- Systematic Characterization of Gas Phase Binary Pre-Nucleation Complexes Containing H2SO4 + X, [X = NH3, (CH3)NH2, (CH3)(2)NH, (CH3)(3)N, H2O, (CH3)OH, (CH3)(2)O, HF, CH3F, PH3, (CH3)PH2, (CH3)(2)PH, (CH3)(3)P, H2S, (CH3)SH, (CH3)(2)S, HCI, (CH3)CI)]. A Computational Study