Eduardo A. Castro

Prediction of electron affinities from fundamental theorems involving the electron density, , and the Z -1 perturbation expansión (2010)

Eduardo A. Castro; INIFTA, Francisco M. Fernández; INIFTA

The electrón affinities of the elementa H through F have been obtained wlthin the frameworlt of fundamental theorems Involving the electrón denslty, , and the Z-1 perturt>ation expansión. The...

Una técnica omega biparamétrica mejorada para cálculos con orbitales moleculares (2010)

Dora J. Baibiric; INIFTA, Eduardo A. Castro; INIFTA, Francisco M. Fernández; INIFTA

Se han calculado los momentos dipolares de algunos hidrocarburos bo-bencenoldes por medio de una técnica omega biparamétrica mejorada. Los resultados obtenidos son mejores que aquéllos calculados...

An improved two-parameter omega technique (ITPOT) for molecular orbital calculatlons (2010)

Dora J. Barbiric; INIFTA, Eduardo A. Castro; INIFTA, Francisco M. Fernández; INIFTA

Bond lengths are calculated for tweive aromatic hydrocarbons by way of the ITPOT and a modified Coulson's equatlon. Comparlsons are made with respect to other theoretlcal results as well as with...

Una formulación rigurosa del método varacional (2009)

Eduardo A. Castro; INIFTA, Fracisco M. Fernández; INIFTA

Se presentan de un modo riguroso y ordenado los fundamentos del Método variacional y algunas de sus principales consecuencias, prestando particular atención a aquellos aspectos menos difundidos del...

Some numerlcai analysis of the omega technique (2009)

Doris J. Barbiric; INIFTA, Eduardo A. Castro; INIFTA, Francisco M. Fernández; INIFTA

Se llevaron a cabo verificaciones numéricas de las ecuaciones deducidas por goodlsman para las desviaciones de las poblaciones de los orbitales atómicos y las energías de los orbitales moleculares...

Una formulación rigurosa del método varacional (2009)

Eduardo A. Castro; INIFTA, Fracisco M. Fernández; INIFTA

Se presentan de un modo riguroso y ordenado los fundamentos del Método variacional y algunas de sus principales consecuencias, prestando particular atención a aquellos aspectos menos difundidos del...

Some numerlcai analysis of the omega technique (2009)

Doris J. Barbiric; INIFTA, Eduardo A. Castro; INIFTA, Francisco M. Fernández; INIFTA

Se llevaron a cabo verificaciones numéricas de las ecuaciones deducidas por goodlsman para las desviaciones de las poblaciones de los orbitales atómicos y las energías de los orbitales moleculares...

Spin Polarized Density Functional Theory Applied to the Study of Nanoalloys (2009)

Erlinda Del V. Ortiz; Centro De Investigaciones Fisicoquímicas, Teóricas Y Aplicadas (CIFTA), Facultad De Ciencias Exactas Y Naturales, Universidad Nacional De Catamarca, María B. López; Centro De Investigaciones Fisicoquímicas, Teóricas Y Aplicadas (CIFTA), Facultad De Ciencias Exactas Y Naturales, Universidad Nacional De Catamarca, Eduardo A. Castro; Instituto De Investigaciones Físicoquímicas Teóricas Y Aplicadas, CONICET, Universidad Nacional De La Plata

The electronic properties and reactivity of Ag Pt. (1 ≤ x ≤ 10) nanoalloys were investigated by spin polarized calculations within the framework of density-functional theory (SP-DFT). Both the...

QSPR Studies on Aqueous Solubilities of Drug-Like Compounds (2009)

Pablo R. Duchowicz, Eduardo A. Castro

A rapidly growing area of modern pharmaceutical research is the prediction of aqueous solubility of drug-sized compounds from their molecular structures. There exist many different reasons for...

Chemical Topology of Crystalline Matter and the Transcendental Numbers ϕ , e and π (2008)

Michael J. Bucknum, Eduardo A. Castro

This work is intended as a review and extension of the seminal work in chemical topology developed by the crystallographer A.F. Wells in the 20th century.

Tautomeric Equilibria Studies by Mass Spectrometry (2008)

Patricia E. Allegretti, Mercedes M. Schiavonni, Eduardo A. Castro, Jorge J. Furlong

Tautomerism in organic chemistry has been extensively studied in condensed phase by spectrometric methods, mainly by IR and NMR techniques. Mass spectrometry studies start 40 years ago but just...

Geometrical-topological correlation in structures (2008)

Michael J. Bucknum, Eduardo A. Castro

The topology of polyhedra, tessellations and networks is described as to their mapping in Schlaefli space. A description of the topological form index is given and it is applied to these structural...

Chemical physics: The standing of a mature discipline (2007)

Castro, Eduardo A

Abstract It is always promising and enticing to start a new editorial task in the scientific arena and the launch of the Chemistry Central Journal is no exception. The different thematic sections...

Jubilite: A 4-,8-connected Cubic Structural Pattern in Space Group Pm3 (2005)

Michael J. Bucknum, Eduardo A. Castro

Abstract: In the course of investigating structural modifications of the 3-,4-connected net known as the Pt3O4 structure-type (waserite), a novel 4-,8-connected structure-type was discovered. This...

QSPR Calculation of Normal Boiling Points of Organic Molecules Based on the Use of Correlation Weighting of Atomic Orbitals with Extended Connectivity of Zero- and First-Order Graphs of Atomic Orbitals (2004)

Maykel Pérez González, Andrey A. Toropov, Pablo R. Duchowicz, Eduardo A. Castro

We report the results of a calculation of the normal boiling points of a representative set of 200 organic molecules through the application of QSPR theory. For this purpose we have used a particular...

Atom, Atom-Type, and Total Linear Indices of the “Molecular Pseudograph’s Atom Adjacency Matrix”: Application to QSPR/QSAR Studies of Organic Compounds (2004)

Yovani Marrero Ponce, Juan Alberto Castillo Garit, Francisco Torrens, Vicente Romero Zaldivar, Eduardo A. Castro

In this paper we describe the application in QSPR/QSAR studies of a newgroup of molecular descriptors: atom, atom-type and total linear indices of the molecularpseudograph’s atom...

Protein Quadratic Indices of the “Macromolecular Pseudograph’s α-Carbon Atom Adjacency Matrix”. 1. Prediction of Arc Repressor Alanine-mutant’s Stability (2004)

Yovani Marrero Ponce, Ricardo Medina Marrero, Eduardo A. Castro, Ronal Ramos De Armas, Humberto González Díaz, Vicente Romero Zaldivar, ...

This report describes a new set of macromolecular descriptors of relevance toprotein QSAR/QSPR studies, protein’s quadratic indices. These descriptors are calculatedfrom the...

Nucleic Acid Quadratic Indices of the “Macromolecular Graph’s Nucleotides Adjacency Matrix”. Modeling of Footprints after the Interaction of Paromomycin with the HIV-1 Ψ-RNA Packaging Region (2004)

Yovani Marrero Ponce, Delvin Nodarse, Humberto González Díaz, Ronal Ramos De Armas, Vicente Romero Zaldivar, Francisco Torrens, ...

This report describes a new set of macromolecular descriptors of relevance to nucleic acid QSAR/QSPR studies, nucleic acids’ quadratic indices. These descriptors are calculated from the...

Enol and Enethiol Occurrence for Some Ketones and Thioketones. Mass Spectrometry and Theoretical Calculations (2004)

Patricia E. Allegretti, María De Las Mercedes Schiavoni, María Susana Cortizo, Eduardo A. Castro, Jorge J. P. Furlong

Abstract: The mass spectra of ketones can provide valuable information with regards to keto-enol equilibria occurring in the gas phase. Mass spectra of selected ketones and thioketones have been...

Semiempirical Calculation of the Reaction Products Arising from the Complexation of the Trimeric o-tetrafluorophenylene Mercury with Benzene (2004)

Eduardo A. Castro

A semi-empirical calculation of the titled compounds is made at the AM1 molecular orbital method level. Structural and bonding features are analyzed and results are compared with previous...

Semiempirical Calculation of the Reaction Products Arising from the Complexation of the Trimeric o-tetrafluorophenylene Mercury with Benzene (2004)

Eduardo A. Castro

A semi-empirical calculation of the titled compounds is made at the AM1 molecular orbital method level. Structural and bonding features are analyzed and results are compared with previous...

Nucleic Acid Quadratic Indices of the “Macromolecular Graph’s Nucleotides Adjacency Matrix”. Modeling of Footprints after the Interaction of Paromomycin with the HIV-1 Ψ-RNA Packaging Region (2004)

Yovani Marrero Ponce, Delvin Nodarse, Humberto González Díaz, Ronal Ramos De Armas, Vicente Romero Zaldivar, Francisco Torrens, ...

Abstract: This report describes a new set of macromolecular descriptors of relevance to nucleic acid QSAR/QSPR studies, nucleic acids ’ quadratic indices. These descriptors are calculated from the...

QSPR Modeling of Lipophilicity by Means of Correlation Weights of Local Graph Invariants (2003)

Pablo J. Peruzzo, Damian J. G. Marino, Eduardo A. Castro, Andrey A. Toropov

A quantitative structure-property modeling of the log P (octanol/water partition coefficient) of 76 industrial chemicals is presented. Estimations are performed by means of correlation weighting of...

Theoretical Study on the Interaction of o-Tetrafluorophenylene Mercury with Ethylene and Acetylene (2003)

Eduardo A. Castro

The results of a theoretical study on the interaction of o-tetrafluorophenylene mercury with ethylene and acetylene are reported. The AM1 molecular orbital semiempirical method is applied through a...

Structure–Toxicity Relationships for Aliphatic Compounds Based on Correlation Weighting of Local Graph Invariants (2003)

Andrey A. Toropov, Pablo Duchowicz, Eduardo A. Castro

Quantitative Structure-Activity Relationships based on molecular descriptors calculated with Correlation Weights of Local Graph Invariants were developed to model the toxicity of aliphatic compounds...

QSAR Carcinogenic Study of Methylated Polycyclic Aromatic Hydrocarbons Based on Topological Descriptors Derived from Distance Matrices and Correlation Weights of Local Graph Invariants (2002)

Damian J. G. Marino, Pablo J. Peruzzo, Eduardo A. Castro, Andrey A. Toropov

A quantitative structure-activity study for the carcinogenic activity of methylated polycyclic aromatic hydrocarbons is made on the basis of topological molecular descriptors derived from distance...

Upgrading the Wiener index (2002)

EDUARDO A. CASTRO, IVAN GUTMAN, DAMIAN MARINO, PABLO PERUZZO

The Wiener index W is the oldest molecular-graph-based structure-descriptor. It is defined as the sum of the distances of all pairs of vertices of the molecular graph G, where the distance is the...

Improved Molecular Descriptors Based on the Optimization of Correlation Weights of Local Graph Invariants (2001)

Germán Krenkel, Eduardo A. Castro, Andrey A. Toropov

We report the calculation of boiling points for several alkyl alcohols through the use of improved molecular descriptors based on the optimization of correlation weights of local invariants of...

Maximum Topological Distances Based Indices as Molecular Descriptors for QSPR. 4. Modeling the Enthalpy of Formation of Hydrocarbons from Elements (2001)

Andrés Mercader, Eduardo A. Castro, Andrey A. Toropov

The enthalpy of formation of a set of 60 hydroarbons is calculated on the basis of topological descriptors defined from the distance and detour matrices within the realm of the QSAR/QSPR theory....

Chemical physics: The standing of a mature discipline

Castro, Eduardo A

It is always promising and enticing to start a new editorial task in the scientific arena and the launch of the Chemistry Central Journal is no exception. The different thematic sections making up...

QSPR Studies on Aqueous Solubilities of Drug-Like Compounds

Duchowicz, Pablo R., Castro, Eduardo A.

A rapidly growing area of modern pharmaceutical research is the prediction of aqueous solubility of drug-sized compounds from their molecular structures. There exist many different reasons for...