钨酸钕单晶光谱及其上转移发光

采用提拉法生长出钨酸钕Nd2(WO4)3单晶,通过光谱测试研究了Nd^3 的能级结构,采用波长为808nm激光二极管作为激发光源,室温下观测到457和657nm两个波段的上转换荧光,分别相应于^2D5/2→^4I11/2和 ^2G7/2→^4I9/2跃迁,457和657nm处的上转移荧光强度与激发光功率分别成线性关系和平方关系。     

ChemInform Abstract: Prediction of the Fundamental Vibrational Frequencies for C60 by Local Density Functional Theory

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

Study on Infrared Spectra and Chemical Bonding of the Cluster Anion ［Cl_2FeS_2MoS_2Cu（PPh_3）_2］~－

ＳｔｕｄｙｏｎＩｎｆｒａｒｅｄＳｐｅｃｔｒａａｎｄＣｈｅｍｉｃａｌＢｏｎｄｉｎｇｏｆｔｈｅＣｌｕｓｔｅｒＡｎｉｏｎ［Ｃｌ_２ＦｅＳ_２ＭｏＳ_２Ｃｕ（ＰＰｈ_３）_２］~－ＫｏｎｇＸｉａｎ－Ｌｉｎｇ；ＣｈｅｎＺｈｉ－Ｄａ；ＳｈｅｎｇＴｉａｎ－Ｌｕ；ＷｕＸｉ...     

ChemInform Abstract: Matrix IR Investigations of Molecular SPBr.

SPBr, generated according to the scheme, is cocondensated with excess argon at 15 K. In the matrix IR spectrum the two stretching vibrations and the overtone of the bending mode are observed.     

ChemInform Abstract: Infrared Spectrum of a Symmetrical Phosphine-Ozone Complex in Solid Argon.

Cocondensation of Ar/PH₃ and Ar/O₃ samples at 12-18 K produces sharp satellite absorption bands.     

Comparative IR spectroscopic study of phosphorus-containing dendrimers built of thiophosphoryl, cyclophosphazene and phthalocyanine cores

The FTIR spectra of four generations of phosphorus-containing dendrimers built of thiophosphoryl, cyclophosphazene and phthalocyanine cores with terminal benzaldehyde and P–Cl groups have been recorded and analyzed. FT-Raman spectra of four generations of phosphorus dendrimers built of cyclotriphosphazene core with terminal benzaldehyde groups have been detected. Their spectral pattern is determined by the ratio T_n/R_n (T_n—number of terminal groups, R_n—number of repeating units). This ratio trends to r − 1 (r—branching functionality of repeating unit), and becomes constant, when the generation number is higher than 3. Experimental IR spectra of dendrimers built of thiophosphoryl, cyclophosphazene and phthalocyanine cores are very closely similar. The dependence of band full width at half height in IR spectra on the number of dendrons is established. The possibility appears to separate the bands assigned to the core, repeating units and terminal groups of dendrimers by difference spectroscopy method.     

ChemInform Abstract: FTIR Spectra of Hydroxylamine-Hydrogen Fluoride Complexes in Solid Argon.

Codeposition of HF and NH₂OH in excess argon at 12 K produces new IR absorption bands corresponding to perturbed acid and base submolecule vibrations for a 1:1 complex.     

ChemInform Abstract: IR Stark Spectroscopy of the Hydrogen-HF Binary Complex

clearly shows the HF subunit to undergo wide amplitude bending motion even in the zero-point vibrational state.     

结晶碳酸钕的水热合成、外观形貌及其组成

Crystalline neodymium carbonates were prepared by treating the amorphous precipitate formed from the reaction between neodymium chloride and ammonium bicarbonate under hydrothermal condition. Their composition, morphology and crystal phase were identified by means of elemental analysis, SEM and XRD. It was found that Nd₂(CO₃)₃·2.5H₂O with tengerite-type structure and sheet morphology was obtained when the feed molar ratio(FMR=n_(NH4)2CO2/n_NdCl3)was 2 or 1.8 and hydrothermally treated at 150 ℃ for 12h. However, orthogonal NdOHCO₃ particles agglomerated with long rod crystals were formed when lowering FMR to 1.5 under the same hydrothermal condition. Phase transformation from tengerite-type Nd₂(CO₃)₃·2.5H₂O to orthogonal NdOHCO₃ was occurred when increasing hydrothermal temperature or prolonging hydrothermal time, which is beneficial to the preparation of neodymium hydroxyl-carbonate with neodymium oxide content higher than 70%.     

ChemInform Abstract: High-Pressure Studies of Transition-Metal Complexes. Part 1. Induced Torsional Deformation in Re2Cl2- 8.

The pressure dependence of the electronic absorption and Raman spectra of a solution of (Bu₄N)₂Re₂Cl₈ in CH₂Cl₂ has been investigated.     

ChemInform Abstract: Trends in the Frequencies of ν(AsOxHx‐1) [x = 2—4] in Selected As(V)‐Containing Compounds Investigated Using Quantum Chemical Calculations.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

链状三核异金属簇阴离子［Cl_2FeS_2M＇（PPh_3）_2］~－（M＝Mo

在５５０～９０ｃｍ~（－１）波数范围内，测量簇阴离子［Ｃｌ_２ＦｅＳ_２ＭＳ_２Ｍ′（ＰＰｈ_３）_２］~－（Ｍ＝Ｍｏ，Ｍ′＝Ａｇ；Ｍ＝Ｗ，Ｍ′＝Ｃｕ，Ａｇ）的付里叶变换红外光谱，并对标题簇阴离子［Ｃｌ_２ＦｅＳ_２ＷＳ_２Ｃｕ（ＰＰｈ_３）_２］~－，［Ｃｌ_２ＦｅＳ_２ＭｏＳ_２Ａｇ（ＰＰｈ_３）_２］~－和［Ｃｌ_２ＦｅＳ_２ＷＳ_２Ａｇ（ＰＰｈ_３）_２］~－骨架的振动光谱给予经验指认。同时采用＂诱导自洽方法计算振动力常数＂程序，对簇骨架［Ｃｌ_２ＦｅＳ_２ＭＳ_２Ｍ~′Ｐ_２］进行简正坐标分析。振动频率的计算值与观测值符合良好，两者平均偏差小于１．０％，计算结果支持了振动谱带的归属并表明计算力常数的合理性。文中还讨论了主要价键振动频率的变化规律。     

Preparation and examination of properties of lanthanide chloride salts with hexamethylenetetramine

Summary New complex salts of lanthanide chlorides with hexamethylenetramine of the general formulaLnCl₃·2HMTA·nH₂O [Ln=La, Pr, Nd, Sm, Dy, Er;HMTA-hexamethylenetetramine N₄(CH₂)₆;n=8, 10, 12] have been obtained. On the basis of IR IR spectra (4000-200cm^–1) and Raman spectra (3000-300 cm^–1), changes in the coordination sphere structure of the salts occurring in the course of thermal dehydration have been determined.

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Darstellung und Untersuchung der Eigenschaften von Komplexsalzen der Lanthanidchloride mit Hexamethylentetramin

Zusammenfassung Neue Komplexsalze der Lanthanidchloride mit Hexamethylentetramin mit der allgemeinen FormelLnCl₃·2HMTA·nH₂O [Ln=La, Pr, Nd, Sm, Dy, Er;HMTA — Hexamethylentetramin N₄(CH₂)₆;n=8, 10, 12] wurden dargestellt. Die Änderungen in der Struktur der Koordinationssphäre während der thermischen Dehydration der Salze wurden mittels Infrarot-(4 000–200 cm^–1) und Ramanspektroskopie (3 000–300 cm^–) bestimmt.

     

Neodymium and europium complexes with amides and cyclic aminoxides

Complexes of neodymium and europium with amides and aminoxides were synthesized and characterized by complexometric analyses with EDTA, CHN microanalytical procedures, IR absorption spectra, absorption spectra of neodymium complexes, emission spectrum of europium compounds at 77 K, thermogravimetric analyses in N2 and differential scanning calorimetry (DSC) in N2. Infrared spectroscopy results revealed that the nitrate molecules are bound to the central ions as bidentate. Thermogravimetric plots indicated that the decomposition of the complexes occurs in the range 363-1163 K and resulted in the formation of Ln₂O₃ residues. This revised version was published online in August 2006 with corrections to the Cover Date.     

The effects of conformation and intermolecular hydrogen bonding on the structural and vibrational spectral data of naproxen molecule

The structural and vibrational properties of naproxen, an inhibitor of cyclooxygenase (COX) enzyme, were investigated by molecular modeling and experimental IR and Raman spectroscopic techniques. Possible conformers of the molecule were searched via a molecular dynamics simulation carried out with MM2 force field. The total energies, equilibrium geometries, force fields, IR and Raman spectral data of the found stable conformers were determined by means of geometry optimization and harmonic frequency calculations carried out using the B3LYP method and Pople-style basis sets of different size. The stability order obtained for the lowest-energy conformers was confirmed by high-accuracy thermochemistry calculations performed with G3MP2B3 composite method. Some electronic structure parameters of naproxen and the anharmonicity characters of its vibrational modes were determined by means of natural population analysis (NPA) and anharmonic frequency calculations at B3LYP/6-31++G(d,p) and B3LYP/6-311++G(d,p) levels of theory. A part of these calculations carried out for free naproxen molecule were repeated also for its energetically most favored dimer forms. Two different scaling procedures ((1) “SQM-FF methodology” and (2) “Dual scale factors”) were independently applied to the obtained harmonic vibrational spectral data to fit them to the corresponding experimental data. In the light of the obtained calculation results, which confirm the remarkable effects of conformation and intermolecular hydrogen bonding on the structural and vibrational spectral data, in particular, on those associated with the functional groups in the propanoic acid chain, a reliable assignment of the fundamental bands observed in the experimental IR and Raman spectra of the molecule was achieved.     

ChemInform Abstract: IR Spectra of Molecular B(OH)3 and HOBO in Solid Argon.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

ChemInform Abstract: Near-IR Absorption Spectra of C60 Radical Cations and Anions Prepared Simultaneously in Solid Argon.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.