ISSN:
1572-9001
Keywords:
Thermochemistry
;
2,2,6,6-tetramethyl-3,5-heptanedione
;
mean enthalpy
;
β-diketonates
;
lanthanide elements
;
lanthanide-oxygen bond
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The general thermochemical reaction LnCl3·6H2O(c)+3Hthd(1)+73.92H2O(1) = Ln(thd)3(c) +3HCl·26.64H2O(aq); ΔrHm (Ln = Pr, Ho and thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) was employed to determine through solution-reaction calorimetry at 298.15 K the standard molar enthalpies of formation of crystalline chelates, −2434.3±11.5 (Pr) and −2384.8±11.5 (Ho) kJ mol−1. These values and the corresponding molar enthalpies of sublimation enabled the determination of the standard molar enthalpies of chelates in the gaseous phase. From these values the mean enthalpies of the lanthanide-oxygen bond, 265±10 (Pr) and 253±10 (Ho) kJ mol−1 were calculated.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00681206
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