Authors:S. Chen, X. Yang, Sh. Gao, R. Hu, and Q. Shi
The solid complexes of Cr(NO3)3 with L-α-amino acids (AA=Val, Leu, Thr, Arg, Phe and Try) have been prepared in 95% alcoholic, the compositions of which were identified as the general
formula Cr(AA)2(NO3)32H2O by elemental and chemical analyses. The bonding characteristics of the title complexes were characterized by IR, indicating
that nitrogen and oxygen atoms in the ligands coordinated to Cr3+ in a bidentate fashion. With the aid of TG-DTG and IR techniques, the complexes were subjected to thermal decomposition in
an atmosphere of oxygen, presuming that the decompositions of the complexes consist of two steps and the complexes were decomposed
into chromium hemitrioxide after undergoing dehydration and skeleton splitting of the complexes. The constant volume energies
of combustion of the complexes were determined by a RBC-P type rotating-bomb calorimeter. According to Hess's law, the standard
enthalpies of formation of the complexes were calculated as (-1831.404.40), (-2542.036.13), (-1723.813.99), (-2224.313.02),
(-2911.616.53) and (-659.327.42) kJ mol-1, respectively.
Authors:Y. Fan, Z. Gao, C. Bi, S. Xie, and X. Zhang
A new unsymmetrical solid Schiff base (LLi) was synthesized using L-lysine, o-vanillin and 2-hydroxy-l-naphthaldehyde. Solid lanthanum(III) complex of this ligand [LaL(NO3)]NO3·2H2O have been prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics
of the complex for the second stage was studied under non-isothermal condition by TG and DTG methods. The kinetic equation
may be expressed as: dα/dt=Ae−E/RT(1−α)2. The kinetic parameters (E, A), activation entropy ΔS# and activation free-energy ΔG# were also gained.
Authors:S. Chen, Sh Gao, X. Yang, R. Hu, and Q. Shi
Solid complexes of M(His)2Cl2nH2O (M=Mn, Co, Ni, Cu) of MnCl26H2O, CoCl26H2O, NiCl26H2O, CuCl22H2O and L-α-histidine (His) have been prepared in 95% ethanol solution and characterized by elemental analyses, chemical analyses,
IR and TG-DTG. The constant-volume combustion energies of the complexes have been determined by a rotating-bomb calorimeter.
And the standard enthalpies of formation of the complexes have been calculated as well.
The thermal decomposition behaviour of the complexes of rare earth metals with histidine: RE(His)(NO3)3
H2O (RE=La—Nd, Sm—Lu and Y; His=histidine) was investigated by means of TG-DTG techniques. The results indicated that the thermal decomposition processes of the complexes can be divided into three steps. The first step is the loss of crystal water molecules or part of the histidine molecules from the complexes. The second step is the formation of alkaline salts or mixtures of nitrates with alkaline salts after the histidine has been completely lost from the complexes. The third step is the formation of oxides or mixtures of oxides with alkaline salts. The results relating to the three steps indicate that the stabilities of the complexes increase from La to Lu.
Nano-ZnO flakes were synthesized by calcination of the precursor of Zn(OH)2 obtained via the reactive ion exchange method between an ion exchange resin and ZnSO4 solution at room temperature. Scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscope, UV-Vis
diffuse reflection spectrum and Na2EDTA titration were used to characterize the structure features and chemical compositions of the as-prepared ZnO. The results
show that the as-prepared ZnO flakes have uniform structure and high purity. Heat capacities in the temperature range of 83
to 396 K were measured. The measured heat capacities values were compared with those of coarse crystal powders and the difference
between this two heat capacity curves was analyzed.
Authors:Y. Zhang, X. An, X. Li, S. Chen, L. Gao, K. Wang, S. Wang, and Y. Yan
Two new y-type HMW-GSs in
with the mobility order of 1Dy12.2
>1Dy12, were identified by both SDS-PAGE and MALDI-TOF-MS. Molecular cloning and sequencing showed that the genes encoding subunits 1Dy12.1*
had identical nucleotide acid sequences with 1,947 bp encoding a mature protein of 627 residues. Their deduced molecular weights were 67,347.6 Da, satisfactorily corresponding to that of 1Dy12.2
subunit determined by MALDI-TOF-MS (67,015.7 Da), but was significantly smaller than that of the the 1Dy12.1*
subunit (68,577.1 Da). Both subunits showed high similarities to 1Dy10, suggesting that they could have a positive effect on bread-making quality. Interestingly, the expressed protein of the cloned ORF from accessions TD87 and TD130 in
co-migrated with subunit 1Dy12.2
, but moved slightly faster than 1Dy12.1*
on SDS-PAGE. The expressed protein in transgenic tobacco seeds, however, had the same mobility as the 1Dy12.1*
subunit, as confirmed by both SDS-PAGE and Western blotting. Although direct evidence of phosphoprotein could not be obtained by specific staining method, certain types of post-translational modifications (PTMs) of the 1Dy12.1*
subunit could not be excluded. We believe PTMs might be responsible for the molecular weight difference between the subunits 1Dy12.1*
Authors:S. Chen, X. Meng, Q. Shuai, B. Jiao, S. Gao, and Q. Shi
solid complex Eu(C5H8NS2)3(C12H8N2) has been obtained from reaction of
hydrous europium chloride with ammonium pyrrolidinedithiocarbamate (APDC)
and 1,10-phenanthroline (o-phen⋅H2O)
in absolute ethanol. IR spectrum of the complex indicated that Eu3+
in the complex coordinated with sulfur atoms from the APDC and nitrogen atoms
from the o-phen. TG-DTG investigation provided
the evidence that the title complex was decomposed into EuS.
enthalpy change of the reaction of formation of the complex in ethanol, ΔrHmθ(l), as –22.2140.081 kJ mol–1,
and the molar heat capacity of the complex, cm,
as 61.6760.651 J mol–1 K–1,
at 298.15 K were determined by an RD-496 III type microcalorimeter. The enthalpy
change of the reaction of formation of the complex in solid, ΔrHmθ(s), was calculated as 54.5270.314 kJ mol–1
through a thermochemistry cycle. Based on the thermodynamics and kinetics
on the reaction of formation of the complex in ethanol at different temperatures,
fundamental parameters, including the activation enthalpy (ΔH≠θ),
the activation entropy (ΔS≠θ),
the activation free energy (ΔG≠θ),
the apparent reaction rate constant (k),
the apparent activation energy (E), the
pre-exponential constant (A) and the reaction
order (n), were obtained. The constant-volume
combustion energy of the complex, ΔcU,
was determined as –16937.889.79 kJ mol–1
by an RBC-II type rotating-bomb calorimeter at 298.15 K. Its standard enthalpy
of combustion, ΔcHmθ,
and standard enthalpy of formation, ΔfHmθ,
were calculated to be –16953.379.79 and –1708.2310.69
kJ mol–1, respectively.
Authors:J. Liu, Y. Hou, S. Gao, M. Ji, R. Hu, and Q. Shi
The eight solid complexes of zinc with L--methionine or L--histidine were prepared. The thermal decomposition processes of these complexes were determined by means of TG-DTG. The results show that their decomposition processes can be divided into three steps except for the complex Zn(Met)2 the decomposition of which is completed in one step. All the final products are ZnO.
Authors:M. Ji, J. Liu, S. Gao, B. Kang, R. Hu, and Q. Shi
The enthalpies of solution in water of RE(His)(NO3)3
H2O (RE=La—Nd, Sm—Lu, Y) were measured calorimetrically at 298.15 K, and the standard enthalpies of formation of RE(His)aq3+ (RE=La—Nd, Sm—Lu, Y) were calculated. The plot of the enthalpies of solution vs. the atomic numbers of the elements in the lanthanide series exhibits the tetrad effect.