Standard Molar Enthalpy of Formation of RE(C 5 H 8 NS 2 ) 3 ( o ‐phen)

Five solid ternary complexes of RE(C 5 H 8 NS 2 ) 3 ( o ‐phen) (RE=Ho, Er, Tm, Yb, Lu) have been synthesized in absolute ethanol by rare earth chloride low hydrate reacting with the mixed ligands of ammonium pyrrolidinedithiocarbamate (APDC) and 1,10‐phenanthroline·H 2 O ( o ‐phen·H 2 O) in the ordinary laboratory atmosphere without any cautions against moisture or air. IR spectra of the complexes showed that the RE 3+ coordinated with six sulfur atoms of three PDC ‐ and two nitrogen atoms of o ‐phen·H 2 O. It was assumed that the coordination number of RE 3+ was eight. The constant‐volume combustion energies of the complexes, Δ c U , were determined as (−16788.46±7.74), (−15434.53±8.28), (−15287.80±7.31), (−15200.50±7.22) and (−15254.34±6.61) kJ·mol ‐1 , respectively, by a precise rotating‐bomb calorimeter at 298.15 K. Its standard molar enthalpies of combustion, Δ c $ H^{\Theta}_{m} $ , and standard molar enthalpies of formation, Δ f $ H^{\Theta}_{m} $ , were calculated as (−16803.95±7.74), (−15450.02±8.28), (−15303.29±9.28), (−15215.99±7.22), (−15269.83±6.61) kJ·mol ‐1 and (−1115.42±8.94), (−2477.80±9.15), (−2619.95±10.44), (−2670.17±8.22), (−2650.06±8.49) kJ·mol ‐1 , respectively.