The intermediates formed from Mo(NO)2Cl2L2 and Mo(NO)Cl3L2 by splitting-off of weakly-coordinated ligandsL (alcohols, glycols, nitriles) decompose in exothermic reactions: the decomposition products are N2, MoOCl4 and MoO3. If the ligandL is strongly coordinated and is reducing (DMFA, DMSO, Pph3, Asph3), the NO groups oxidize the ligandL by formation of N2 in an exothermic intramolecular redox process under 300‡. The central atom is oxidized by NO, and N2O is formed above 300‡ in the case of non-reducing ligandsL (OPph3, OAsph3). An endothermic redox reaction with chlorine formation is observed during decomposition of the trichloro complex. The solid residue is metallic molybdenum.