In a recent publication, Drebushchak [ 1 ] has made the startling claim that “Thermodynamics is not a rigorous mathematical science.” He also stated that for a specific thermodynamic expression, “two different
AlPO 4 · 2H 2 O [ 9 ] AlPO 4 · H 2 O-H1-4 [ 8 ] and AlPO 4 -21 [ 2 ] and Al 1− x Fe x PO 4 ( x = 0) [ 4 ] precursors. By reason, the mechanism, thermodynamics and kinetics of solid-state reactions are needed in order to take advantage of this
Authors:Xuehang Wu, Wenwei Wu, Shushu Li, Xuemin Cui, and Sen Liao
-state reaction at room temperature and to study the kinetics and thermodynamics of the decomposition of NH 4 NiPO 4 ·6H 2 O using TG-DTA technique. Non-isothermal kinetics of the decomposition process of NH 4 NiPO 4 ·6H 2 O was interpreted by Flynm
Authors:Bao-Di Xue, Qi Yang, San-Ping Chen, and Sheng-Li Gao
A new high-nitrogen complex [Cu(Hbta)2]·4H2O (H2bta = N,N-bis-(1(2)H-tetrazol-5-yl) amine) was synthesized and characterized by elemental analysis, single crystal X-ray diffraction
and thermogravimetric analyses. X-ray structural analyses revealed that the crystal was monoclinic, space group P2(1)/c with lattice parameters a = 14.695(3) Å, b = 6.975(2) Å, c = 18.807(3) Å, β = 126.603(1)°, Z = 4, Dc = 1.888 g cm−3, and F(000) = 892. The complex exhibits a 3D supermolecular structure which is built up from 1D zigzag chains. The enthalpy change
of the reaction of formation for the complex was determined by an RD496–III microcalorimeter at 25 °C with the value of −47.905 ± 0.021 kJ mol−1. In addition, the thermodynamics of the reaction of formation of the complex was investigated and the fundamental parameters
k, E, n,
were obtained. The effects of the complex on the thermal decomposition behaviors of the main component of solid propellant
(HMX and RDX) indicated that the complex possessed good performance for HMX and RDX.
Authors:Silvia Piero, Andrea Melchior, Davide Menotti, Marilena Tolazzi, and Anders Døssing
An investigation on the thermodynamics of complex formation between Ag(I) ion and two tripodal ligands tris[(2-pyridyl)methyl]amine
(TPA) and 6,6′-bis-[bis-(2-pyridylmethyl)aminomethyl]-2,2′-bipyridine (BTPA) has been carried out in the aprotic solvents
dimethylsulfoxide (DMSO) and dimethylformamide (DMF) by means of potentiometry and titration calorimetry. The results for
TPA are compared with those already obtained for other aliphatic tripodal polyamines. In general, the TPA ligand forms complexes
less stable than 2,2′,2″-triaminotriethylamine (TREN) and tris(2-(methylamino)ethyl)amine (Me3TREN) as a result of the combination of higher structural rigidity of TPA and lower σ-donor ability of pyridinic moieties
with respect to primary and secondary amines. The same trend is found if the stability of Ag(I) complex with TPA is compared
with that of tris(2-(dimethylamino)ethyl)amine (ME6TREN), despite the pyridinic nitrogen is formally a tertiary one. Theoretical calculations run to explain the reasons of this
weaker interaction indicate that this difference is due to solvation, rather than to steric or σ-donor effects. The ligand
BTPA is able to form bimetallic species whose relative stability is largely influenced by the different solvation of Ag(I)
ion in DMSO and DMF rather than by the difference in the dielectric constants of these two media.
Authors:Zhipeng Chen, Qian Chai, Sen Liao, Yu He, Wenwei Wu, and Bin Li
of the system research, the aim of this study was to prepare single phase α-LiZnPO 4 ·H 2 O via the above method with LiH 2 PO 4 ·H 2 O, ZnSO 4 ·7H 2 O, and Na 2 CO 3 and to study the kinetics and thermodynamics of the decomposition of α-LiZnPO 4 ·H
Authors:E. Matteoli, L. Lepori, T. Usacheva, and V. Sharnin
The influence of H2O–EtOH and H2O–Acetone mixed solvents at various compositions on the thermodynamics of complex formation reaction between crown ether 18-crown-6
(18C6) and glycine (Gly) was studied. The standard thermodynamic parameters of the complex [Gly18C6] (log K°, ΔrH°, ΔrS°) were calculated from thermochemical data at 298.15 K obtained by titration calorimetry. The complex stability and its formation
enthalpy increase with increasing the non aqueous component concentration in both mixed solvents. The thermodynamic data were
discussed on the basis of the solvation thermodynamic approach and the solvation contributions of the reagents and of the
complex to the complex stability were analyzed.
Authors:W. Zielenkiewicz, I. Terekhova, M. Wszelaka-Rylik, and R. Kumeev
Calorimetry, densimetry, 1H NMR and UV–vis spectroscopy were used to characterize inclusion complex formation of hydroxypropylated α- and β-cyclodextrins
with meta- and para-aminobenzoic acids in aqueous solutions at 298.15 K. Formation of more stable inclusion complexes between para-aminobenzoic acid and cyclodextrins was observed. The binding of aminobenzoic acids with hydroxypropyl-α-cyclodextrin was
found to be enthalpy-governed owing to the prevalence of van der Waals interactions and possible H-binding. Complex formation
of hydroxypropyl-β-cyclodextrin with both acids is mainly entropy driven. The increased entropy contribution observed in this
case is determined by dehydration of solutes occurring during the revealed deeper insertion of aminobenzoic acids into the
cavity of hydroxypropyl-β-cyclodextrin. By comparing complex formation of aminobenzoic acids with native and substituted cyclodextrins
it was found that the availability of hydroxypropyl groups slightly influenced the thermodynamic parameters and did not change
the binding mode or driving forces of interaction.
Authors:M. Pappalardo, M. Sciacca, D. Milardi, D. Grasso, and C. La Rosa
The role played by the metal ion in thermodynamics of azurin folding was addressed by studying the thermal denaturation of
the apo-form by differential scanning calorimetry (DSC), and by comparing the results with data concerning the holo protein.
The thermal unfolding experiments showed that at 25°C the presence of metal ion increases the thermodynamic stability of azurin
by 24 kJ mol−1. A comparison between the unfolding and the copper binding free energies allow us to assert that the unfolded polypeptide
chain binds copper and subsequently folds into native holo azurin, being this the thermodynamically most favourable process
in driving azurin folding.