Kinga Suwinska

Dioxovanadium(V) Schiff base complexes of N-methyl-1,2-diaminoethane and 2-methyl-1,2-diaminopropane with aromatic o-hydroxyaldehydes and o-hydroxyketones: synthesis, characterisation, catalytic properties and structure

Abstract Nineteen new dioxovanadium(V) complexes with unsymmetrical tridentate Schiff base ligands, obtained by a single condensation of 2-methyl-1,2-diaminopropane or N-methyl-1,2-diaminoethane with salicylaldehyde and its derivatives, 2-hydroxy-1-naphthaldehyde, 2-hydroxyacetophenone, 1-hydroxy-2-acetonaphthone and 2-hydroxybenzophenone, were prepared. The complexes were characterized by their 1H and 51V NMR, IR, and UV–Vis spectra. Crystal structure of the 2-(4-amino-4-methyl-2-aza-1-penten-1-yl-κ2N)-3,5-dimethoxyphenolato-κO-dioxovanadium(V), VO2(C13H19N2O3), has been obtained by X-ray diffraction studies. The structure revealed a rarely encountered in VO2(tridentate Schiff base) complexes a distorted trigonal-bipyramidal coordination geometry. The complexes comprising ligands derived either from N-methyl-1,2-diaminoethane or 2-methyl-1,2-diaminopropane and 5-methoxysalicylaldehyde catalyse the oxidation of thioanisole to the corresponding sulfoxide by cumene hydroperoxide.

Upper rim substituted thiacalix[4]arenes

Abstract The synthesis and structure of new tetrahydroxythiacalix[4]arenes, existing in the cone conformation and possessing reactive bromide, chloromethyl or diorganylphosphoryl groups on the upper rim of the macrocycle are described. The molecular structure of tetrakis(diisopropoxyphosphorylmethyl)thiacalix[4]arene was examined by X-ray crystallography.

A polynuclear complex, {[Cu(bpe)2](NO3)}, with interpenetrated diamondoid networks: synthesis, properties and catalytic behavior

A polynuclear complex {[Cu(bpe)2](NO3)} (1), with five-fold interpenetrated diamondoid nets, was synthesized following a hydrothermal procedure, starting from a copper(II) salt, Cu(NO3)2·2.5H2O, and using a molar ratio Cu(NO3)2 : monoethanolamine : bpe : H2O of 1 : 3 : 1 : 500. The well stirred mixture was introduced into a Teflon-lined stainless steel autoclave, heated at 423 K, and kept at this temperature for 3 days. Red single crystals containing complex 1 were fully characterized by chemical analysis, FTIR, single-crystal X-ray diffraction, powder XRD, DR-UV-Vis, TG–heat flow analysis, sorption isotherms of N2 at 77 K, and X-ray photoelectron spectroscopy (XPS). The characterization results indicated that these crystals corresponded to a copper–organic network with a microporous-like structure in which part of the channels are blocked by water molecules and nitrate ions. The synthesis led to a structure in which all the Cu ions were well stabilized as a Cu(I) species, although the precursor was a Cu(II) compound. This structure exhibits remarkable properties: high thermal stability and capacity to totally exchange NO3− anions, without causing any damage to the microporous texture. The catalytic behavior was investigated in NO decomposition and NO reduction with hexane in the presence of O2, revealing very interesting and high catalytic activity. Cu was well preserved in a Cu(I) state after the catalytic tests, which provided new information about the mechanism of NO reaction on copper.

Conformational extremes in the supramolecular assemblies of para-sulfonato-calix[8]arene

Two complex solid state structures of para-sulfonato-calix[8]arene are described, showing extremes in the macrocyclic conformation; one is planar and nearly circular, the other an inverted double cone. The differences in the molecular conformations lead to highly different packing arrangements in the structures.

Geometrical and inclusion considerations in the formation of hexagonal nanotubes of calix[4]arene di-methoxycarbonyl methyl ester and acid

The crystal structures of calix[4]arene di-methoxycarbonyl-methyl ester and carboxylic acid have been resolved. Interestingly, the packing for both molecules is in the form of crystal symmetry defined hexagonal helical nanotube architecture, but with the methyl ester derivative showing an extended form of the helix with regard to that formed by the carboxylic acid derivative. The addition of one carbon in the ester group leads to inclusion of the ethyl ester within a neighbouring calixarene cavity, and in consequence the packing becomes radically different.

Clathrate inclusiom compounds of bis(isothiocyanato) tetrakis (4-methylpyridine) nickel II: II1. Arrangement of guest molecules in the β-Ni(NCS)2(4-methylpyrldine)4 porous crystals

Abstract In this paper crystal structures of three tetragonal 14 1 /a β-Ni(NCS) 2 (4-Methylpyridine) 4 clathrates containing p-xylene (1:1), m-xylene (1:1) and methanol (2:1 mole of guest/mole of host), respectively, as the guest components are reported and discussed. The guest molecules were found to occupy centrosymmetric cavities in the hoat structure. Non-centrosymmetric m-xylene molecules are disordered to at least two orientations interrelated by inversion; methanol molecules enter the cavities as centrosymmetric pairs.

1,3-Dipolar cycloaddition of a nitrone derived from (S)-malic acid to α,β-unsaturated δ-lactones

Abstract 1,3-Dipolar cycloaddition of nitrone 7 to α,β-unsaturated δ-lactones: non-chiral 2, racemic mixture 3/3ent, d -glycero 3 and d -threo 15 proceeds with high stereoselectivity in the case of 2 and 15, and with a significant kinetic resolution in the case of the racemate 3/3ent. The endo approach of reactants was not observed. CD-spectroscopy proved an attractive tool for determination of the absolute configuration of cycloadducts.

Phase and X-ray study of clathrate formation in the tetraisoamylammonium fluoride-water system

The phase diagram of the binary (i-C5H11)4NF-water system has been studied in the clathrate formation region. Three polyhydrates have been discovered, two of which (1∶38.9 and 1∶32.7) are the known orthorhombic and tetragonal phases:Pbmn,a=11.88,b=21.53,c=12.70 Å,ρmeans=1.019 g cm-3 (0°C), m.p.=32.4°C andP42/m, a=23.729,c=12.466 Å,ρmeans=1.062 g cm-3, (0°C), m.p.=31.2°C, respectively. A single crystal X-ray analysis of the novel clathrate hydrate (i-C5H11)4NF·27 H2O is reported. This new clathrate hydrate is tetragonal,I4I/a, witha=16.894(5),c=17.111(2) Å,Z=4, (−50°C), and m.p.=34.6°C. Each (i-C5H11)4N+ cation occupies a four-chamber cavity built of 15-hedra 71635942 (idealized description), with small vacant 5444 cavities filling the intervening space.

Solid state structures of the complexes between the antiseptic chlorhexidine and three anionic derivatives of calix[4]arene

The solid state structures of the complexes between antiseptic chlorhexidine and three anionic calix[4]arene derivatives are described. Each of the three calixarenes shows typical self-organisation in the solid-state that will further impose a specific complexation of the active molecule in the co-crystal.

The role of template in the synthesis of meso-hexamethyl- meso-hexaphenyl-calix[6]pyrrole: trihalogenated compounds as templates for the assembly of a host with a trigonal cavityElectronic supplementary data (ESI) available: Figs. 1 and 2 showing atom numbering. See http://www.rsc.org/suppdata/cc/b1/b106162n/

Trihalogenated compounds act as effective and selective templates in the template-assisted synthesis of meso-hexaphenyl-calix[6]pyrrole.