1) N-heterocyclic carbenes (NHCs) are stable two-coordinate carbon compounds that were first synthesized in 1991. Their stability is due to mesomeric and inductive effects from the nitrogen atoms that make the carbenes strong π-donors and weak σ-acceptors. 2) The thermodynamics of dissociation were studied for a bis(benzimidazol-2-ylidene), finding an enthalpy of 13.7 kcal/mol and entropy of 30.4 cal/mol*K. NHCs were also ranked based on their acidity. 3) NHCs form stable complexes with transition metals and have applications in organomet