The mixed quantum-classical Liouville equation provides a unified and self-consistent platform for modeling the spectral signatures of nonequilibrium solvation dynamics, non-Condon effects, and nonadiabatic transitions. These features are demonstrated in this paper in the context of the pump probe infrared spectra of the hydrogen stretch in a moderately strong hydrogen-bonded complex dissolved in a polar solvent. Particular emphasis is put on incorporating nonadiabatic transitions and accounting for their unique spectral signature.