Studies on Intermolecular Energy Transfer and Relaxation Processes in Solid Rare Earth Complexes by Photoacoustic Spectroscopy

The photoacoustic spectra of Eu ( benz)(3) (.) ( phen)(2) ( benz: benzoate, phen: phenanthroline) and Eu-0.(8)Ln(0.2)(benz)(3)(.)(phen)(2)(Ln(3+) : La3+ or Nd3+) were reported. The intermolecular energy transfer processes were studied from the point of the nonradiative transitions. Combined with the fluorescence spectroscopy, photoacoustic spectroscopy reflects the variation of the luminescence efficiencies of solid samples. The luminescence efficiency increases when La3+ is introduced, but it decreases greatly when Nd3+ is added, which is due to the difference of intermolecular energy transfer processes. The models of intramolecular and intermolecular energy transfer and relaxation processes were established.

Standard Enthalpies of Formation for Solid Complexes of Chromium Chloride with L-α-Amino Acids

The solid complexes of Cr(AA) 2Cl 3·nH 2O of CrCl 3 with L-α-amino acids (AA=Val, Leu, Thr, Met, Arg, Phe, Try and His) have been prepared in 95% EtOH medium, and characterized structurally by elemental analysis, chemical analysis, IR spectra and TG-DTG. The constant-volume combustion energies of the complexes have been determined by RBC-II type rotating-bomb calorimeter. The standard enthalpies of formation of the complexes have been calculated as well, which are ( -2543.16± 3.71) (Val), ( -2561.32± 4.06) (Leu), ( -2284.02± 2.95) (Thr), ( -1418.77± 4.60) (Met), ( -3218.91± 4.67) (Arg), ( -2643.90± 5.02) (Phe), ( -1707.18± 3.23) (Try) and ( -2838.05±3.45) (His) kJ/ mol, respectively.

Microstructural analyses of all-solid-state Li–S batteries using LiBH4-based solid electrolyte for prolonged cycle performance

Complex hydride materials have been widely investigated as potential solid electrolytes because they have good compatibility with the lithium metal anodes used in all-solid-state batteries. However, the development of all-solid-state batteries utilizing complex hydrides has been difficult as these cells tend to have short cycle lives. This study investigated the capacity fading mechanism of all-solid-state lithium–sulfur(Li–S) batteries using Li4(BH4)3I solid electrolytes by analyzing the cathode microstructure. Crosssectional scanning electron microscopy observations after 100 discharge–charge cycles revealed crack formation in the Li4(BH4)3I electrolyte and an increased cathode thickness. Raman spectroscopy indicated that decomposition of the Li4(BH4)3I solid electrolyte occurred at a constant rate during the cycling tests.To combat these effects, the cycle life of Li–S batteries was improved by increasing the amount of solid electrolyte in the cathode.

Synthesis of Solid Complex of Tl[(RO)_2PSO] and Its Property

The extraction behavior of thallium (Tl￣+ , Tl￣(3+) ) with D_2EHMTPA di-(2-ethythexyl) monothiophcos-phoric acid from sulfuric acid has been studied and compared with D_2EHPA. The solid complex of Tl[(RO)_2PSO] has been synthesised. Its composition was determined by scanning electron microscopy, energydispersion X-ray spectrometry and slope method. The IR and NMR spectra studies showed that thallium coordi-nates with P=S bond. The heating stability of the complex has been studied by TG-DTA analysis.

IONIC CONDUCTIVITIES OF SEGMENTED POLYETHER POLYURETHANEUREA COMPLEXES WITH LiClO_4

Ionic conductivity values for segmented polyether polyurethaneurea (PEUU) complexes with LiClO_4 were determined and values as high as～1.1×10^(-4) S·cm^(-1) at 353K and～1.0×10^(-5)S·cm^(-1) at 306K were achieved. The ionic conductivity data were analyzed using the VTF (Vogel-Tamman-Fulcher) equation and WLF (Williams-Landel-Ferry) type equation. Values have been estimated for the 'apparent' activation energies of ion transport from VTF equation and they lie in the range 2.70—5.53 kJ·mol^(-1).

STUDIES ON SOLID STATE REACTIONS OF COORDINATION COMPOUNDS(LXⅡ)Solid state synthesis and crystal structure of the complex ICu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)CIJ·0.5CS_2

[Cu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)Cl]·0.5CS_2=,Mr=895.79,monoclinic,space group P2_1/a,a=17.231(3),b=14.611(2),c=18.000(3) ,β=105.56(2)°,V=4365(1) ~3, Z=4,D_c=1.37g/cm^3.,λ(MoK_α)=0.71073 ,μ=12.15cm^(-1),F(000)=1855,R=0.052, R_W=0.045 for 3930 observed reflections with Ⅰ>1.5σ(Ⅰ).The central metal atom has a dis. torted tetrahedral geometry with bond lengths Cu-S=2.384(2) (Au-S=2.389(4)), Cu-Cl=2.481(3)(Au-Cl=2.474(1))and Cu-P=2.269(2)-2.289(2)(Au-P=2.270(4)-2.279(4)) .

Thermal Behavior of Zn(Thr)SO_4·H_2O

Solid complex Zn(Thr)SO 4·H 2O was prepared in a water acetone system. Under linearly increasing temperature, the non isothermal kinetics and the decomposition mechanism of Zn(Thr)SO 4·H 2O were studied by means of thermogravimetry and IR spectrometry. The thermal decomposition processes of the complex could be divided into three stages. The non isothermal decomposition mechanism and the kinetics parameters of the ligand lost process were obtained from an analysis to the TG DTG curves at various heating rates of 5 0, 10 0, 15 0 and 20 0 K/min by two integral and three differential methods. The results show that the random nucleation and the subsequent growth mechanism ( n =3/2) controlled the ligand lost process, the corresponding activation energy E and pre exponential constant A are 139 96 kJ/mol and 10 11 32 s -1 , respectively. The empirical kinetics model equation was constructed.

Catalytic Reduction of SO_2 on CeO_2-La_2O_3 Rare Earth Mixed Compounds

Adding rare earth oxide CeO_2 with variable valences to La_2O_3 formed a mixture of rare earth oxides. By means of dipping CeO_2, La_2O_3 and their mixture, whose carriers were all γ-Al_2O_3, were used as the catalyst for the reduction of SO_2 by CO. The activation process of this catalyst and the impact of temperature and reactant concentration on the activation process were investigated. Using X-ray diffraction, the structure characteristics of catalyst before and after reaction were analyzed to reveal the change of phase structure. The result shows that the rare earth oxide mixtures composing of CeO_2 and La_2O_3, as the catalyst for the reduction of SO_2 by CO, diminish activation temperature 50～100 ℃ less and have higher activity than a single oxide CeO_2 or La_2O_3. The reason possibl is that La_2O_3 goes into in the lattice of CeO_2 to form solid phase complex CeO_2-La_2O_3 and increases the capability of CeO_2-La_2O_3/γ-Al_2O_3 catalyst to store oxygen, which supplies the redox of CeO_2 reaction with a better condition. At the same time, elemental sulfur formed in the redox reaction impels La_2O_3 to be transformed to activation phase La_2O_2S in a lower temperature, which can be explained with the synergism between redox reaction and COS intermediate mechanism reaction.

COMPLEX REACTIONS OF ETHYL-GLUCOSIDES SYNTHESIS OVER ION EXCHANGE RESIN

The glycosidation reactions of D-glucose with ethanol have been carried out over a reusable and separable heterogeneous catalyst, namely, ion exchange resin. Detailed kinetic data for these reactions are reported. A complex reaction model has been developed for interpreting the data. The reactions were found to be global second-order reactions and first -order with respect to each component. Meanwhile, a new regression method is applied to determine the rate constant from time-dependent profiles.

Thermochromic and Magnetic Properties of a Copper(Ⅱ)Coordination Compound

Copper complexes that can experience reversible heat-induced dehydration and rehydration in the solid state were rarely reported although thermochromic copper complexes have been widely reported, and their heat-induced magnetic properties have not been studied. We firstly observed the reversible thermochromic phenomena of the known copper（II） complex [Cu（bpy）（OOCCH3）2]n·xn H2O（x = 2.5 or 3; bpy = 4,4＇-bipyridine） in the solid state, which is associated with the dehydration and rehydration processes, and found that heat-induced coloration clearly enhanced the magnetic susceptibility.

Complex effective depth approximation for soft solid bottom

In this paper, the approximate equation of Chapman's (real) effective depth for Pekeris guide is extended to the complex effective depth approximation whose real and imaginary parts explicate respectively the phase change and energy loss on reflection. It is shown that the homogeneous acoustic field, which comprises the complex effective depth approximation,closely reproduces the character of low modes at small grazing angles, and calculates effectively the acoustic field at longer ranges in shallow water. Application of the complex effective depth approximation can be extended to bottoms having two soft solid layers.

Crystalline inclusion complexes formed between the drug diflunisal and block copolymers

The solid form of drugs plays a central role in optimizing the physicochemical properties of drugs,and new solid forms will provide more options to achieve the desirable pharmaceutical profiles of drugs.Recently,certain drugs have been found to form crystalline inclusion complexes（ICs） with multiple types of linear polymers,representing a new subcategory of pharmaceutical solids.In this study,we used diflunisal（DIF） as the model drug host and extended the guest of drug/polymer ICs from homopolymers to block copolymers of poly（ethylene glycol）（PEG） and poly（s-caprolactone）（PCL）.The block length in the guest copolymers showed a significant influence on the formation,thermal stability and dissolution behavior of the DIF ICs.Though the PEG block could hardly be included alone,it could indeed be included in the DIF ICs when the PCL block was long enough.The increase of the PCL block length produced IC crystals with improved thermal stability.The dissolution profiles of DIF/block copolymer ICs exhibited gradually decreased aqueous solubility and dissolution rate with the increasing PCL block length.These results demonstrate the possibility of using drug/polymer ICs to modulate the desired pharmaceutical profiles of drugs in a predictable and controllable manner.

Drug-polymer inclusion complex as a new pharmaceutical solid form

The solid forms of drugs play a central role in controlling their physicochemical properties and consequently the bioavailability. Multiple types of drug solid forms have been developed to achieve the desirable pharmaceutical profiles, but new solid forms will provide more options for the solid-state property optimization and hence are highly desirable. This review focuses on a new pharmaceutical solid form, drug-polymer inclusion complexes （ICs）, and summarizes their structural features, structure- property relationships, as well as potential pharmaceutical applications

Determination of the Specific Heat Capacity of RE（Et2dtc）3（phen） by Microcalorimetry

A calculation formula for determining the specific heat capacity of solid compound with an improved RD496-Ⅲ microcalorimeter was derived. The calorimetric constant and precision determined by the Joule effect were （63.901±0.030）μV/mW and 0.3% at 298.15 K, respectively, and the total disequilibrium heat has been measured by the Peltier effect. The specific heat capacities of two standard substances （benchmark benzoic acid and α-Al2O3） were obtained with this microcalorimeter, and the differences between their calculated values and literature values were less than 0.4%. Similarly, the specific heat capacities of thirteen solid complexes, RE（Et2dtc）3（phen） （RE=La, Pr, Nd, Sm-Lu, Et2dtc： diethyldithiocarbamate ion, phen： 1,10-phenanthroline） were gained, and their total deviations were within 1.0%. These values were plotted against the atomic numbers of rare-earth, which presents tripartite effect, suggesting a certain amount of covalent character in the bond of RE^3＋and ligands, according to Nephelauxetic effect of 4f electrons of rare earth ions.