Computational Data for UV–Vis Absorption, Photolysis Thresholds, OH-Initiated Radical Formation, and Radical-Initiated Fragmentation in C5H12O6 Isoprene-Derived Oxidation Products

This dataset contains the computational data supporting the manuscript: "Computational Study of UV–Vis Absorption, Photolysis Thresholds, OH-Initiated Radical Formation, and Radical-Initiated Fragmentation in C5H12O6 Isoprene-Derived Oxidation Products." The dataset comprises Gaussian input and output files, optimized molecular geometries, transition-state structures, intrinsic reaction coordinate (IRC) calculations, TD-DFT excited-state calculations, natural transition orbital (NTO) analyses, charge-transfer diagnostics, bond dissociation energies, thermodynamic data, and transition-state theory (TST) kinetic calculations. The study investigates the electronic structure, UV–vis absorption properties, photolysis-relevant bond dissociation pathways, OH•-initiated hydrogen-atom abstraction (HAA), H•-induced O–H stripping reactions, oxygen-centered alkoxyl radical formation, and subsequent α C–C scission fragmentation pathways of C5H12O6, a highly oxygenated isoprene-derived secondary organic aerosol (SOA) constituent. Computational methods include: Geometry optimizations and frequency calculations at the M06-2X/def2-TZVP level of theory. Single-point energy calculations at the B3LYP-D3(BJ)/6-311+G(3df,3pd) level. TD-DFT calculations using CAM-B3LYP/6-311++G(3df,3pd). Implicit solvation using gas-phase, SMD MeCN, SMD water, and a custom SOA-like dielectric medium. Natural Bond Orbital (NBO), spin-density, and charge-transfer analyses. The data establish a mechanistic framework linking electronic excitation accessibility, radical formation, alkoxyl radical stability, low-barrier α-scission fragmentation, and volatility-altering degradation pathways relevant to the atmospheric aging of highly oxygenated isoprene-derived SOA constituents. Associated manuscript: Submitted to the Journal of Computational Chemistry (2026).