Triboluminescence and crystal structures of non-ionic europium complexes

The triboluminescence of three non-ionic europium complexes, Eu(TTA)(3). bipy (1), Eu(TTA)(3). dia (2) and Eu(DBM)(3). dmbp . H2O (3) (TTA=2-thenoyltrifluoroacetonate, DBM=dibenzoylmethanate, bipy=2,2'-bipyridine, dia=4,5-diazafluoren-9-one, dmbp=4,4'-dimethyl-2,2'-bipyridinate), was observed. Structure determinations of 1 and 3 were carried out. The triboluminescence maxima of 1 and 2 are similar to those of their photoluminescence. The disorder of the thienyl ring and CF3 groups in 1 and the disorder of water in the packing of 3 may be responsible for their triboluminescent activity

X-Ray and spectroscopic re-investigation of urotropine-p-nitrophenol complex

The product of the reaction between urotropine and p-nitrophenol, reported as a 1:1 adduct that belongs to the triclinic P 1 space group, is, in fact, a 1:2 [C6H12N4]. (p-HOC6H4NO2](2). [H2O] hydrate that crystallizes in the monoclinic C2 space group. In the crystal structure, one nitrogen atom of the urotropine moiety is linked by a hydrogen bond to the hydroxyl group of a p-nitrophenol molecule [N . . .O = 2.655 (7) Angstrom]; the [C6H12N4]. [p-HOC6H4NO2] entities are linked into a linear one-dimensional chain through the lattice water molecule [O . . .N = 2.871 (8), O . . .O = 2.878 (7) Angstrom]. The other p-nitrophenol moiety is disordered over two positions across the two-fold axis; its interaction with adjacent water molecules [O . . .O = 2.53 (1), 2.57 (2) Angstrom] holds neighboring chains together. The FTIR spectrum of the complex in the solid indicate the formation of OH . . .N intermolecular hydrogen bond described by an asymmetric double minimum potential and weak Zundel's polarizability. The spectroscopic measurements in solution demonstrate the dissociation of the complex observed in the solid and prove the presence of the 1:1 complexes urotropine-p-nitrophenol. In these complexes no proton transfer from p-nitrophenol to urotropine is observed. (C) 2001 Elsevier Science B.V. All rights reserved

Aminoguanidinium (ethylenediamine-N,N,N ',N '-tetraacetato)antimonate(III) monohydrate

In the title complex, (CH7N4)[Sb(C10H12N2O8)]. H2O, the lone-pair electrons of the Sb atom occupy an axial site in the psi-pentagonal bipyramidal polyhedron [Sb-N 2.265 (2)-2.507 (2) and Sb-O 2.144 (1)-2.543 (2) Angstrom]. The (ethylenediaminetetraacetato)antimonate anion, the aminoguanidinium cation and the lattice water are linked by hydrogen bonds into a two-dimensional network structure

Syntheses, crystal structures and magnetic properties of two honeycomb-layered bimetallic assemblies, K2[NiII(cyclam*)]3[FeII (CN)6]2 · 12H2O and [NiII(cyclam)]3[FeIII (CN)6]2 · 16H2O

Two bimetallic assemblies, K2[NiII(cyclam)]3[FeII (CN)6]2 · 12H2O (1) and [NiII(cyclam)]3[FeIII (CN)6]2 · 16H2O (2) (cyclam = 1,4,8,11-tetraazacyclotetradecane), were obtained by reaction of K4[Fe(CN)6] and [Ni(cyclam)](ClO4)2 in aqueous media at different temperatures. Their crystals were structurally determined and magnetic properties were studied. Both of the compounds have honeycomb-layered structures, which are formed by Fe6Ni6 units linked through the cyanide bridges. Structure (1) consists of polyanions containing NiII-N≡C-FeII linkages and K+ cations, while structure (2) is a two-dimensional neutral layer containing NiII-N≡C-FeIII linkages. The magnetic properties of (1) and (2) have been investigated in the 5-300 K range. Compound (1) exhibits a weak antiferromagnetic interaction with Weiss constant Θ = -0.35 K; compound (2) shows ferromagnetic intralayer and antiferromagnetic interlayer interactions.link_to_subscribed_fulltex