Synthesis and structural characterization of dialkyltin complexes of N-salicylidene-L-valine

The synthesis and characterization of five new chiral dialkyltin complexes of N-salicylidene-L-valine, [2-O-3-R-5-R'C6H2C(H)=NCH(CH(CH3)2)C(O)O]SnR''2 (R, R', R'' = H, H, Me (1); H, Br, Me (2); OMe, H, Et (3); Br, Br, n-Bu (4); CH(OMe)2, Me, n-Bu (5)), have been reported. Compounds 1-5 are all (S)-enantiomers, and their crystal structures have been studied. Compound 1 displays a trimeric macrocyclic structure in which the coordination environment of each tin atom is a distorted [SnC2NO3] octahedron. In complexes 2-5, the tin atom has an intermediate geometry between trigonal bipyramidal and square pyramidal, and 3 is closer to a square pyramid. In crystals, a zigzag supramolecular chain is formed by the intermolecular C-H…O, O-H…O or Sn…O interactions.

Synthèse, caractérisation et l’activité anti-tumorale d’un complexe organo-étain carboxylique

Le problème du cancer constitue à l’échelle planétaire une préoccupation de santé publique. Il a été longtemps sous-estimé par les structures sanitaires en Africaines à cause de la pression exercée par les maladies transmissibles et carentielles sur les services de santé. Son influence négative peut être pourtant réduite grâce au programme de lutte contre le cancer mis en place. Ce programme nécessite la mobilisation des ressources humaines, matérielles, intellectuelles, services de santé, l’associations des malades de cancer. Dans le souci de remédier à ce problème de santé publique, un complexe d’organo-étain carboxylique de formule [(Bu)2Sn]4(L1)2O3(Br)2] a été synthétisé. La molécule obtenue a été caractérisée par les méthodes d’analyses élémentaires, spectroscopiques (RMN 1H et FT-IR) et par la technique de diffraction aux rayons X. Il a été constaté que cette molécule présente un fragment Sn4O2Br2 unit dont l’interaction Sn…O, conduit à la formation d’une chaine supramoléculaire. Son activité anti-tumorale sur les différentes cellules a présentée des résultats significatifs.Mots clés : Synthèse, complexe d’organo-étain carboxylique, caractérisation, chaine supramoléculaire, anti-tumorale. English Title: Synthesis, characterization and anti-tumor activity of complex organotin carboxylate The cancer problem is a global public health concern. It has long been underestimated by health structures in Africa because of the pressure exerted by communicable and deficient diseases on health services. Its negative influence can however be reduced thanks to the cancer control program put in place. This program requires the mobilization of human, material, intellectual resources, health services, associations of cancer patient. In order to remedy this public health problem, an organotin carboxylic complex of formula [(Bu)2Sn]4L1)2O3(Br)2] has been synthesized. The molecule obtained was characterized by elementary, spectroscopic analysis methods (1 H NMR and FT-IR) and by the X-ray diffraction technique. It was found that this molecule has a Sn4O2Br2 unit fragment whose interaction Sn…O leads to the formation of a supramolecular chain. Its anti-tumor activity on the various cells has presented significant results.Keywords: Synthesis, organotin carboxylic complex, characterization, supramolecular chain, anti-tumor.

The first report of a tetra-azide bound mononuclear cobalt(iii) complex and its comparative biomimetic catalytic activity with tri-azide bound cobalt(iii) compounds

Three new azide-bound cobalt(iii) complexes derived from three different triamines with extensive hydrogen bonded supramolecular chain structures and the role of their structural factors in oxidative coupling of o-aminophenols have been reported.

Steric control of supramolecular association in structures of Zn(S2COR)2 with N,N′-bis(pyridin-4-ylmethyl)oxalamide

The crystal and molecular structures of the one-dimensional coordination polymer [Zn(S2COEt)2(4LH2)]n (1) and binuclear [Zn(S2COCy)2]2(4LH2) (2) are described, where 4LH2 is N,N′-bis(pyridin-4-ylmethyl)ethanediamide. In 1, the Zn(S2COEt)2 entities are linked by bidentate bridging 4LH2 ligands through the pyridyl-N atoms to generate a twisted supramolecular chain. As a result of monodentate xanthate ligands, the N2S4 donor set defines a distorted tetrahedral coordination geometry and, crucially, allows the participation of the non-coordinating sulfur atoms in supramolecular association. Thus, in the crystal amide-N–H···O(amide) and amide-N–H···S(thione) hydrogen bonds link chains into a three-dimensional architecture. The substitution of the ethyl group in the xanthate ligand with a cyclohexyl group results in very different structural outcomes. In 2, a binuclear molecule is observed with the coordination geometry for zinc being defined by chelating xanthate ligands and a pyridyl-N atom with the NS4 donor set defining a highly distorted geometry. In the molecular packing, amide-N–H···S(thione) hydrogen bonds stabilise a supramolecular chain along the a-axis and these are connected into a three-dimensional arrangement by methylene-C–H···O and methylene-C–H···π(pyridyl) interactions. The relative importance of the specified intermolecular interactions and weaker, contributing contacts has been revealed by an analysis of the calculated Hirshfeld surfaces of 1 and 2.

A supramolecular chain of dimeric Dy single molecule magnets decorated with azobenzene ligands

DyIII dimers decorated with photo-isomerizable azobenzene ligands behave as single-molecule magnets and self-organize into a supramolecular chain. Ab initio calculations, magnetic and optical properties are reported.

A one-dimensional supramolecular chain based on [H2V10O28]4− units decorated with 4-dimethylaminopyridinium ions: an experimental and theoretical characterization

One-dimensional supramolecular structure with [H2V10O28]4− units was synthesized and experimental-theoretical characterized as potential releasing prodrug of the decavanadate ion.

Methyl 4-{N′-[(1E)-1-(pyrazin-2-yl)ethylidene]hydrazinecarbonyl}benzoate

The title Schiff base, C15H14N4O3, was synthesized by the condensation reaction between caprylic hydrazide and 2-acetylpyrazine. There are two independent pseudo-enantiomeric molecules, A and B, in the asymmetric unit that differ mainly in the orientation of the hydrazone units. For example, the dihedral angles between the benzene and pyrazine rings are 20.836 (13) (A) and 15.701 (14)° (B). The molecular packing features N—H...O hydrogen bonds that lead to a twisted supramolecular chain along the b-axis direction. The presence of C—H...O interactions consolidates the chains into a three-dimensional architecture. The studied sample was a two-component twin.

Controllable supramolecular chain aggregation through nano-steric hindrance functionalization for multi-color larger-area electroluminescence

Suppression of hierarchical chain aggregationvianano-steric hindrance functionalization is an effective strategy to restrain long-wavelength emission and improving the device performance.