Interaction energies obtained using CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ computations including both ZPE and BSSE corrections range from -2.9 to -14.2 kJ mol(-1). While formic acid forms the most stable complex with CO2, formaldehyde yields the least stable complex. Lewis acid-base interaction such as C-N center dot center dot center dot C(CO2), C = O center dot center dot center dot C(CO2), which overcomes C-H center dot center dot center dot O blue-shifting hydrogen bond, plays a significant role in stabilizing most complexes. However, the strength of (HCOOH, CO2) is mainly determined by O-H center dot center dot center dot O red-shifting hydrogen bond. The C-H center dot center dot center dot O blue-shifting hydrogen bond is revealed upon complexation of CH3OH, HCHO, HCOOH, CH3COCH3 and HCOOCH3 with CO2. Remarkably, existence of weak hydrogen bonded C-H center dot center dot center dot O interaction is not found in the (CH3OCH3, CO2) and (CH3NH2, CO2) pairs. (C) 2013 Elsevier B.V. All rights reserved.