Javier Tercero

Bio: Javier Tercero is an academic researcher from University of Barcelona. The author has contributed to research in topics: Homoleptic & Schiff base. The author has an hindex of 21, co-authored 37 publications receiving 1205 citations. Previous affiliations of Javier Tercero include Catalan Institution for Research and Advanced Studies & University of Santiago de Compostela.

Dinuclear Complexes of MII Thiocyanate (M = Ni and Cu) Containing a Tridentate Schiff‐Base Ligand: Synthesis, Structural Diversity and Magnetic Properties

Abstract: A dinuclear Ni-II complex, [Ni-2(L)(2)(H2O)(NCS)(2)]center dot 3H(2)O (1) in which the metal atoms are bridged by one water molecule and two mu(2)-phenolate ions, and a thiocyanato-bridged dimeric Cull complex, [Cu(L)NCS](2) (2) [L = tridentate Schiff-base ligand, N-(3-aminopropyl)salicylaldimine, derived from 1:1 condensation of salicylaldehyde and 1,3-diaminopropane], have been synthesized and characterized by IR and UV/Vis spectroscopy, cyclic voltammetry and single-crystal X-ray diffraction studies. The structure of 1 consists of dinuclear units with crystallographic C-2 symmetry in which each Ni-II atom is in a distorted octahedral environment. The Ni-O distance and the Ni-O-Ni angle, through the bridged water molecule, are 2.240(11) angstrom and 82.5(5)degrees, respectively. The structure of 2 consists of dinuclear units bridged asymmetrically by di-mu(1,3)-NCS ions; each Cull ion is in a square-pyramidal environment with tau = 0.25. Variable-temperature magnetic susceptibility studies indicate the presence of dominant ferromagnetic exchange coupling in complex 1 with J = 3.1 cm(-1), whereas complex 2 exhibits weak antiferromagnetic coupling between the Cu-II centers with J = -1.7 cm(-1). ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Exchange coupling in transition-metal complexes via density-functional theory: comparison and reliability of different basis set approaches.

Abstract: Theoretical methods based on density-functional theory with Gaussian, plane waves, and numerical basis sets were employed to evaluate the exchange coupling constants in transition-metal complexes. In the case of the numerical basis set, the effect of different computational parameters was tested. We analyzed whether and how the use of pseudopotentials affects the calculation of the exchange coupling constants. For the three different basis sets, a comparison of the exchange coupling constants and spin distributions shows that both the plane-wave and the numerical basis set approaches are accurate and reliable alternatives to the more established Gaussian basis functions.

Density functional study of magnetostructural correlations in cubane complexes containing the Cu4O4 core

Abstract: A study of the magnetostructural correlations in polynuclear complexes containing a Cu4O4 cubane structure has been carried out employing theoretical calculations based on Density Functional Theory. We have analyzed independently the magnetic properties of three different families of cubane complexes, classified according to the number of short and long Cu⋯Cu distances as 2 + 4, 4 + 2 or 6 + 0. The results indicate that coupling through four short Cu–O bridges can be from weakly ferromagnetic to strongly antiferromagnetic, while that through two or three short bridges can be from moderately ferromagnetic to weakly antiferromagnetic.

Magnetic structure of the large-spin Mn10 and Mn19 complexes: a theoretical complement to an experimental milestone.

Abstract: High-spin molecules have been proposed as candidates for the storage of information at the molecular level. The electronic structure of two complex magnetic molecular systems, Mn10 and Mn19, is characterized by means of a computational study based on density functional theory. All the exchange interactions in the recently reported Mn19 complex with the highest known spin value of 83/2, and in its highly symmetric Mn10 parent compound, are ferromagnetic. In these complexes, there are two kinds of ferromagnetic coupling: the first one corresponds to MnII−MnIII interactions through a double μ2-alkoxo-μ4-oxo bridge where the high coordination number of the MnII cations results in long MnII−O bond distances, while the second one involves MnIII−MnIII interactions through μ2-alkoxo-μ3-η1:η1:η1 azido bridging ligands with long MnIII−N distances due to a Jahn−Teller effect.

Synthesis of Two New Linear Trinuclear CuII Complexes: Mechanism of Magnetic Coupling through Hybrid B3LYP Functional and CShM Studies

Abstract: Two new CuII linear trinuclear Schiff base complexes, [Cu3(L)2(CH3COO)2] (1) and [Cu3(L)2(CF3COO)2] (2), have been prepared using a symmetrical Schiff base ligand H2L [where H2L = N,N′-bis(2-hydroxyacetophenone)propylenediimine]. Both of the complexes have been characterized by elemental analyses, Fourier transform IR, UV/vis, and electron paramagnetic resonance spectroscopy. Single-crystal X-ray structures show that the adjacent CuII ions are linked by double phenoxo bridges and a μ2−η1:η1 carboxylato bridge. In each complex, the central copper atom is located in an inversion center with distorted octahedral coordination geometry, while the terminal copper atoms have square-pyramidal geometry. Cryomagnetic susceptibility measurements over a wide range of temperature exhibit a distinct antiferromagnetic interaction of J = −36.5 and −72.3 cm−1 for 1 and 2, respectively. Density functional theory calculations (B3LYP functional) and continuous-shape measurement (CShM) studies have been performed on the trinu...

Jaguar: A high-performance quantum chemistry software program with strengths in life and materials sciences

Abstract: Jaguar is an ab initio quantum chemical program that specializes in fast electronic structure predictions for molecular systems of medium and large size. Jaguar focuses on computational methods with reasonable computational scaling with the size of the system, such as density functional theory (DFT) and local second-order Moller–Plesset perturbation theory. The favorable scaling of the methods and the high efficiency of the program make it possible to conduct routine computations involving several thousand molecular orbitals. This performance is achieved through a utilization of the pseudospectral approximation and several levels of parallelization. The speed advantages are beneficial for applying Jaguar in biomolecular computational modeling. Additionally, owing to its superior wave function guess for transition-metal-containing systems, Jaguar finds applications in inorganic and bioinorganic chemistry. The emphasis on larger systems and transition metal elements paves the way toward developing Jaguar for its use in materials science modeling. The article describes the historical and new features of Jaguar, such as improved parallelization of many modules, innovations in ab initio pKa prediction, and new semiempirical corrections for nondynamic correlation errors in DFT. Jaguar applications in drug discovery, materials science, force field parameterization, and other areas of computational research are reviewed. Timing benchmarks and other results obtained from the most recent Jaguar code are provided. The article concludes with a discussion of challenges and directions for future development of the program. © 2013 Wiley Periodicals, Inc.

A Graphene Oxide and Copper-Centered Metal Organic Framework Composite as a Tri-Functional Catalyst for HER, OER, and ORR

Abstract: A composite made from the assembly of graphene oxide (GO) and copper-centered metal organic framework (MOF) shows good performance as a tri-functional catalyst in three important electrocatalysis reactions, namely: the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR). One of the challenges in the area of electrocatalysis is to find an effective catalyst that will reduce, as well as generate, oxygen at moderate temperatures. The enhanced electrocatalytic properties and stability in acid of the GO-MOF composite is due to the unqiue porous scaffold structure, improved charge transport and synergistic interactions between the GO and MOF. In polymer electrolyte membrane fuel cell testing, the GO-incorporated Cu-MOF composite delivers a power density that is 76% that of the commercial Pt catalyst.

Anaesthesia in the prone position

Abstract: Prone positioning of patients during anaesthesia is required to provide operative access for a wide variety of surgical procedures. It is associated with predictable changes in physiology but also with a number of complications, and safe use of the prone position requires an understanding of both issues. We have reviewed the development of the prone position and its variants and the physiological changes which occur on prone positioning. The complications associated with this position and the published techniques for various practical procedures in this position will be discussed. The aim of this review is to identify the risks associated with prone positioning and how these risks may be anticipated and minimized.