The effect of solvent polarity on solubility of HMX and FOX-7: a DFT study

Production of micro and submicron-sized particles with a narrow particle size distribution (PSD) is gaining interests in materials technology especially in specialty chemicals. There are many conventional methods for the size reduction of particles such as milling, grinding, crushing, spray drying, and recrystallization from liquid solutions. A new, promising process for particulation of materials employs environmentally benign compressed gases as either solvents or anti-solvents. The molecular geometry of HMX and FOX-7 has been calculated by using the density functional method (B3LYP) invoking 6-311++G(d,p) basis set. The solvent effect was treated using a continuum model as modeled in hexane, benzene, chloroform, tetrahydrofurane, acetone, ethanol, methanol, dimethylformamide, acetonitrile and DMSO. Furthermore, dipole moment (D), polarizability (α), molecular electrostatic potential map (MEP), thermodynamic, frontier molecular orbital analysis (HOMO – LUMO), hardness (η), electronic chemical potential (µ), global electrophilicity index (ω) and ΔGsolv properties for HMX and FOX-7 in several solvents have been investigated and discussed. It is found that with an increasing solvent dielectric constant, the dipole moment of the molecules under study also increases. (author)