Comparative study of the antitumoral activity of phosphine-thiosemicarbazone gold(I) complexes obtained by different methodologies.

A series of phosphino-thiosemicarbazone gold(I) dinuclear complexes obtained by two different synthetic procedures have been prepared. All the compounds have been spectroscopically characterized including single crystal X ray diffraction analysis in some of cases. [Au(HL)Cl] (1), [Au(HL)]Cl (2) and [Au(HL)]Cl (3) have been prepared by chemical synthesis using a gold(III) salt as precursor; while [Au(L)] (4), [Au(L)]∙2CHCN (5) and [Au(L)] (6) have been isolated from an electrochemical synthesis (HL = 2-[2-(diphenylphosphanyl)-benzylidene]-N-R-thiosemicarbazone; HL: R = methyl, HL: R = methoxyphenyl, HL: R = nitrophenyl).

Alkali-metal-ion-directed self-assembly of redox-active manganese(III) supramolecular boxes.

The ability to organize functional molecules into higher dimensional arrays with well-defined spatial relationships between the components is one of the major goals in supramolecular chemistry. We report here a new route for the preparation of supramolecular boxes, incorporating two types of metal ions: (i) alkali-metal ions, which induce the supramolecular architecture and essentially play a structural role in the final compounds; (ii) manganese(III) ions, which are redox-active systems and give functionality to the new cages. Our results evidence that the size of the cavity inside the box can be tuned depending on the alkali metal used, a characteristic that gives this new family of compounds the potential to act selectively against different substrates.

Metal self-recognition: a pathway to control the formation of dihelicates and mesocates.

We have studied the factors that affect the formation of different metallosupramolecular architectures by metal direct self-assembly. A synthetic route has been developed to obtain mesocates or dihelicates selectively. For this purpose a series of five bisthiosemicarbazone ligands derived from 1,3-diacetylbenzene were designed and synthesised.

Versatile coordination behaviour of an asymmetric half-salen ligand bearing a dansyl fluorophore.

The coordinative chemistry of the tridentate half-salen ligand 5-(dimethylamino)-N-(2-((2-hydroxybenzylidene)amino)phenyl)naphthalene-1-sulfonamide (H(2)L, 1) has been studied by means of an electrochemical method. All of the complexes have been characterised using analytical and spectroscopic techniques. Ligand 1 and two nickel (6 and 7), copper (9), zinc (12) and cadmium (14) metal complexes have been studied by crystallography.

Influence of the geometry around the manganese ion on the peroxidase and catalase activities of Mn(III)-Schiff base complexes.

The peroxidase and catalase activities of eighteen manganese-Schiff base complexes have been studied. A correlation between the structure of the complexes and their catalytic activity is discussed on the basis of the variety of systems studied. Complexes 1-18 have the general formulae [MnL(n)(D)(2)](X)(H(2)O/CH(3)OH)(m), where L(n)=L(1)-L(13); D=H(2)O, CH(3)OH or Cl; m=0-2.

Manganese-Schiff base complexes as catalysts for water photolysis.

Four manganese(III)-Schiff base complexes (1-4) of formula [MnL(n)(H(2)O)(2)](2)(ClO(4))(2)·mH(2)O (n = 1-4; m = 0, 1) have been prepared. The multidentate H(2)L(n) Schiff base ligands consist of 3R,5R-substituted N,N'-bis(salicylidene)-1,2-diimino-2,2-dimethylethane, where R = OEt, OMe, Br or Cl. The complexes have been thoroughly characterized by elemental analysis, mass spectrometry, magnetic susceptibility measurements, IR, UV, paramagnetic (1)H NMR and EPR spectroscopies.

A sequentially assembled grid composed of supramolecular meso-helical nodes.

A unique case of a grid-of-mesocates sequentially assembled by supramolecular cobalt(II) meso-helical units connected through hydrogen bonding is reported.

Endogenous arene hydroxylation promoted by copper(I) cluster helicates.

A novel neutral triple-stranded hexanuclear copper(I) cluster helicate [Cu(I)(6)L(3)]·2CH(3)CN derived from a thiosemicarbazone ligand could be synthesized and crystallographically characterized. The MALDI mass spectrum of this complex suggests that the tetranuclear copper(I) cluster helicate [Cu(I)(4)L(2)] is also present in solution. These copper(I) cluster helicates are capable, in the presence of O(2), of hydroxylating the arene linker of their supporting ligand strands.

A water reduction process performed by zinc metal under very mild conditions.

Water reduction can be electrochemically promoted by zinc under very mild conditions, as demonstrated by the formation of the complex [Zn(H(2)O)(6)][Zn(3)(L)(3)(mu(3)-O)], whose anion consists of a Zn(3)O(4) cluster incorporating a mu(3)-oxo anion.

The coordination preferences of metal centres modulate superexchange coupling interactions in a metallo-supramolecular helical assembly.

A method to modulate the strength of the superexchange coupling interaction in dinuclear helical assemblies based on the coordination preferences of the metal centres is described.

A double-stranded dinuclear cadmium(II) helicate that assembles into chains in the solid state.

A [4+4] double-stranded cadmium dihelicate was afforded from an easily accessible thiosemicarbazone ligand; its crystal structure reveals the assembly of two enantiomers into dihelicate pairs, these pairs being further connected into infinite linear chains.

Sulfonamide-imines as selective fluorescent chemosensors for the fluoride anion.

Two new sulfonamide-type fluorescent chemosensors in organic media are reported. The two receptors, [N,N'-bis(2-tosylaminobenzylidene)-1,2-diaminoethane and N,N'-bis(2-tosylaminobenzylidene)-1,3-diamino-2-propanol], display marked changes in the fluorescence emission intensities as a result of deprotonation by basic anions, and show high selectivity for fluoride over other inorganic anions, such as acetate or dihydrogenphosphate. These results suggest that the presence of the imine group as an intramolecular H-bond acceptor enhances the selectivity of these sensors compared to previous examples in the literature.

Unprecedent isolation of a mixture of conformational and linkage isomers in a thiosemicarbazone cobalt mesocate.

A cobalt(II) thiosemicarbazonate mesocate has been structurally characterized as an unexpected mixture of conformational and linkage isomers. Moreover, we have shown that the absence of a nitrogen atom in the spacer of the helicand ligand H(2)L(a), enables the assembly of an achiral mesohelical complex in the case of Co(II) ions.

Coordinative trends of a tridentate thiosemicarbazone ligand: synthesis, characterization, luminescence studies and desulfurization processes.

The coordinative chemistry of the tridentate thiosemicarbazone ligand 2-pyridinecarboxaldehyde 4-N-ethylthiosemicarbazone (HL(Et)) has been explored by using an electrochemical methodology. All the complexes have been characterized using analytical and spectroscopic techniques. In the case of copper we have isolated two different complexes, with Cu(L(Et))(2).

Pentadentate thiosemicarbazones as versatile chelating systems. A comparative structural study of their metallic complexes.

We have prepared some transition and post-transition metal complexes derived from the pentadentate thiosemicarbazone ligand bis(4-N-ethylthiosemicarbazone)-2,6-diacetylpyridine H(2)L(Et), by both chemical and electrochemical procedures. The complexes have been synthesised and fully characterised, including the crystal structures for the ligand H(2)L(Et) and its manganese, cadmium and lead complexes. We have also performed multinuclear (109)Ag, (113)Cd, (119)Sn and (207)Pb studies for silver, cadmium, tin and lead compounds, respectively.

Metal-catalysed oxidation processes in thiosemicarbazones: new complexes with the ligand N-{2-([4-N-ethylthiosemicarbazone]methyl)phenyl}-p-toluenesulfonamide.

The coordination behaviour of a new thiosemicarbazone Schiff-base building block, N-{2-([4-N-ethylthiosemicarbazone]methyl)phenyl}-p-toluenesulfonamide, H2L1 (1), incorporating a bulky tosyl group, towards Mn II, Fe II, Co II, Ni II, Cu II, Zn II, Cd II, Ag I, Sn II, and Pb II has been investigated by means of an electrochemical preparative procedure. Most metal complexes of L1 have the general formula [M(L1)]2.nX (M=Mn, Fe, Co, Ni, Cu, Cd, Pb; n=0-4, X=H2O or CH3CN), as confirmed by the structure of [Pb(L1)]2 (15), in which the lone pair on lead is stereochemically active.

[Internal structure and standardised scores of the Torrance Test of Creative Thinking].

The present work sets out to study the internal structure of the Torrance Test of Creative Thinking (TTCT) and to establish standardised scores that will enable the test to be used in both a diagnostic and educational context. 649 students (319 girls and 330 boys), aged 5 to 12 years from various schools in Murcia and Alicante (SE Spain), took part in the study. The findings suggest that the psychometric characteristics of TTCT are satisfactory, and its internal structure can be attributed to three factors that are responsible for a high percentage of the variance (73.

Asymmetric self-assembly with atmospheric CO2 fixation of a pentanuclear carbonate NiI) complex based on dissimilar building blocks.

Formation in basic solution of an asymmetric pentanuclear carbonate Ni(II) complex with a compartmental ligand involves atmospheric CO(2) uptake, either by reaction of two slightly different dinuclear precursors that yield its di- and trinuclear "building blocks", or directly, by spontaneous self-organization of metal and ligand starting reactants.

Influence of the metal size in the structure of the complexes derived from a pentadentate [N(3)O(2)] hydrazone.

The influence of the metal size in the nuclearity of the complexes derived from the hydrazone ligand 2,6-bis(1-salicyloylhydrazonoethyl)pyridine [H(4)daps] has been investigated. We have synthesised a series of new complexes [M(H(x)daps)] x yH(2)O, (x = 2,3; y = 0-3) with M = Ag (1), Cd (2), Al (3), Sn (4) and Pb (6), using an electrochemical procedure. The crystal and molecular structures have been determined for the mononuclear complexes [Sn(H(2)daps)(H(2)O)(2)] x 4H(2)O (5) and [Pb(H(2)daps)(CN)][Et(4)N] (7).

Dinuclear Co(III)/Co(III) and Co(II)/Co(III) mixed-valent complexes: synthetic control of the cobalt oxidation level.

The reactivity of cobalt(II) salts towards H(3)L (2-(2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) was studied in different reaction conditions. Accordingly, the interaction of cobalt(II) acetate with H(3)L in methanol gives rise to the discrete complex [Co(III)(2)L(OAc)(2)(OMe)]*1.5H(2)O.

Dinuclear nickel complexes with a Ni(2)O(2) core: a structural and magnetic study.

The acetylacetonate complexes [Ni(2)L(1)(acac)(MeOH)] x H(2)O, 1 x H(2)O and [Ni(2)L(3)(acac)(MeOH)] x 1.5H(2)O, 2 x 1.5H(2)O (H(3)L(1) = (2-(2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine and H(3)L(3) = (2-(5-bromo-2-hydroxyphenyl)-1,3-bis[4-(5-bromo-2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) were prepared and fully characterised.

Novel peroxidase mimics: mu-Aqua manganese-Schiff base dimers.

The interaction of manganese(II) carboxylate salts [Mn(O(2)CR)(2), where R=ethane, pentane] with H(2)L(1) [N,N'-bis(3-methoxy-2-hydroxybenzaldehyde)-1,2-phenylenediamine] and H(2)L(2) [N,N'-bis(3-ethoxy-2-hydroxybenzaldehyde)-1,2-phenylenediamine] was studied. MnL(1)(O(2)CEt)(H(2)O) (1), MnL(1)(O(2)CPe(n))(H(2)O) (2), MnL(2)(O(2)CEt)(H(2)O)(2) (3) and MnL(2)(O(2)CPe(n))(H(2)O)(2) (4) were isolated and thoroughly characterised by elemental analysis, FAB mass spectrometry, infrared and (1)H NMR spectroscopy, magnetic susceptibility measurements, molar conductivities, and cyclic and normal pulse voltammetry. Compounds 1 and 2 were crystallographically characterised revealing a tetragonally elongated octahedral geometry for the manganese coordination sphere and also a dimeric nature through mu-aqua bridges.

Ferromagnetism in dinuclear copper(II)-phenolate complexes with exogenous O-donor bridges: a comparative study.

The copper(II) complex Cu2L(OAc)(H2O)3.5, 1 x 3.5H2O was obtained and its reactivity in a basic medium investigated.

Self-assembly of a tetranuclear Ni4 cluster with an S = 4 ground state: the first 3d metal cluster bearing a mu4-eta2:eta2-O,O carbonate ligand.

Reaction of nickel(II) acetate with H(3)L (2-(5-bromo-2-hydroxyphenyl)-1,3-bis[4-(5-bromo-2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine) yields [Ni(2)L(OAc)(H(2)O)(2)].3MeCN.2H(2)O (1.