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Full-Text Articles in Physical Sciences and Mathematics
Electronic Structure And Bonding In Metal Porphyrins, Metal=Fe, Co, Ni, Cu, Zn, M.-S. Liao, Steve Scheiner
Electronic Structure And Bonding In Metal Porphyrins, Metal=Fe, Co, Ni, Cu, Zn, M.-S. Liao, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
A systematic theoretical study of the electronic structure and bonding in metal meso-tetraphenyl porphines MTPP, M=Fe, Co, Ni, Cu, Zn has been carried out using a density functional theory method. The calculations provide a clear elucidation of the ground states for the MTPPs and for a series of [MTPP]x ions (x = 2+, 1+, 1−, 2−, 3−, 4−), which aids in understanding a number of observed electronic properties. The calculation supports the experimental assignment of unligated FeTPP as 3A2g, which arises from the configuration (dxy)2(dz …
Electronic Structure And Bonding In Unligated And Ligated Feii Porphyrins, M.-S. Liao, Steve Scheiner
Electronic Structure And Bonding In Unligated And Ligated Feii Porphyrins, M.-S. Liao, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
The electronic structure and bonding in a series of unligated and ligated FeII porphyrins (FeP) are investigated by density functional theory (DFT). All the unligated four-coordinate iron porphyrins have a 3A2g ground state that arises from the (dxy)2(dz2)2(dπ)2 configuration. The calculations confirm experimental results on Fe tetraphenylporphine but do not support the resonance Raman assignment of Fe octaethylporphine as 3Eg, nor the early assignment of Fe octamethyltetrabenzporphine as 5B2g. For the six-coordinate Fe–P( …
Electronic Structure And Bonding In Metal Phthalocyanines, Metal=Fe, Co, Ni, Cu, Zn, Mg, M.-S. Liao, Steve Scheiner
Electronic Structure And Bonding In Metal Phthalocyanines, Metal=Fe, Co, Ni, Cu, Zn, Mg, M.-S. Liao, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Electronic structure and bonding in metal phthalocyanines (Metal=Fe, Co, Ni, Cu, Zn, Mg) is investigated in detail using a density functional method. The metal atoms are strongly bound to the phthalocyanine ring in each case, by as much as 10 eV. The calculated orbital energy levels and relative total energies of these D4h structures indicate that Fe and Co phthalocyanines have 3A2g and 2Eg ground states, respectively, but that these states are changed upon interaction with strong-field axial ligands. The valence electronic structures of Fe and Co phthalocyanines differ significantly from those of …
Characterization Of Ground And Excited Electronic State Deprotonation Energies Of Systems Containing Double Bonds Using Natural Bond Orbital Analysis, J. K. Badenhoop, Steve Scheiner
Characterization Of Ground And Excited Electronic State Deprotonation Energies Of Systems Containing Double Bonds Using Natural Bond Orbital Analysis, J. K. Badenhoop, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Natural bond orbital analysis is applied to the ground and excited states of a set of neutral, cationic, and anionic doubly bonded species HnC=XHn (X=C, N, O) isoelectronic with ethylene. The character of the excitation is correlated with calculated charge shifts and geometry changes upon relaxation. For these planar molecules, depopulation of the π bond or population of the π∗ antibond causes an out‐of‐plane twist or pyramidalization upon relaxation correlated to the amount of charge shift. These nonplanar distortions generally lower the energy more than changes in bond lengths and angles. Population of a σXH∗ …
Proton Transfers In Hydrogen‐Bonded Systems. Vi. Electronic Redistributions In (N2h7)+ And (O2h5)+, Steve Scheiner
Proton Transfers In Hydrogen‐Bonded Systems. Vi. Electronic Redistributions In (N2h7)+ And (O2h5)+, Steve Scheiner
Chemistry and Biochemistry Faculty Publications
Electronic rearrangements accompanying transfer of the central proton between the two XHn units of (H3NHNH3)+ and (H2OHOH2)+ are studied using ab initio molecular orbital methods. Electron density difference maps are calculated by subtracting the density of the equilibrium structure (X–H‐‐‐X) from that of the midpoint geometry (X‐‐H‐‐X) using the split‐valence 4‐31G basis set. Some of the features revealed by the maps are common to both systems while others indicate significant differences between nitrogen and oxygen. Decomposition of the total electron density into …