The electronic structure of iron phthalocyanine (FePc) in the valence region was examined within a joint theoretical-experimental collaboration. Particular emphasis was placed on the determination of the energy position of the Fe 3d levels in proximity of the highest occupied molecular orbital (HOMO). Photoelectron spectroscopy measurements were performed on FePc in gas phase at several photon ...

The relative ease of Mössbauer spectroscopy and of density functional theory (DFT) calculations encourages the use of Mössbauer parameters as a validation method for calculations, and the use of calculations as a double check on crystallographic structures. A number of studies have proposed correlations between the computationally determined electron density at the iron nucleus and the observed...

In the present work, the quantum theoretical calculations of the molecular structure of the 1-(1, 3-Benzothiazol-2-yl)-3-(thiophene-5-carbonyl) thiourea has been predicted and are evaluated using Density Functional Theory (DFT) in gas phase. The geometry of the title compound was optimized by B3LYP/6-311+G and B3LYP/6-311+G* methods and the experimental geometrical parameters of the title compo...

In the title inner salt molecule, C10H10N2O3, the four-membered cyclobutene ring is twisted by 7.1 (2)° with respect to the five-membered imidazole ring. The crystal packing exhibits an R 2 (2)(9) hydrogen-bonding ring motif through N-H⋯O and C-H⋯O inter-actions. The potential non-linear optical properties were studied by a computational ab initio calculations performed at the DFT/B3LYP/6-31++G...

Department of Chemistry, Thompson Rive Canada. E-mail: [email protected] Department of Chemistry, University of Gu † Electronic supplementary information ( the B3LYP functional and the IEF-PCM Calculated pKa values and their errors in 250 C/20 MPa using the B3LYP function method (Tables S2–S5, Fig. S1–S4). A Bor acid in light and heavy water (Fig. S5). pKa and errors in H2O and D2O (pKa(25 functiona...

The application domain of accurate and efficient CE-B3LYP and CE-HF model energies for intermolecular interactions in molecular crystals is extended by calibration against density functional results for 1794 molecule/ion pairs extracted from 171 crystal structures. The mean absolute deviation of CE-B3LYP model energies from DFT values is a modest 2.4 kJ mol-1 for pairwise energies that span a r...

In earlier studies (Gross and Seybold, Int J Quantum Chem, 2001, 85, 569; Gross et al., Int J Quantum Chem, 2002, 90, 445), it was shown that variations in several calculated quantum chemical charge and energy parameters were strongly correlated with the pKa variations in a set of substituted phenols. Here, we examine whether this approach can be extended to the pKas of a diverse set of more co...

Depending on the selected DFT functional, two different mechanisms are found for two organic reactions (an intramolecular nucleophilic aromatic substitution and a nucleophilic addition on a carbonyl moiety). Indeed, B3LYP predicts a concerted mechanism whereas M06-2X foresees a multistep one. Calculations at the MP4(SDQ) level proved the mechanisms to be stepwise. We studied these reactions wit...

A combined theoretical and experimental kinetic and mechanism of diallyl disulfide pyrolysis reaction in the gas phase was studied in a static system over the temperature range of 586.7–621.2 K and a total pressure of 72 Torr in the presence of cyclohexene as radicals inhibitor. The experimental results show that the reaction is homogeneous, unimolecular and proceeds through a radical mechanism...

We use a combination of Time-Dependent Density Functional Theory (TD-DFT) and approximate Coupled Cluster Theory (RI-CC2) to compare trends in the optical gap and fluorescence energies of ortho-, meta- and para-oligomers of phenylene. We find that RI-CC2 and TD-DFT calculations using three different commonly employed XC-potentials (B3LYP, BHLYP and CAM-B3LYP) generally give consistent predictio...