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The single-crystal X-ray structure of a microporous alkaline-earth phosphonate incorporating a new triphosphonate ligand is presented. [Sr.sub.2]([H.sub.2]L)([CH.sub.3]OH)[([H.sub.2]O).sub.4], where L = 1,3,5-tris(4-phosphonophenyl)benzene, crystallizes in triclinic space group P-1 (a = 6.9230(4) Å, b = 15.3370(9) Å, c = 16.1930(11) Å, α= 62.201(3)°, β= 85.288(4)°, γ = 86.665(4)°). The solid is sustained by cooperative interactions between both one-dimensional inorganic and organic columns and forms a two-fold interpenetrated microporous structure. Gas and vapour sorption experiments confirm the microporosity. Based upon the sustaining interactions, this compound can serve as a model for more porous structures as extension of its structure disfavours further interpenetration. Key words: metal--organic framework, coordination polymer, phosphonate, microporous, alkaline earth. Faisant appel a la diffraction des rayons X par un cristal unique, on a determine la structure cristalline d'un phosphonate de terre alcaline microporeuse incorporant un nouveau ligand triphosphonate. Le [Sr.sub.2]([H.sub.2]L) ([CH.sub.3]OH)[([H.sub.2]O).sub.4] dans lequel L = 1,3,5-tris(4-phosphonophenyl)benzene cristallise dans le groupe d'espece P-1 [a = 6,9230(4) Å, b = 15,3370(9) Å et c = 16,1930(11) Å, α = 62,201(3)°, β = 85,288(4)° et γ = 86,665(4)°. Le solide est soutenu par des interactions cooperatives entre les colonnes unidimensionnelles inorganiques et organiques et il forme une structure microporeuse binaire dans laquelle on observe une interpenetration. Des experiences de sorption de gaz et de vapeur confirment la microporosite. Sur la base des interactions de soutien, ce compose peut servir de modele pour des structures plus poreuses puisque l'extension de sa structure defavorise d'autre interpeneration. Mots-cles : squelette organometallique, polymere de coordination, phosphonate, microporeux, terre alcaline. [Traduit par la Redaction], Introduction With the illustration that network coordination compounds can sustain permanent pores (1) has come an interest in the design principles for such materials (2) and a concurrent upsurge in [...]

The coordination assemblies resulting from the complexation of 1,3,5-tri(4-sulfophenyl)benzene, [L.sup.3-], with copper(II) in the presence of pyridine are analyzed. The results have given insights into the subtleties of designing coordination polymers and open-channel solids and three different single crystalline solids are obtained from an initial crystallization.

A series of complexes of the type trans-[Co([(BA).sub.2]en)[(amine).sub.2]]Cl[O.sub.4]--where [(BA).sub.2]en is the bis(benzoylacetone)ethylenediimine dianion and the amines are morpholine (mrpln) 1, aniline (aniln) 2, benzylamine (bzlan) 3, piperidine (pprdn) 4, p-toluidine (p-toldn) 5, and pyrrolidine (prldn) 6--has been synthesized and characterized by elemental analysis, UV-vis, [sup.1]H NMR, and [sup.13]C NMR spectroscopy. The crystal and molecular structure of trans-[Co([(BA).sub.2]en)[(mrpln).sub.2]Cl[O.sub.4] (1) has been determined by X-ray crystallography. The electrochemical reduction of these complexes at a glassy-carbon electrode, in the potential range of 0.5 to -2.0 V (vs. Ag/AgCl), in acetonitrile solution, indicates that the first reduction potential of Co(III/II) is irreversible, which is accompanied by the dissociation of the axial amine-cobalt bonds. This potential is dependent on the p[K.sub.a] of the axial amines. The second reduction potential of Co(II/I) shows reversible behavior and is also independent of the axial amine p[K.sub.a]. These results indicate the loss of the axial amines in the first redox process and the involvement of a four-coordinate species in the second redox step. Key words: Schiff base, cobalt(III), axial amine, electrochemical properties, crystal structure.

The use of second-harmonic generation at different wavelengths to compare the resonant contributions of two simple dipolar chromophores, nitroaniline and nitrosulfenamide is reported. The result shows that pi intermolecular interaction does result in excitations that are observable in the linear spectrum of nitroaniline and thus could have an influence on the nonlinear response.

Organochalcogen-nitrogen heterocycles such as the 1,2,5-chalcogenadiazoles have a distinct tendency to establish intermolecular links in the solid state through secondary bonding interactions E...N (E=S, Se, Te). Because of its more polar character and lower-lying antibonding orbitals, the tellerium derivatives possess the strongest association energies.

Research has been conducted on lithium sulfenamides. The preparation of these compounds with alkyllithium is desribed.