A5043506178- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Magnetism in coordination complexes
- Organic and Molecular Conductors Research
- Crystallography and molecular interactions
- Metal-Organic Frameworks: Synthesis and Applications
- Molecular Junctions and Nanostructures
- Lanthanide and Transition Metal Complexes
- Solid-state spectroscopy and crystallography
- Metal complexes synthesis and properties
- Organometallic Complex Synthesis and Catalysis
- Electron Spin Resonance Studies
- Metalloenzymes and iron-sulfur proteins
- Perovskite Materials and Applications
- Metal-Catalyzed Oxygenation Mechanisms
- Porphyrin and Phthalocyanine Chemistry
- Rare-earth and actinide compounds
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Photochemistry and Electron Transfer Studies
- Organic Chemistry Cycloaddition Reactions
- Inorganic Chemistry and Materials
- Organometallic Compounds Synthesis and Characterization
- Advanced battery technologies research
- Crystal structures of chemical compounds
- Machine Learning in Materials Science
University of Lisbon
2014-2023
Instituto de Engenharia de Sistemas e Computadores Investigação e Desenvolvimento
2022
Instituto Superior Técnico
2003-2019
Rede de Química e Tecnologia
2011
TARH (Portugal)
2000-2009
University of Coimbra
2004
Atlântica Instituto Universitário
1988-1993
National Institute of Engineering, Technology and Innovation
1990-1991
The gold complexes n-Bu4N[Au(alpha-tpdt)2] (5), n-Bu4N[Au(dtpdt)2] (4) and n-Bu4N[Au(tpdt)2] (6) based on new dithiothiophene ligands (alpha-tpdt= 2,3-thiophenedithiolate, dtpdt=2,3-dihydro-5,6-thiophenedithiolate tpdt = 3,4-thiophenedithiolate) have been prepared characterised. These gold(III) are diamagnetic, but they can be oxidised with iodine to the paramagnetic compounds [Au(alpha-tpdt)2] (8), [Au(dtpdt)2] (7) n-Bu4N[[Au(tpdt)2]n-2] (9), which were isolated as fine powders exhibit...
We report the synthesis of iron(III) complex hexadentate Schiff base ligand nsal2trien obtained from condensation triethylenetetramine and 2 equiv. 2-hydroxy-1-naphthaldehyde. The study salt [Fe(nsal2trien)]SCN (1) by magnetic susceptibility measurements Mössbauer spectroscopy reveals a rather unique behavior that displays thermally induced spin crossover (SCO) with two well-separated steps at 250 (gradual transition) 142 K (steep transition). Single crystal X-ray structures were 294, 150,...
The FeIII complexes Fe(5-Br-qsal)2Ni(dmit)2·solv with solv = CH2Cl2 (1) and (CH3)2CO (2) were synthesized, their structural magnetic properties studied. While magnetization Mössbauer spectroscopy data of 1 showed a gradual spin transition, compound 2 evidenced an abrupt transition thermal hysteresis 13 K close to room temperature (T1/2 ↓ ∼273 T1/2 ↑ ∼286 K). A similar packing arrangement segregated layers cations anions was found for 2. In both low-spin, LS, structures there are large number...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLow-dimensional molecular metals bis(maleonitriledithiolato)bis(perylene)metal, metal = iron and cobaltVasco Gama, Rui T. Henriques, Gregoire Bonfait, Laura C. Pereira, Joao Waerenborgh, Isabel Santos, M. Teresa Duarte, P. Cabral, Manuel AlmeidaCite this: Inorg. Chem. 1992, 31, 12, 2598–2604Publication Date (Print):June 1, 1992Publication History Published online1 May 2002Published inissue 1 June...
Abstract A series of new M[(dcbdt) 2 ] − z complexes the dicyanobenzodithiolate (dcbdt) ligand with a range transition metals (M = Co, Pd, Pt, Cu, Au and Zn) in different oxidation states ( 0.4, 1, 2) were prepared as their n Bu 4 N salts characterised by X‐ray diffraction, cyclic voltammetry, EPR static magnetic susceptibility. Their properties are discussed comparison Ni Fe analogues described us recently. The structures these belong to four distinct groups: i) Zn II compound 10 is...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT(Perylene)Co(mnt)2(CH2Cl2)0.5: a mixed perylenecobalt complex as molecular and polymeric conductorVasco Gama, Rui T. Henriques, Gregoire Bonfait, Manuel Almeida, Auke Meetsma, Sander Van Smaalen, Jan L. De BoerCite this: J. Am. Chem. Soc. 1992, 114, 6, 1986–1989Publication Date (Print):March 1, 1992Publication History Published online1 May 2002Published inissue 1 March...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLow-dimensional molecular conductors (Per)2M(mnt)2, Per = perylene, mnt maleonitrile dithiolate, M copper or nickel: low- and high-conductivity phasesVasco Gama, Manuel Almeida, Rui T. Henriques, Isabel C. Santos, Angela Domingos, Sylvain Ravy, Jean Paul PougetCite this: J. Phys. Chem. 1991, 95, 11, 4263–4267Publication Date (Print):May 1, 1991Publication History Published online1 May 2002Published inissue 1...
A new compound, [Fe(5–Cl-qsal)2][Ni(α-tpdt)2].CH3CN, where α-tpdt = 2,3-thiophenedithiolate and H5–Cl-qsal N-(8-quinolyl)-5-chlorosalicylaldimine, was prepared structurally magnetically characterized. The crystal structure is based on an arrangement of alternate layers [Fe(5–Cl-qsal)2]+ cations [Ni(α-tpdt)2]− anions. magnetic measurements Mössbauer spectroscopy revealed hybrid behavior in this a ferromagnetic cluster-glass behavior, ascribed to the anions network, spin crossover (SCO) were...
The synthesis and characterization of the new aromatic ortho-dithiol, 4,5-dicyanobenzene-1,2-dithiol (3) is reported. This compound was used to prepare tetrabutylammonium salts novel nickel complexes; nickel(II) salt (nBu4N)2[Ni(dcbdt)2] (4), nickel(III) (nBu4N)2[Ni(dcbdt)2]2 (5), partially oxidized NiIII/IV (nBu4N)2[Ni(dcbdt)2]5 (6). (dcbdt = 4,5-dicyanobenzene-1,2-dithiolate). NiII complex presents a square-planar coordination geometry diamagnetic, while in paramagnetic NiIII Ni(dcbdt)2...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA novel trinuclear cobalt complex: crystal and electronic structure of perylene bis(maleonitriledithiolato)cobaltate (Per)4[Co(mnt)2]3Vasco Gama, Rui T. Henriques, Manuel Almeida, Luis Veiros, M. J. Calhorda, Auke Meetsma, Jan L. de BoerCite this: Inorg. Chem. 1993, 32, 17, 3705–3711Publication Date (Print):August 1, 1993Publication History Published online1 May 2002Published inissue 1 August 1993https://doi.org/10.1021/ic00069a027Request reuse...
Electrocrystallization from solutions of the dissymmetrical ET derivative cyanobenzene-ethylenedithio-tetrathiafulvalene (CNB-EDT-TTF) in presence triiodide I3- affords two different polymorphs (β″ and κ) with composition (CNB-EDT-TTF)4I3, both a bilayer structure donors. These differ packing patterns (β″- κ-type) donor molecules each layer, cases bifurcated C-N···H interactions effectively coupling head-to-head between layer pairs. Two β″ can be obtained degrees anionic ordering. In one...
Abstract The properties of the compounds family Per2M(mnt)2 with α phases are reviewed taking into account recent experimental results. perylene chains, responsible for electronic conduction undergo Peierls transitions at low temperatures. In cases M= Pt, Pd and Ni, chains M(mnt)2 − units localised spins have exchange interactions electrons spin-Peierls same Fe compound only transition occurs as stacks already in ground state.
The compounds [Hpy]2[{M(mnt)2}2][M = Fe or Co, Hpy pyridinium, mnt maleonitriledithiolate (2,3-disulfanylmaleonitrile)] have been prepared by electrocrystallization and characterized single-crystal X-ray diffraction, magnetic susceptibility measurements IR 57Fe Mössbauer spectroscopies. are isostructural, monoclinic, space group P21/n with Z= 2. They both consist in alternate packing of [{M(mnt)2}2]2– units, the metal a square-pyramidal environment co-ordinated sulfur atoms, pyridinium...
The nickel complex nBu4N[Ni(α-tpdt)2] (2) (α-tpdt = 2,3-thiophenedithiolate) has been prepared and characterized. A salt of this monoanionic paramagnetic complex, [Fe(Cp*)2][Ni(α-tpdt)2] (3), was obtained with decamethylferrocene, crystallizing in the monoclinic space group P21/a a 15.443(3), b 10.237(1), c 20.360(2) Å, β 107.54(1)°, V 3069.1(7) Å3, Z 4. Its structure consists alternating cationic anionic layers, short interlayer contacts defining cation−anion chains. Magnetic...
The electrocrystallization from dichloromethane or tetrahydrofuran solutions of the dissymmetrical bis(ethylenedithio)tetrathiafulvalene (ET) derivative cyanobenzene–ethylenedithio–tetrathiafulvalene (CNB-EDT-TTF) in presence perchlorate anion ClO4– affords two different polymorphs salts with 4:1 stoichiometry, a previously described triclinic phase β″T-(CNB-EDT-TTF)4ClO4 (1a), and new monoclinic β″M-(CNB-EDT-TTF)4ClO4, (1b), as well compound 1:1 (CNB-EDT-TTF)ClO4 (2), depending on solvent...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMagnetic properties of the low-dimensional systems (Per)2M(mnt)2 (M = Cu and Ni)V. da Gama, R. T. Henriques, M. Almeida, L. AlcacerCite this: J. Phys. Chem. 1994, 98, 3, 997–1001Publication Date (Print):January 1, 1994Publication History Published online1 May 2002Published inissue 1 January 1994https://pubs.acs.org/doi/10.1021/j100054a041https://doi.org/10.1021/j100054a041research-articleACS PublicationsRequest reuse permissionsArticle...
New electron-transfer salts, [M(Cp*)2][Ni(edt)2], with M = Fe and Cr, were prepared shown to be isostructural by X-ray crystallographic studies. The molecular structure of [Ni(edt)2]− is reported here for the first time. solid-state consists an array parallel alternating donors, [Fe(Cp*)2]•+, acceptors, [Ni(edt)2]•−, ··DADADA·· stacks along [101]. At high temperatures (T > 50−100 K), magnetic susceptibility obeys Curie−Weiss expression, θ values −5 −6.7 K Ni Cr compounds respectively,...
The new compound [Co(η5-C5H5)(dppf-P,P′)I]I, 1, was synthesised by the stoichiometric reaction of Co(III) complex [Co(η5-C5H5)(CO)I2], 2, with 1,1′-bis(diphenylphosphino)ferrocene (dppf) in CH2Cl2, and characterised multinuclear NMR spectroscopy. Exposure to air THF or CH2Cl2 solutions 1 gave, an unexpected way, a polymeric chain comprising bridging 1,1′-bis(oxodiphenylphosphoranyl)ferrocene (dppfO2) joining tetrahedral Co(II) units [CoI2(μ-dppfO2)]n, 3. Attempts obtain 3 direct dppfO2 CoI2,...
Abstract The family of charge‐transfer (CT) salts [M(Cp*) 2 ][Ni(α‐tpdt) ] [α‐tpdt = 2,3‐thiophenedithiolate; M Fe ( 1 ), Mn Cr 3 )] were prepared. crystal structure is similar to that previously reported for and composed alternatinglayers each consisting parallel mixed donor–acceptorD + A – D chains, the chains in adjacent layers are perpendicular. expected occur . McConnell I model was used analyze intermolecular magnetic coupling this compounds. predicted ferromagnetic (FM) intrachain...
Three new salts RBzPy+[Ni(α-tpdt)2]− (α-tpdt = 2,3-thiophenedithiolate, BzPy benzylpyridine, R H, Br, F) were prepared and structurally magnetically characterized. A common structural feature of these compounds is the arrangement anions with thiophenic sulfur atoms connecting to a coordinating atom neighbouring anion, placed almost perpendicular each other. The cations are positioned pyridine rings inserted between anions, maximizing π–π interactions. Depending on cation substitution...