The thermal decomposition of [RuCl(η- p-cymene)] ( 1) and its biologically active N-alkylphenothiazine compounds of composition L[RuCl(η- p-cymene)] where L = CPH ( 2), TFH·HCl ( 3), and TRH ( 4) (chlorpromazine hydrochloride, CP·HCl; trifluoperazine dihydrochloride, TF·2HCl; and thioridazine hydrochloride, TR·HCl, respectively) has been studied. The crystal and molecular structure of compound 3 was determined earlier by single crystal X-ray diffraction analysis. The thermal data were collected by simultaneous TG/DSC measurements. For evolved gas detection, the qualitative reaction of chlorides with AgNO in an acidic solution was applied. The measurements were carried out in the temperature range to 700 °C in nitrogen atmosphere. Compounds of L[RuCl(η- p-cymene)] crystallize with water or water/2-propanole. On the basis of thermal data, the trend in the solvent bonding energies was assessed. [ABSTRACT FROM AUTHOR]