We propose a simple and accurate model for state-specific dissociation rate coefficients based on the widely used Treanor-Marrone model. It takes into account the dependence of its parameter on temperature and vibrational level and can be used with arbitrary vibrational ladder. The model is validated by comparisons with state-specific dissociation rate coefficients of O-2 and N-2 obtained using molecular dynamics, and its good accuracy is demonstrated. Non-equilibrium kinetics of O-2/O and N-2/N mixtures under heat bath conditions is studied; applying the optimized Treanor-Marrone model leads to more efficient dissociation and vibrational relaxation. (C) 2016 Elsevier B.V. All rights reserved.