The atomic coordinates obtained with the PM6 and PM7 methods are stored in files ending in ".xyz", one for each molecule. The format is the standard MDL SDFile generated with ChemAxon Standardizer and OpenBabel. These are the starting structures, previous to geometry relaxation with the MOPAC program. Structures were calculated with the geometry obtained with the PM6 or PM7 semi-empirical method.Įach molecule is stored in its own file, ending in ".sdf". Molecular geometries were relaxed by the PM6 or PM7 methods using the MOPAC software and orbital energies were calculated by the GAMESS program with the B3LYP functional and the 6-31G* basis set. The molecular structures include atomic elements C, H, B, N, O, F, Si, P, S, Cl, Se, and Br. The structures were standardized with ChemAxon Standardizer (JChem 15.4.6, 2015, ChemAxon, ) and OpenBabel (Open Babel Package, version 2.3.1 ) for neutralization and inclusion of all hydrogen atoms. The database was populated by retrieval of similar examples from the ZINC database, the PubChem database and by computationally combining motifs and lists of substituents with the ChemAxon Reactor software, JChem 15.4.6, 2015, ChemAxon (). PM7_frontier_orbitals.xlsx - HOMO and LUMO energies calculated by the PM7 semi-empirical method.įor the database creation, molecular structural motifs were retrieved from organic electronics studies, and collections of dyes, metabolites and electrophiles/nucleophiles. Machine Learning Methods to Predict Density Functional Theory B3LYP Energies of HOMO and LUMO Orbitals.įrontier_orbitals_111725mols_ - 111275 molecules in the MDL SDFile formatįrontier_orbitals_111725mols.xlsx - HOMO and LUMO orbital energies for 111275 neutral organic moleculesĬoordinates_111725mols_xyz.zip - atomic coordinates used for the DFT calculation of the 111275 molecules Latino, Chengcheng Wu, Qingyou Zhang and Joao Aires-de-Sousa: * Florbela Pereira, Kaixia Xiao, Diogo A. Copyright © 2011 John Wiley & Sons, Ltd.HOMO and LUMO orbital energies for 111725 organic molecules calculated at the B3LYP/6-31G*//PM6 or B3LYP/6-31G*//PM7 level of theory. These trends may provide insight into developing materials with specifically tuned HLGs and HOMO–LUMO levels for a variety of applications. The data presented not only elaborate on the HOMO–LUMO tuning of 9-fluorenone systems but also enable the consideration of 9-fluorenones as analogous models for HOMO–LUMO tuning in other more complex polyaromatic systems such as bifluorenylidenes. Spectroscopic evidence of substituent influence on the carbonyl suggests that substituents directly impact the HLG by influencing the availability of nonbonding electrons within the carbonyl, which impacts the probability of an nπ* transition.
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Increasing conjugation decreased the HLG, increased the HOMO energy level, but decreased the LUMO energy level. Increasing the electron-donating character of the substituents was observed to decrease the HLG and increase the energy levels of the HOMO and the LUMO, whereas an increase in the electron-withdrawing character produced the opposite results. Results from both methods were compared and correlated with the differences in molecular structure. Electrochemical and optical measurements were used to calculate the HOMO–LUMO levels and HOMO–LUMO bandgap (HLG) for each structure. Compounds with an incremental increase in conjugation were also examined. Trends were explored in a range of compounds, beginning with structures having highly electron-withdrawing substituents and progressing to structures having highly electron-donating substituents. A study of the specific effects and overall trends for the HOMO–LUMO tuning of a diverse series of 9-fluorenones by means of extended conjugation and substituent effects is described. Highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) tuning is an important consideration in the development of organic-based semiconducting materials.