The rovibrational state distributions for the H-2 product of the H + n-C5H12/n-C6H14-->H-2 + C5H11/C6H13 reactions at 1.6 eV collision energy are reported. The results are compared to measurements made on the kinematically and energetically similar H + RH -->H-2 + R (RH = CH4, C2H6, and C3H8) reactions as well as the atom-diatom reactions H + HX -->H-2 + X(HX = HCl, HBr). For the title reactions, as for all the comparison reactions, the product appears in few of the energetically accessible states. This is interpreted as the result of a kinematic constraint on the product translational energy. Characteristic of the H + RH reactions we have previously studied, the title reactions show increasing rotational excitation of the H-2 product with increasing vibrational excitation of it, a correlation that gets stronger as the size of the alkane increases. Trends and variations in the product energy disposal are analyzed and explained by a localized reaction model. This model predicates a truncation of the opacity function due to competing reactive sites in the polyatomic alkane reactant, and a relaxation of the otherwise tight coupling of energy and angular momentum conservation, because the polyatomic alkyl radical product is a sink for angular momentum. (C) 2001 American Institute of Physics.