed a marked dependence of their luminescence properties upon pyridine substitution. The ligand with the 4-carbamoyl-substituted pyridine showed a long-lived luminescence of near-unity quantum yield for Tb3- and quite reasonable values for Eu3+, Sm3+ and Dy3-, thus making it an excellent candidate for a luminescent probe to be attached to biomolecules by a peptide-like linkage.

The synthesis of novel Tb"' labels suitable for protein labelling are reported. Their luminescence properties as antibody conjugates were measured and compared to the results of corresponding Tb"' chelates of the parent ligand structures. When the lowest triplet-state energy level of the parent donor ligand was over 23 000 cm-I, i. e., the energy gap between the 5D, level of Tb"' and the lowest triplet-state energy level of the ligand exceeded 2600cm-', the label derivative with a long decay time (~=1.35-2.93 ms) and a high luminescence yield (E . 0 = 3 770-4 560) was found to be suitable for bioaffinity assays.Introduction. -Long-lifetime emitting lanthanide chelates as sensitive labels or probes, and time-resolved fluorometry in detection have already been used in a number of applications in bioaffinity assays [l].In commercial systems, due to the many requirements of optimal lanthanide chelate labels, compromises have been made, e.g., the detection comprises two separate steps, as a direct measurement of the analyte without any enhancement step is impossible [2]. In this respect, these technologies are not suitable for all applications, such as in situ hybridization, immunohistochemistry, homogeneous assays, and fluorescence imaging. In addition to sensitive bioaffinity assays, new highly luminescent and stable lanthanide labels permit the development of multilabel, miniaturized assay devices with simplified protocols and thus make it possible to perform multiparametric assays on sub-microliter volumes of samples. A lot of research effort has been directed to the design and synthesis of optimal labels also suitable for the applications mentioned above. The chelating agents commonly used for the sensitization of Eu"' and Tb"' ion luminescence include P-diketones

The hydrophilic oxygen atoms of polyethylenoxide chains inserted as pillars in gamma-zirconium phosphate form hydrogen bonds with the acid groups of the host. As a result the pillars are almost perpendicular to the gamma layers. Upon changing the pH level of the supernatant solution the hydrogen bonds are broken and the pillars become almost perpendicular to the layers (shown schematically). Thus there is a reversible enlargement-shortening of the interlayer space.

Confinement may efficiently condition the stereochemical outcome of a reaction through space constriction and molecular close contact. This article briefly reviews recent approaches of supramolecular chemistry to achieve chiral confinement. Crystallization is not always possible and the use of chiral crystals or clathrates lacks generality. The construction of solid supramolecular assemblies circumvents some of the problems of the crystal chemistry. In this regard, molecular imprinting of polymeric matrices with orifices mimicking the transition state of an enantioselective process is a very young, promising technique. Zeolites provide porous, rigid environments to host molecules without the need of lucky crystallizations, yet zeolites are not chiral per se and must be chirally modified. Besides, the limited dimension of their pores restricts the size of the guest molecules. Despite these problems, useful asymmetric photochemical reactions have been performed on zeolites. Finally, the formation of pillared lamellar structures, from inorganic salts of tetravalent transition metals covalently grafted with organic chains, is considered. The adequate selection of functionality and chirality of the organic pillars would afford custom-made, highly porous, 3D hybrid organo-inorganic scaffolds. However, the production of asymmetric processes within these layered materials still remains to be seen.

The topotactic exchange reactions of y-zirconium phosphate and y-zirconium phosphate/methylphosphonate with phosphonic acids derived from azacrown ethers of different sizes was examined. Prior intercalation of hexylamine was necessary in most cases to attain the maximum exchange level predicted by molecular modeling. Materials with imbricated or nonimbricated layers were obtained depending on crown size and exchange level. Exchange of methylphosphonates in y-zirconium phosphate/methylphosphonate was only observed when hexylamine had previously been intercalated. The exchange with the bisphosphonic acid derived from l,lO-diaza[l8]-crown-6 gave a material with an interlayer

The synthesis of three novel pyrazole-containing complexing acids, N,N,N',N'-{ 2,6-bis[3-(aminomethyl)pyrdzol-l-yl]-4-methoxypyridine}tetrakis(acetic acid) (l), N,N,N',N'-{2,6-bis[3-(aininomethyl)pyrdzoI-1-yl]pyrazine}-tetrakis(acetic acid) (2), and N,N,N',N'-{6,6'-bis[3-(aminomethyl)pyrazol-l-yl]-2,2-bipyridine)tetrakis(acetic acid) (3) is described. Ligands 1-3 formed stable complexes with Eu"', Tb"', Sm"', and Dy"' in H 2 0 whose relative luminescence yields, triplet-state energies, and emission decay lifetimes were measured. The number of H 2 0 molecules in the first coordination sphere of the lanthanide ion were also determined. Comparison of data from the Eu"' and Tb"' complexes of 1-3 and those of the parent trisheterocycle N,N,N',N'-{2,6-bis[3-(aminomethyl)pyrazol-1-yl]pyridine}tetrakis(acetic acid) showed that the modification of the pyridine ring for pyrazine or 2.2'-bipyridine strongly modify the luminescence properties of the complexes. Me0 Substitution at C(4) of 1 maintain the excellent properties described for the parent compound and give an additional functional group that will serve for attaching the label to biomolecules in bioaffinity applications.Introduction. -Immunological analyses based on luminescent labels and time-resolved fluorescence (TRFIA) are becoming highly competitive [ 11 compared to radioimmunoassays which present severe drawbacks mainly related to the radioactivity of the labels (expensive analysis, high risks for the analyzer, environmental problems, restrictive protocols for radioactive waste disposal, difficulties in obtaining legal handling licenses, etc. ). In contrast, fluorimetric labeling with lanthanide complexes is comparatively inexpensive, not dangerous, and fluorescence can be quickly measured using automated and relatively simple equipment.Present TRFIA labeling involves the attachment to the biomolecule of an organic moiety to which lanthanide ions are chelated but in a nonfluorescent form, followed by a development procedure in which the lanthanide ions are extracted into a so-called enhancer solution where the lanthanide forms a new chelate which is luminescent [2]. These manipulations limit sensitivity and avoid following the bioaffinity reaction in situ. For instance, this labeling technique cannot be utilized for the localized quantification of specific nucleic-acid sequences in individual cells by microscopy or flow cytometry, because the localization information is lost in the development step. The localized information is, thus, essential for the detection of, e g . , small fractions of cancer or other rare cells in patient samples.Therefore, TRFIA would highly increase its sensitivity and applicability if a second generation of lanthanide labels, luminescent on themselves, could be used, for which the aforementioned development step would be no longer necessary.

Having a gas: Topotactic exchange (65 %) of γ‐zirconium phosphate with terphenyldiphosphonic acid yielded a pillared material with a specific area of 90 m2 g−1. Subsequent treatment with hypophosphorous acid afforded a material of α type, with no incorporated hypophosphite and a specific area of 400 m2 g−1, which took up 74 cm3g−1 of H2 at 650 Torr and 77 K.

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