The standard molar enthalpies of formation at T s 298.15 K of some crystalline bis 8-. hydroxy-2-methylquinolinate metal complexes were determined from solution-reaction calorimetric measurements. 8-Hydroxy-2-methylquinoline, or 2-methyloxine, is written as 0 . y1 Ä Ž . 4 Ž . Ž . Hmeox. The values of ⌬ H M meox , cr r kJ mol are: Mg meox , y609.0 " 4.5; f m 2 2 Ž . Ž . Ž . Ž . Ca meox , y707.8 " 4.5; Sr meox , y700.0 " 4.8; Cu meox , y176.6 " 4.4; Zn meox , 2 2 2 2 Ž . Ž . Ž . y 369.6 " 4.5; Cd meox , y298.0 " 4.5; Pb meox , y239.9 " 4.6; Mn meox , y418.1 " 4.3; 2 2 2 Ž . Ž . Co meox , y257.8 " 4.7; Ni meox , y243.0 " 6.6. Where feasible, the standard molar 2 2 enthalpies of sublimation at T s 298.15 K were determined by an effusion method. The g 0 . y 1 Ä Ž . 4 Ž . Ž . Ž . ⌬ H M meox r kJ mol values are: Mg meox , 224.3 " 6.5; Cu meox , 172.1 " cr m 2 2 2 Ž . Ž . Ž . Ž . 3.4; Zn meox , 179.4 " 5.0; Cd meox , 203.3 " 7.3; Pb meox , 188.6 " 5.9; Mn meox , 2 2 2 2 Ž . Ž . 211.2 " 7.2; Co meox , 204.4 " 5.9; Ni meox , 180.9 " 3.7. From the standard molar 2 2
enthalpies of formation in the gaseous state, the mean metal᎐ligand dissociation enthalpies were derived and compared with values for other complexes of these metals.