We found that pseudopotentials, used with a recent novel hybrid meta-GGA density functional proposed by Zhao and Truhlar (M06) and density functionals applying long-range correction term (LC-BLYP, LC-BOP), exhibit very good accuracy in predicting thermochemical properties for a wide range of transition-metal complexes. The performance for thermochemistry of transition-metal complexes strongly depends on the valence-only chemical core potential basis sets used in the density functional theory (DFT) calculations. Recent chemical core potentials can be used for the theoretical thermochemistry of transition-metal complexes with an accuracy of about 20 kcal mol(-1). (C) 2011 Elsevier B.V. All rights reserved.