The coupling mechanism between an intense (10 13 Wc m -2 , 780 nm) near-infrared radiation field of duration 125 fs with molecules containing 12-28 atoms is considered in this article. The time-of-flight mass spectra are reported for the molecules benzene (C6H6), biphenyl (C12H10), diphenylmethane (C13H12), and diphenylethane (C14H14). The ionization of these molecules is compared with the predictions of a quasistatic tunneling model giving experimental/calculated yields for benzene, biphenyl, diphenylmethane, and diphenylethane of 1:1, 27:257, 59:113, and 134:467, respectively. The model correctly predicts the order of relative ion yields: benzene 10 13 Wc m -2 ), molecules can undergo bond softening 1 or laser-induced stabilization 4 due to the high electric fields, and this leads to dissociation. This photochemistry arises from the motion of the vibrational wave packet along dressed molecular potential surfaces in the intense laser field. Such effects must be considered because the photon densities can be very large, 6 10 8 photons per cubic wavelength at 10 13 Wc m -2 and 780 nm. These effects serve to complicate the application of atomic models of intense field ionization to molecules. Here, we demonstrate that such models do not even qualitatively reproduce the ionization trends for the polyatomic molecules. We show that the ionization trends are consistent with a structure-based model and suggest possible mechanisms for