Rosa Pedrido

University of Santiago de Compostela | USC · Faculty of Chemistry

A Química Bioinorgánica representa a disciplina emerxente da ciencia que estuda o papel que xogan os elementos inorgánicos en medios biolóxicos. Os elementos químicos inorgánicos inciden nos organismos vivos por múltiples vías. Nalgúns casos son esenciais para o desenvolvemento de funcións vitais dos organismos, ao estar presentes de forma natural...

Nesta práctica experimental, exploramos o fenómeno do “efecto salino” sobre diferentes disolucións, para tratar de comprender que son e como actúan as forzas intermoleculares. Realizaremos esta exploración mediante a observación da separación de fases no seguinte experimento: a unha disolución composta por auga e acetona, engádeselle sal de mesa (c...

The number and position of bulky groups in the skeleton of the ligand precursor influence whether helicates or mesocates are obtained.

Manganosalen complexes are a class of catalytic antioxidants with beneficial effects against different neurological disorders according to various in vitro and in vivo studies. The interest in the factors that determine their antioxidant activity is based on the fact that they are key to achieving more efficient models. In this work, we report a se...

In the present work, we report a neutral dinuclear copper(II) complex, [Cu2(L1)(OH)], derived from a new [N,O] donor Schiff base ligand L1 that was formed after the endogenous hydroxylation of an initial carbamate Schiff base H2L coordinated with copper ions in an electrochemical cell. The copper(II) complex has been fully characterized using diffe...

This review aims to analyze the emerging number of studies on biological media that describe the unexpected effects of different natural bioactive antioxidants. Hormetic effects, with a biphasic response depending on the dose, or activities that are apparently non-dose-dependent, have been described for compounds such as resveratrol, curcumin, feru...

Cluster helicates are a new type of supramolecular architectures that consist in a metal cluster wrapped around by ligands arranged in a helical mode. This class of compounds combines the...

Thiosemicarbazones are biologically active substances whose structural formula is formed by an azomethine, an hydrazine, and a thioamide fragments, to generate a R2C=N–NR–C(=S)–NR2 backbone. These compounds often act as ligands to generate highly stable metal–organic complexes. In certain experimental conditions, however, thiosemicarbazones undergo...

A xeración dos novos materiais que están a aparecer e, de modo especial, os nanomateriais están abrindo as portas da transformación das industrias da actualidade e, tamén, a transformación das nosas propias vidas. Fálase de familias de novos materiais moito máis eficaces, como os bidimensionais: grafeno, grafino, carbinos, siliceno, xermaneno, esta...

The study of the inherent factors that influence the isolation of one type of metallosupramolecular architecture over another is one of the main objectives in the field of Metallosupramolecular Chemistry. In this work, we report two new neutral copper(II) helicates, [Cu2(L1)2]·4CH3CN and [Cu2(L2)2]·CH3CN, obtained by means of an electrochemical met...

The study of the inherent factors that influence the isolation of one type of metallosupramolecular architecture over another is one of the main objectives in the field of Metallosupramolecular Chemistry. In this work, we report two new neutral copper(II) helicates, [Cu2(L1)2]·4CH3CN and [Cu2(L2)2]·CH3CN, obtained by means of an electrochemical met...

The design of artificial helicoidal molecules derived from metal ions with biological properties is one of the objectives within metallosupramolecular chemistry. Herein, we report three zinc helicates derived from a family of bisthiosemicarbazone ligands with different terminal groups, Zn2(LMe)2∙2H2O 1, Zn2(LPh)2∙2H2O 2 and Zn2(LPhNO2)23, obtained...

The use of perchlorato ancillary ligands, with relatively low coordinating ability, nicely illustrates a rich structural diversity in thiosemicarbazonecopper(II), TSC-Cu(II), systems. Five compounds with formulae {[CuL(OH2)][CuL(OClO3)]}n·nClO4·2nH2O (1), [{CuL(OClO3)}2] (2), [Cu(HL)(OClO3)2(OH2)]...

The design of artificial helicoidal molecules derived from metal ions with biological properties is one of the objectives within Metallosupramolecular Chemistry. Herein, we report three zinc helicates derived from a family of bisthiosemicarbazone ligands with different terminal groups, Zn2(LMe)2∙2H2O 1, Zn2(LPh)2∙2H2O 2 and Zn2(LPhNO2)2 3, obtained...

Thiosemicarbazones are interesting organic skeletons due to their great coordinative versatility and their interesting biological and pharmacological properties, as well as their structural diversity. However, the isolation of their monovalent coinage metal complexes, such as Cu(I), Ag(I) and Au(I), is a partially studied field, since co-ligands wi...

We report two different approaches to isolate neutral and cationic mesocate-type metallosupramolecular architectures derived from coinage monovalent ions. For this purpose, we use a thiocarbohydrazone ligand, H2L (1), conveniently tuned with bulky phosphine groups to stabilize the MI ions and prevent ligand crossing to achieve the selective formati...

The mechanism of carbamate activation promoted by different metal ions has been explored in this work. The reaction of the carbamate ligand H2L with chloride metal salts (M = Ni, Cu, Zn, Cd) leads to the coordination of the metal ions to the ligand, causing hydrolysis of the systems. This self-immolation process results in mononuclear dihydrazone c...

We show the first example of a bisthiosemicarbazone silver double-tetranuclear cluster helicate [Ag 4 L 2 ] 2 obtained by electrochemical synthesis which undergoes a rare desulfurization process giving rise to a cationic silver dihelicate [Ag 2 (H 2 L) 2 ]SO 4 .

The asymmetric hydrazone-thiosemicarbazone ligand H2L was synthesized in two stages by means of a double-condensation reaction. The potentially dianionic and pentadentate [N3SO] organic ligand H2L possesses two flexible bidentate [NS/NO] domains separated by a pyridine spacer, which could stabilize a wide variety of metal ions, giving rise to diffe...

In this work, four manganese(II) complexes derived from the ligands H2L¹-H2L⁴, that incorporate dansyl or tosyl fluorescent dyes, have been investigated in term of their antioxidant properties. Two of the manganese(II) complexes have been newly prepared using the asymmetric half-salen ligand H2L² and the thiosemicarbazone ligand H2L³. The four orga...

As medidas de confinamento derivadas da pandemia da COVID afondaron na necesidade do desenvolvemento de ferramentas educativas en liña ás que o alumnado poda acceder en remoto autonomamente de maneira asíncrona. Neste artigo descríbese a nosa proposta dun curso aberto de química en liña a partir dun enfoque experimental, baseado principalmente en p...

No século XVIII non había táboa periódica, pero si existía xa a Química Inorgánica, que os franceses chamaban “Chemie Minerale”. Ata finais do século XVIII e desde os tempos alquímicos, as químicas de todos os tempos miraban canto estaba ao seu redor e investigaban para coñecelo mellor e utilizalo na súa vida cotiá. Deste xeito foron descubrindo e...

Manganosalen complexes are coordination compounds that possess a chelating salen-type ligand, a class of bis-Schiff bases obtained by condensation of salicylaldehyde and a diamine. They may act as catalytic antioxidants mimicking both the structure and the reactivity of the native antioxidant enzymes active site. Thus, manganosalen complexes have b...

Manganosalen complexes are coordination compounds that possess a chelating salen-type ligand, a class of bis-Schiff bases obtained by condensation of salicylaldehyde and a diamine. They may act as catalytic antioxidants mimicking both the structure and the reactivity of the native antioxidant enzymes active site. Thus, manganosalen complexes have s...

Neste artigo temos como obxectivo dar a coñecer como é o mundo dun tipo de nanomateriais metálicos chamados Puntos Cuánticos (PCs) ou, en terminoloxía inglesa, os Quantum Dots (QDs). A pretensión deste traballo é a de estudar que se entende hoxe por Puntos Cuánticos, como é a súa constitución, cal é o seu tamaño e forma; de que tipo resulta ser o s...

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. [Au2(HL1)Cl2] (1), [Au2(HL2)2]Cl2 (2) and [Au2(HL3)2]Cl2 (3) have been prepared by ch...

Hai máis de 40 anos, un de nós e outros profesores do departamento de Química Inorgánica da USC, publicamos o libro “Química Inorgánica. Esquema orientativo y cuestiones fundamentales”. Nese libro pretendiamos desenvolver máis e mellor o temario da materia de Química Inorgánica nesa época e, ao mesmo tempo, facer propostas de cuestións de dificulta...

A química é a ciencia do por qué e do para qué. Este capítulo, cuxa escritura estamos iniciando, tratará de dar resposta a estas preguntas no tema obxecto do libro; o Ano Internacional do Sistema Periódico, así como da súa importancia na comprensión e no estudo da química. O por qué está relacionado coa historia da química e do propio sistema perió...

O ano 2019 foi declarado ANO INTERNACIONAL DA TÁBOA PERIÓDICA polas Nacións Unidas, para conmemorar os 150 anos da publicación por Dimitri Mendeleev da súa táboa periódica e por se celebrar o centenario da creación da IUPAC; pero non se escoita falar nada polo noso País de tal acontecemento. Ao noso grupo de investigación educativa CienciaNOSA pare...

Neste capítulo pretendemos ir amosando como se foron descubrindo moitos dos distintos elementos metálicos nos seus minerarios e como se foron inventando os distintos métodos de beneficiación, para chegar a obtelos puros e preparar as diversas aliaxes de interese industrial que contribuíron ao desenvolvemento da historia da humanidade. Faremos unha...

A tri-catalytic compartmentalized system that immobilizes metallic species to perform one-pot sequential functiona-lizations is described: a three-dimensional (3D)-printed palladium monolith, ferritic copper(I) magnetic nanoparticles and a 3D-printed polypropylene capsule containing copper(II) loaded onto polystyrene-supported 1,5,7-triazabicyclo[4...

The effect of the ligand and/or metal-related factors on the formation of tristhiosemicarbazone metallosupramolecular complexes has been studied in this work. The crystal structures of zinc(II) and lead(II) tristhiosemicarbazone mesocates and a hydrolyzed cadmium(II) helicate let us better rationalize some factors involved in the selective formatio...

The ability of Ba2Mn2 supramolecular (1) box to split water has been studied by means of Water photolysis experiments.DFT calculations show that (1) can follow a mechanism with successive hudrogen abstrations from water molecules bound to the metal ion by optically excited p-benzoquinone

The reaction of 2-cyanopyridine and Mn(II) in methanol solution led to the formation of a Mn4L6Cl2 cluster 1 containing O-methyl picolimidate as a ligand (L). The coordination of 2-cyanopyridine to the Mn(II) ion as a chelating bidentate ligand activated the CN triple bond which subsequently suffered a nucleophilic attack by CH3OH. Complex 1 was ch...

The oxygen-evolving complex (OEC) is the native enzyme that catalyzes the oxidation of water in natural photosynthesis. Two new classes of manganese cluster complexes of formula Ba2Mn2L12(H3L1)2(CH3OH)4 1 and Mn4L26Cl2 2 were prepared (H4L1 = N,N′-(ethane-1,2-diyl)bis(2-hydroxybenzamide); L2 = methyl picolinimidate) and characterized by standard te...

1. INTRoDuCIÓN O cambio máis importante atopado na his-toria, dentro do desenrolo da ciencia, dáse no século XVIII: dito século chámase o da Ilustración. É o século da revolución cientí-fica. Xa desde o século XVII existía interese no estudo dos fenómenos naturais; investi-gábase a natureza observándoa e reflectindo os resultados en textos científi...

The effect of the metal ion and ligand design on the enantioselectivity and linkage isomerization of neutral cobalt and zinc bisthiosemicarbazone metallohelicates has been investigated in this work. The electrochemical synthesis has afforded the enantioselective formation of chiral pure cobalt helicates, and the  isomer of a single enantiomer ha...

A dinuclear Pb(ii) mesocate has been prepared with an unprecedented four-coordinated kernel in which the Pb(ii) lone pair is stereochemically active. This is the first time that this effect has been observed in a supramolecular Pb(ii) helicate or meso-helicate.

Gold compounds to be obtained by the direct electrochemical oxidation of a noble metal are reported. This achievement provides an alternative procedure to obtaining neutral gold compounds with potential medical or catalytic applications.

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 supra...

The synthesis of a new asymmetric ligand (E)-4-bromo-2-(((2-((5-bromo-2-hydroxybenzyl)(methyl)amino)ethyl)imino)methyl)phenol, which was conceived to model the asymmetry in the active site of peroxidase/catalase mimics, is reported. The new synthetic route involves seven steps: 1) obtention of phthalimido-acetal; 2) Acetal deprotection; 3) Synthesi...

Caroline Lucretia Herschel: A dama que domou os cometas e a vida e obra desta extraordinaria muller que foi unha pioneira nas investigacións astronómícas do século XIX que foi e segue a ser una grande descoñecida

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. Name...

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 (...

The isolation of the first case of a ‘grid-of-helicates’ allowed us to rationalize the formation of extended 1D-chains or 2D-grid sheets of helicates with Cd(II) ions.

The reaction of the phosphine thiosemicarbazone ligands HLPH and HLPMe with Au(I) ions yields the gold complexes [Au(3)(HLPH)(2)Cl(2)]Cl·2MeOH (1·2MeOH) and [Au(2)(HLPMe)Cl(2)] (2). The structures determined by X Ray diffraction, [Au(3)(HLPH)(2)Cl(2)]Cl·4MeOH (1·4MeOH) and [Au(2)(HLPMe)Cl(2)](2) (2), are the first examples of gold(I) thiosemicarbaz...

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

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...

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.

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.

The reactivity of the phosphino-thiosemicarbazone ligand 2-(2-(diphenylphosphino)benzylidene)-N-ethylthiosemicarbazone (HLPEt) toward M(I) halides (M = Cu, Ag, Au) was studied. The complexes obtained, with formulae [Cu(HLPEt)(2)]Br (1), [Cu(HLPEt)(2)]I.2H(2)O (2), [Ag(HLPEt)(LPEt)].3H(2)O (3), [Au(2)(HLPEt)(2)Cl]Cl.CH(3)OH (4) were satisfactorily c...

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.

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 selectivit...

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...

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.

The reaction of silver acetate and silver nitrate with the new phosphinethiosemicarbazone ligand 2-(2-(diphenylphosphino)benzylidene)-N-ethylthiosemicarbazone (HLPEt) gave rise to the complexes [Ag(LPEt)](4).2MeOH (1) and [Ag(2)(LPEt)(HLPEt)](2).(NO(3))(2) (3). Slow crystallization of the mother liquors obtained from the synthesis of 1 and 3 afford...

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)...

We investigated the coordinative behaviour of the phosphanylthiosemicarbazone ligand 2-[2-(diphenylphosphanyl)benzylidene]-N-phenylthiosemicarbazone (HLPPh) towards coinage MI metal ions (M = Cu, Ag, Au). The complexes obtained, with formulae [Cu(HLPPh)2]Br (1), [Cu(HLPPh)2]I·H2O (2), [Ag(HLPPh)(NO3)]·3H2O (3) and [Au2(HLPPh)2]·3CH3OH (4), were sat...

We have developed an easy and flexible synthetic methodology to obtain lipid chains containing methanothiosulfonate terminal groups with the aim to attach them to natural proteins as functional groups. There are many proteins found in nature that are modified by lipids, and this is a key part of their function. For example, the prion protein is att...

The tetraamine dinucleating ligand L, which bears naphthalene moieties at both ends, behaves as a combinatorial logic circuit for a molecular half-subtractor in the presence of ZnII ions.

The neutral single-stranded monohelicate [Pd(HL)]·2(CH3CN) (1) aggregates in the solid state to give an infinite 1D supramolecular chain through either the cooperative action of hydrogen bonding and π-stacking interactions or by aromatic π-stacking alone.

The aim of the work described here was to test the general applicability of our recently reported route to cluster helicates and to carry out a systematic study to relate the structural and coordinative properties of the organic strands with the microarchitectures of the resulting cluster helicates. Nine new ZnII, CuI and AgI complexes were prepare...

The reaction of silver acetate with a phosphinothiosemicarbazone ligand, HLPPh, yielded the tetranuclear silver compound [Ag 4(LPPh) 4].2MeOH ( 1), which after recrystallization results in the cocrystallization of two different silver clusters, [Ag 4(LPPh) 4] (a)[Ag 4(LPPh) 4] (b).8MeOH ( 2). The factors involved in the assembly of tetranuclear com...

We report the first structural evidence in the solid state of discrete water octamers with a 1,4-diaxially substituted hexameric chairlike conformation. These units were found to act as supramolecular glue in the aggregation of Pd(II) monohelicates to give a three-dimensional network through hydrogen-bonding.

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 procedu...

The metal complexes studied in this report derive from the ligand 4‐ N ‐phenylthiosemicarbazone‐2‐pyridinecarboxaldehyde, abbreviated HL, and the transition and post‐transition metals manganese, iron, cobalt, nickel, copper, silver, zinc, cadmium and lead. The new complexes were obtained by an electrochemical procedure and were found to be of the f...

The synthesis and structural and spectroscopic characterisation of 12 manganese(III)–Schiff-base complexes of the formula [MnLn(H2O/CH3OH)2](ClO4)(mH2O) (m = 0, 1) are described. The multidentate H2Ln and H4Ln Schiff-base ligands were obtained by condensation of different diamines (1,2-diaminoethane, 1,2-diamino-2-methylethane, 1,2-diamino-2,2-dime...

The interaction of the transition and post‐transition metals manganese, iron, cobalt, nickel, zinc, cadmium and lead, with the ligand 4‐ N ‐methylthiosemicarbazone‐2‐pyridinecarboxaldehyde (HL) through an electrochemical procedure has been investigated. The novel complexes obtained via this synthetic route have the general formulae [M(L) 2 ](H 2 O)...