A DFT and TDDFT investigation of interactions between 1-hydroxypyrene and aromatic amino acids

WOS: 000364611600002This study presents a computational investigation of formation photoinduced charge transfer complexes between 1-hydroxypyrene (PyOH) and aromatic amino acids (Phenylalanine: Phe, Tyrosine: Tyr, Tryptophan: Trp) in gas phase and in water. Geometry optimizations were performed by density functional theory (DFT) at omega B97XD/6-31 1++G(d,p) level. Time-dependent density functional theory (TDDFT) was used to calculate the electronic transitions of molecules at B3INP/6-311++G(d,p) and CAM-B3LYP/6-311++G(d,p) levels using the ground-state geometries from omega B97XD/6-311++G(d,p). Polarizable Continuum Model (PCM) is used for calculations in water. Total electronic energies, complexation energies, free energy differences, solvation energies, excitation wavelengths, and HOMO-LUMO energy gaps of complexes have been analyzed and compared in gas phase and in solution. The intermolecular distances between PyOH and amino acids increased in water compared to the gas phase. The optimized complexes display an increasing complex stability in the order Trp > Tyr > Phe. Analyses of first excited singlet states have revealed that there are charge transfers between PyOH and amino acids through pi-pi stacking except PyOH-Phe complexes in both media. The charge distributions increased in water. Among all studied systems, PyOH-Trp systems have the most significant charge transfer between HOMO-1 and LUMO (full CT, 59%). However, dipole moment and oscillator strength of this transition (S-0-S-1) are weaker compared to the other studied systems. PyOH-Trp systems are determined to be the best model to investigate and design bioorganic photosensitive materials with its charge transfer character. (C) 2015 Elsevier B.V. All rights reserved.Ege UniversityEge University [2012 FEN 051]The authors gratefully acknowledge Ege University for financial support of this research work (BAP Project No: 2012 FEN 051)

Upper crustal electrical resistivity structures in the vicinity of the Catalca Fault, Istanbul, Turkey by magnetotelluric data

A magnetotelluric survey was performed at the Catalca Region, west of Istanbul, Turkey with the aim of investigating geoelectrical properties of the upper crust near the Catalca Fault and its vicinity. Broadband magnetotelluric data were collected at nine sites along a single southwest-northeast profile to image the electrical resistivity structure from surface to the 5 km depth. The dimensionality of the data was examined through tensor decompositions and highly two-dimensional behavior of the data is shown. Following the tensor decompositions, two-dimensional inversions were carried out where E-polarization, B-polarization and tipper data were utilized to construct electrical resistivity models. The results of the inversions suggest: a) the Catalca Fault extends from surface to 5 km depth as a conductive zone dipping to southwest; b) the thickness of the sedimentary cover is increasing from SW to NE to 700 m with low resistivity values between 1-100 Omega m; c) the crystalline basement below the sedimentary unit is very resistive and varies between 2000-100000 Omega m; d) a SW-dipping resistivity boundary in the northeastern part of our profile may represent the West Black Sea Fault