Provided technical assistance on data collection instrument for national survey for federal governmental agency

Provided computational support to research projects focused on antivirals and antibiotics Goal: Antiviral agents for Respiratory Syncytial Virus (RSV):Employed Ligand-Base Drug Design (LBDD) tools such as molecular overlays and 3D-similarity measurements to incorporate SAR features from published cross-resistant compound series into our own underdevelopment compounds.Goal: Penicillin Binding Proteins Inhibitors (PBPIs) for Pseudomonas aeruginosa (Pae):Applied chemical kinetics and Structure-Based Drug Design (SBDD) tools to show that, for a given (PBPI) family, the acylation rate is controlled by the stability of the pre-reaction complex. Used Docking to prioritize compound synthesis.Goal: De novo design of novel PBPIs for Pae:Used Density Functional Theory (DFT) calculations on model acylation reactions of known PBPI scaffolds to define rules for potential new warheads. Used molecular overlays of novel and known scaffolds to identify the best vectors for functionalization. Polished compound designs through Docking on co-crystal structures.

Carried out computational quantum chemistry studies to unveil reaction mechanisms and support experimental efforts in organometallic catalysis processes; Collaborated with scientists from the NSF Center for Selective C-H Functionalization Goal: Theoretical proposal of novel C-H functionalization catalysts based on cheaper earth-abundant metals:Predicted that (PDI)Fe(Cl)(OMe2) should be a good catalyst for the studied benzylic CH functionalization.Predicted that the metallic center remains Fe(II) all throughout the course of the reaction.Used DFT methods to assess (PDI)Ca(thf)3 as C-H functionalization catalysts.Concluded that the combination of a noninnocent ligand and a redox inert metal can potentially perform C-H functionalizations.Goal: DFT studies of the mechanisms of a Ir(III)-, Rh2(II,II)- and Ru2(II,II)-catalyzed CH functionalizations:Explained the Ir(III)-phebox enantioselectivity based on the active species formation mechanism.Studied the allylic amination vs. aziridination competition as catalyzed by Rh- and Ru-paddle wheel catalysts.Studied the tertiary vs. benzylic amination competition as catalyzed by Rh- and Ru-paddle wheel catalysts.Goal: Study the mechanism of an aerobic Cu(I)-catalyzed cross-coupling reaction between thiol esters and boronic acids:A dicationic complex based on a Cu2O2-core was proposed as active species.Analyzed the active species considering several isomers based on three different Cu2O2-cores: side-on peroxo, end-on peroxo and bis(-oxo).Proved that the proposed active species is able to catalyze the formation of the main cross-coupling product.Goal: Study the PCET mechanisms of water oxidation catalyzed by a fully-inorganic Ru4-POM2 catalyst:Predicted that [Ru4(O)4(OH)2(OH2)4(POM)2]10- but not [Ru4(O)6(OH2)4(POM)2]12- can catalyze the water oxidation reaction.

Conducted computational studies on solid-state polymers, organic and organometallic catalysis in solution, and gas-phase small molecule reactionsGoal: Investigate the proposed mechanism for doping of PANI with HCl:Used 1D and 2D Periodic Boundary Conditions DFT calculations to compute several phases of this polymer.Proved that counterions, interchain interactions and different unit cell sizes have to be considered to find the most stable phase.Goal: Study the mechanisms of different process belonging to the New Sulfur Dioxide Chemistry:Applied a synergetic approach between experimental and theoretical work.Elucidated the mechanism of the isomerization of alkenes double bonds mediated by sulfonyl radicals.Elucidated the mechanism of the retro-Ene reaction of unsaturated sulfinic acids.Predicted the first general Ene-reaction protocol between SO2 and unfunctionalized alkenes.Goal: Study the mechanism of isomerization of allylic alcohols into carbonyl compounds catalyzed by Ru(IV) organometallic compounds:Synergy between experimental and theoretical work.Elucidated the mechanism for conversion of precatalyst into catalyst.Obtained the catalytic cycles associated with the different experimental conditions employed.Predicted that water catalyzes the process in organic medium.Extended the isomerization to allylic esters based on the theoretical mechanism.

Goal: Assessment of the DFT and RASPT2 methodologies to study [CuO(NH3)x]2 (x: 0-3) complexes:Studied the triplet potential energy surface.Applied DFT methods to the four [CuO(NH3)x]2 (x: 0-3) systems and RASSCF methods to the [CuO]2 system.Computed CR-CCSD(2,3) reference values for the two [CuO(NH3)x]2 (x: 0-1) systems.

Goal: Gas-phase kinetic study of the C-F bond activation of fluoromethane with a variety of metallic monocations:Wrote a code for RRKM calculations to study these reactions at the low pressure limit (collisionless regime). Showed that both the tight and the loose transition-state (entrance channel) structures have to be considered to produce accurate kinetic constants.

Goal: Analysis of the metal-ligand bond in [M(E4)2] (M: Ni, Pd, Pt; E: CH, N, P, As, Sb, Bi) sandwich compounds:Concluded that Metal-Ligand bonds are more electrostatic than covalent, except for the [M(N4)2] (M = Ni-Pt) complexesEstimated that pi-bonding back-donation from the metal to the ligands is the main contribution to the covalent bonding

Goal: Kinetic studies of the degradation of HFCs by OH radical attack:Used VTST/MT to obtain highly accurate rate constants and assess the tunneling contribution.Assessed DeMore’s and Tokuhashi’s QSARs performances based on the calculated kinetic constants.