ABSTRACT

Low-temperature heat capacities of the solid coordination compound trans-Cu(Ala)2(s) have been measured by a precision automated adiabatic calorimeter over the temperature range from T = 78K to 390 K. The experimental values of the molar heat capacities in the temperature regionwere fitted to a polynomial equation of heat capacities (Cp,m) with the reduced temperatures (X), [X = f (T)], by a least square method. The smoothed molar heat capacities and thermodynamic functions of the complex trans-Cu(Ala)2(s) were calculated based on the fitted polynomial. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15K were tabulated with an interval of 5K. Enthalpies of dissolution of {Cu(Ac)2*H2O(s) + 2Ala (s)} and 2:1 HAc (aq) in 100ml of 2 moldm-3 HCl, respectively, and trans-Cu(Ala)2(s) in the solvent [2:1 HAc (aq) + 2 moldm-3 HCl] at T = 298.15K were determined to be SH.m[Cu(Ac)2 * H2O(s) + 2Ala(s)] = (6.75 +- 0.04) kJmol-1, SH.m[2 : 1HAc(aq)] = -(1.63 +- 0.01) kJmol-1, and SH.m [trans-Cu(Ala)2(s)] = -(10.24 +- 0.08) kJ mol-1 by means of an isoperibol solution-reaction calorimeter. The standard molar enthalpy of formation of the compound was determined as fH.m (trans-Cu(Ala)2(s), 298.15 K) = -(1038.6 +- 3.5) kJ mol-1 from the enthalpies of dissolution and other auxiliary thermodynamic data using a Hess thermochemical cycle.

Compounds

#	Formula	Name
1	C4H8CuO5	copper(II) acetate hydrate
2	C3H7NO2	(S)-2-aminopropanoic acid
3	C2H4O2	acetic acid
4	H2O	water
5	Cu	copper
6	H2	hydrogen
7	N2	nitrogen
8	C	graphite
9	O2	oxygen
10	C6H12CuN2O4	copper bis-L-alaninate

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	10	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	135
RXND	10 1 2 3 4	Molar enthalpy of reaction, kJ/mol				Solution calorimetry	1
RXND	10 5 6 7 8 9	Molar enthalpy of reaction, kJ/mol				Solution calorimetry	1

Thermodynamics Research Center / ThermoML | Thermochimica Acta

Low-temperature heat capacities and standard molar enthalpy of formation of the solid-state coordination compound trans-Cu(Ala)2(s) (Ala = l- -alanine)

Di, [You-Ying], Chen, J.-T.[Jing-Tao], Tan, Z.-C.[Zhi-Cheng]

ABSTRACT