We report enthalpies of formation from the elements and oxides, DfH = (26195.31 +- 34.46) kJ mol 1 and Df;oxH = (1402.09 +- 33.36) kJ mol 1, for crystalline [Al13(l3-OH)6(l2-OH)18(H2O)24](NO3)15 11H2O(cr) (flat-Al13) measured using aqueous solution room temperature calorimetry. This material is a nitrate salt of a polynuclear aluminum hydroxide ion with thirteen aluminum metal centers, Al13 15+. Unlike the e-Al13 7+ Keggin ion, it contains solely octahedrally coordinated aluminum in a more flat topology. We also report heat capacities from temperatures of (2 to 300) K on this flat-Al13 nitrate using a Quantum Design Physical Property Measurement System (PPMS). These measurements were used to calculate the standard molar entropy and subsequently the free energy of formation for this material. We observed that during the heat capacity measurements, the flat-Al13 sample underwent a second order phase transition near T = 214 K.
Compounds
#
Formula
Name
1
NNaO3
sodium nitrate
2
ClH
hydrogen chloride
3
H2O
water
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.