Infrared Spectrum of Pyromellitic Diimide HN(CO)2C6H2(CO)2NH

The IR spectrum of pyromellitic diimide, HN(CO)₂C₆H₂(CO)₂NH, has been measured for polycrystalline sample. The observed bands have been assigned to the IR active fundamentals and combinations on the basis of a D_2h molecular symmetry by comparison with those of pyromellitic dianhydride. Band shifts from dianhydride to diimide were observed for the 0[dbnd]C-X-C[dbnd]O fundamentals and the N-H modes have been assigned by comparison with those reported for phthalimides.     

The Microwave Spectrum and Quadrupole Coupling Constants of cis-2-Chlorophenol

The rotational spectrum of cis-2-chlorophenol was observed from 5 to 12 GHz by molecular beam Fourier transform microwave spectrometer (MB-FTMW). The rotational and quadrupole coupling constants for the ³⁵Cl of the molecule were determined: A=2985.4479(22) MHz, B=1549.8591(3) MHz, C=1020.1915(1) MHz, χ_aa=−68.2429(83) MHz, χ₋=−0.922(20) MHz, χ_ab=−11.4(19) MHz. The quadrupole coupling constants of the chlorine nuclei of cis-2-chlorophenol were nearly equal to that of the chlorobenzenes. We concluded that the electric field gradient of the chlorine atom in cis-2-chlorophenol is similar to that of other chlorobenzenes, although the suggestion of intramolecular hydrogen bonding.     

Infrared and Raman spectra of aquamolybdenum (VI) oxide hydrate (MoO3·2H2O)

The infrared and Raman spectra of MoO₃·2H₂O are recorded and analysed on the basis of vibrations due to MoO₆ octahedra and H₂O molecules. Considerable changes in the frequencies of the octahedra have been observed due to strong distortion in the octahedral arrangement. The inactivev ₆ vibration of O _h symmetry became active in the Raman spectrum. Co-ordinated (aquated) and hydrated (interlayer) water molecules give rise to different frequencies.     

2-三氟甲基吡啶的转动光谱及分子结构研究

本文测定了2-三氟甲基吡啶在2∽20 GHz频率范围内的高分辨转动光谱. 测定了转动常数、¹⁴N核四极耦合常数及离心畸变常数等一系列光谱参数. 同时还在自然丰度下测定了5个¹³C和1个¹⁴N单取代同位素异数体的光谱数据. 实验结果结合从头算准确地推导出2-三氟甲基吡啶的骨架结构. 实验测得同位素异数体的平面转动惯量P_cc数值均为44.46 u?²,表明此分子具有C_s对称性. 此外,本文计算了吡啶、2-氟吡啶、2-甲基吡啶和2-三氟甲基吡啶的分子表面静电势,以此分析了三氟甲基的取代对电子分布的影响.     

基于叶绿素荧光光谱和反射光谱的甜瓜种子品种鉴别

甜瓜的品种多样,富含多种营养成分,甜瓜种子品种不纯将对甜瓜生产造成一定危害,研究采用种子的叶绿素荧光光谱结合反射光谱的分析方法鉴别甜瓜种子品种,以甜瓜品种“一特白”、“一特金”、“京蜜7号”、“京蜜11号”、“伊丽莎白”为研究对象。构建了甜瓜种子品种鉴别光谱系统,包括激发光源单元、光谱数据采集单元和数据处理单元,使用该系统获取不同品种甜瓜种子的光谱数据。对光谱数据分别进行一阶导数(first derivative, FD),Savitzky-Golay(SG) 平滑,FD结合SG平滑预处理。采用主成分分析(principal component analysis, PCA)方法降低光谱数据的维数,提取主成分。使用两种不同分组方法将样品按照3∶1的比例分为训练集和验证集,并分别采用Fisher判别和Bayes判别分析方法建立甜瓜种子品种的判别模型。本文比较了仅使用叶绿素荧光光谱与使用叶绿素荧光光谱结合反射光谱建立判别模型的判别结果,结果显示,使用叶绿素荧光光谱结合反射光谱建模的判别结果优于仅使用叶绿素荧光光谱建模的判别结果,Fisher判别分析和Bayes判别分析的验证集样品品种的判别正确率均达到98.0%。研究结果表明,采用叶绿素荧光光谱结合反射光谱鉴别甜瓜种子品种具有可行性。     

Spectroscopic and Structural Studies of Complex of [CU(DIEN)(CNGE)(ONO2)2] (Dien=Diethylenetriamine,CNGE=Cyanoguanid)

The electronic absorption spectrum (diffuse reflection spectrum) of the crystal of [Cu(dien)(cnge)(ONO₂)₂] has been measured. The experimental results are interpreted quantitatively with ligand field theory and the radial wave function of non-free copper (II), and our calculation values coincide well with the experimental results. As a result, the d-d absorption spectrum was explained satisfactorily. In particular, the structural characterizations whose degree of distortion of crystal structures of three Copper(II) complexes is different in this paper, are also discussed with their spectral behaviors. The experimental data provides significant correlation between the spectra and degree of distortion of coordination structures.     

Raman Spectrum of Chloromethyl Thiocyanate

Abstract

The liquid-state Raman spectrum was obtained for chloromethyl thiocyanate. The previously unobserved C-S-C bending band was observed at 188 cm^?1. The Raman spectrum supports the conclusion that only the C_S conformer is present.     

Raman spectroscopic study of the mineral guilleminite Ba(UO2)3(SeO3)2(OH)4·3H2O

The Raman spectrum of the mineral guilleminite Ba[(UO₂)₃O₂(SeO₃)₂](H₂O)₃ was studied and complemented by the infrared spectrum of this mineral. Both spectra were interpreted and compared with the spectra of marthozite, larisaite, haynesite and piretite, all of which should have the same phosphuranylite anion sheet topology. The presence of symmetrically distinct water molecules and hydrogen bonds was inferred from the spectra. This is in agreement with the crystal structural analysis of guilleminite. U O bond lengths in uranyl and O H···O hydrogen bond lengths were calculated from the Raman and/or infrared spectra of guilleminite. Copyright © 2008 John Wiley & Sons, Ltd.     

SPECTROSCOPIC PROPERTIES AND ELECTRONIC STRUCTURE OF [CuCl(L-PROLINATO)(H2O)]

ABSTRACT

[CuCl(L-Prolinato)(H₂O)] was prepared. Its electronic absorption spectrum and photoacoustic spectrum were recorded at the room temperature. A semi-empirical method of ligand-field-theory PLFT was utilized to calculate the d-d transition energy. According to the results, the spectrum was explained satisfactorily.     

Rotational Spectrum of the AsH(2) Radical in Its Ground State, Studied by Far-Infrared Laser Magnetic Resonance

The rotational spectrum of AsH₂ in its ground X̃²B₁ electronic state has been recorded using a far-infrared laser magnetic resonance spectrometer. The AsH₂ radical was produced inside the spectrometer cavity by the reaction of arsine (AsH₃) with fluorine atoms. Hyperfine splittings from both ⁷⁵As and ¹H nuclei were observed, and analysis of the spectra has yielded accurate values for rotational, hyperfine, and Zeeman parameters.     

The Raman Spectrum of Mercury (II) Iodide in High Temperature Solvents

Abstract

The Raman spectrum of mercury(II) iodide was observed in cesium nitrate at 430°C and in meta- and para-terphenyl at 235 and 240°C, respectively. A single strong polarized line was found at 148. 5 cm^?1, width at half height 15 cm^?1 in cesium nitrate, and a single line at 154. 0 cm^?1 width at half height 7 cm^?1 in the terphenyls. The observed spectra are not consistent with interactions of the solute and the solvents involving bonds of highly covalent character, but do not exclude other interactions.

In the course of an investigation on the nature of mercury (II) iodide species in solution in molten alkali metal nitrates, by its distribution between the salt melts and terphenyl melts^{1, 2}, it became of interest to study by means of Raman spectroscopy the mercury (II) iodide species formed. Several such studies at lower temperatures have already been made: in the gas phase³, in a krypton matrix⁴, in alcohols⁵, tributy phosphate⁶ and dioxame⁷, and in molten mercury(II) iodide⁸, chloride⁹, and bromide⁹. The reason for looking at the Raman spectrum in yetfurther media was the suggestion made on the basis of thermodynamic and kinetic data^2,10 that the mercury(II) iodide species in the alkali mitrate melts are solvated by nitrate anions, and that possiby the mixed anion terrahedral species HgI₂(NO₃)₂ is formed. Recent Ranan sepctrophotometric data on mixed halide anionic complexes of mercury₁₁ identified prominent lines of the spectrum of the species HgBr_nI^2– _4–n, including HGBr₂I₂ ^2–, so that a comparison could be made. The solubility of mercury (II) iodide in molten alkali metal nitrates is rather small, expect for cesium nitrate¹², Where the solubility should be sufficent for the Raman spectrum to be recorded. Also, it was comcluded from vapor pressure osmometric data in aromatic solvents that demiric species of mercury(II) halides (even a trimeric species of the iodide) are found, in which the mercury has a distorted octahedral coordination, with three halogen atoms bonded to a mercury atom in the dimer¹³. In terphenyl melts, the solubility     

Exchange interaction at the supramolecular level. EPR investigation of two copper (II) compounds: [Cu2(acac)2(phen)2(bpe)](CIO4)2·(bpe)·CH3CN·H2O and [Cu2(acac)2(phen)2(bpp)](CIO4)2·6H2O (bpe=trans-1,2-bis(4-pyridyl)ethylene, bpp=bis(4-pyridyl)propane)

Intra- and intermolecular exchange and dipole-dipole interactions in two supramolecular compounds [Cu₂(acac)₂(phen)₂(bpe)](CIO₄)₂·(bpe)·CH₃CN·H₂O (I) and [Cu₂(acac)₂(phen)₂(bpp)]× (CIO₄)₂·6H₂O (II), which are built up of binuclear fragments through π-π stacking interactions, are investigated. The electron paramagnetic resonance (EPR) spectra of the polycrystalline samples of I and II were measured in the X-band in the temperature range of 300–4.2 K, and in the Q-band atT=300 and 4.2 K. The EPR spectra were interpreted as being due to weakly interacting dimer fragments. Triplet and singlet states of dimer fragments arise from a larger interactionJS ₁ S ₂ between two nearest copper complexes of two neighboring binuclear fragments. The theoretical analysis of the EPR spectrum of the polycrystalline sample for weakly interacting triplet states is carried out. The influence of the weak interaction between triplet states with value ofJ′ is considered in the model of the frequency exchange. A special attention is focused on the presence of the additional signal due to the exchange merging in some orientations where theJ′ value exceeds the fine structure parameters of the spectrum. The analysis of the conditions for the detection of the additional signal and of the influence of this signal on the form of the EPR spectrum allows us to estimate the value of the exchange interactionJ′=o.025±0.005 cm^?1 for compounds I and II and anisotropic part of exchange interaction between two nearest copper complexes asJ _zz =?0.02 cm^?1,J _xx.yy =0.01 cm^?1 for compound I.     

Raman spectroscopic study of the uranyl selenite mineral demesmaekerite Pb2Cu5(UO2)2(SeO3)6(OH)6·2H2O

The Raman spectrum of the uranyl selenite mineral demesmaekerite was studied, complemented by the infrared spectrum and tentatively interpreted. The observed bands were attributed to the stretching and bending vibrations of (UO₂)²⁺, (SeO₃)²⁻ and OH groupings. U O bond lengths in uranyl and O H···O hydrogen bond lengths were calculated from Raman and/or infrared spectra and compared with published data. Copyright © 2008 John Wiley & Sons, Ltd.     

Vibrational analysis of NaM2OH(H2O)(MoO4)2/D2O [M=Ni,Zn]

The infrared and Raman spectra of NaNi₂OH(H₂O)(MoO₄)₂ and NaZn₂OH (H₂O)(MoO₄)₂ and their partially deuterated analogues are recorded and analysed on the basis of vibrations of MoO ₄ ²⁻ tetrahedra and H₂O molecules. The MoO ₄ ²⁻ groups are found to be more distorted in NaNi₂OH(H₂O)(MoO₄)₂ than in the other compound. Bands indicating the presence of H₃O⁺ ions are not observed in NaZn₂OH(H₂O)(MoO₄)₂ ruling out the possibility of the formulation of NaZn₂OHO(MoO₃OH)₂. Hydrogen bonds of medium strength are present in both the compounds.     

The Rotational Spectrum of Fluoroethyne (HCCF) Revisited

The pure rotational spectrum of fluoroethyne (fluoroacetylene, HCCF) has been reinvestigated. Rotational transitions have been measured in the frequency range from 230 up to 510 GHz and assigned to the excited vibrational states (υ₃υ₄υ₅)=(000), (001), (002), (003), (010), (011), (012), (020), and (100). The analysis of the spectrum extends the spectroscopic data for HCCF by correcting and refining the rotational and rovibrational constants determined in our previous investigation.     

The Rotational Spectrum of H2Te

In the present work, we study the spectrum of the H₂Te molecule in the submillimeter-wave and far infrared region. An important aim of this investigation is the further experimental characterization of the anomalous “four-fold cluster effect” exhibited by the rotational energy levels in the vibrational ground state of H₂Te. The spectrum in the region 90–472 GHz was measured with a source-modulated millimeter-wave spectrometer and that between 600 and 1600 GHz with a far-infrared sideband spectrometer. The far infrared spectrum from 30 to 360 cm⁻¹was measured with a Bruker IFS 120 HR interferometer attached to a 3 m long cell. We have assigned 224 submillimeter-wave lines and 1695 FIR lines. These observed data were supplemented by a large number of ground state combination differences derived from rotation–vibration bands of H₂Te, and the resulting large data set was analyzed by means of a modified Watson Hamiltonian. Accurate sets of rotational and centrifugal distortion constants for all eight tellurium isotopomers were obtained.     

Analysis of the ESR Spectrum of a Rhodium (II) Complex

Abstract

Rh(II) complexes are rather scarce¹ and often form dimeric structures, which are diamagnetic. The ESR spectra of definite Rh(II) species have so far been claimed for Rh in ZnWO₃ ², [Rh S₄C₄(CN)₄]^{2 ?}, ^3′4 [Rh(π-C₅H₅)₂]⁵, [(π-C₅H₅)Rh(π-C₂H₄)₂]⁺⁶, and an irradiation produced [RhCπ₂(CN)₄]^{2 ?} complex.⁷ A detailed analysis has been performed on the first², the second⁴ and the last⁷ complexes. The first system shows an almost axial symmetry and the unpaired electron has been assigned to the d_xy orbital² (the x,y,z axes are defined along the octahedral metal-ligand directions). The sulfur ligand complex and the dichlorotetracyano system have their unpaired electron in the d_Z ² orbital. ^4,7 In the course of studies ^8-10 on oxygenation of a Rh(I) complex, [RhCπ(C₈H₁₄)₂]₂, we observed ¹⁰ that a well defined ESR spectrum develops during the reaction in N,N′-dimethylacetamide (DMA) - lithium chloride media. For experimental detail, reference 10 should be consulted. The data summarized in the table refer to the spectrum B in that reference and are attributed to a Rh(II) species.     

EPR studies on aqueous sucrose solutions using (Cu(H2O)6)2+ spin probe

EPR investigations using Cu²⁺ ion as a probe have been performed on supersaturated sucrose solution with percent concentration c = 66 as a function of temperature T, and at room temperature as a function of c. The motionally averaged spectrum of [Cu(H₂O)₆]²⁺ was used to monitor the changes in intermolecular interactions that occur as a function of [c, T]. A drastic increase in the line width, symptomatic of increase in the rotational correlation time of [Cu(H₂O)₆]²⁺, is observed between 293 and 288 K. The motionally averaged spectrum disappears below 281 K. The motionally averaged spectrum is also absent in the room temperature spectra of the solution with c= 85. Even in the [c, T] range where [Cu(H₂O)₆]² is found to be nearly static, these molecules appear to have an orientational fluctuation manifesting in the m ₁ dependence of the line width of the parallel component.     

Simulation of the Electron Paramagnetic Resonance Spectrum of the Triplet Ground State Dimer Di-μ-(Pyridine N-Oxide)Bis[Bisnitrato(Pyridine N-Oxide)Copper(II)]

The EPR spectrum of the triplet ground state dimer di-μ-(pyridine N-oxide)bis[bisnitrato(pyridine N-oxide)copper(II)] has been reported recently¹. Of the very few triplet ground state copper(II) dimers with resolved metal hyperfine structure^2,3, the EPR spectrum of this complex is most complete. Previously, the analysis of the spectra of triplet ground state copper(II) complexes, in order to extract magnetic parameters, has been made using the equations reported by Wasserman et al.⁴ The best magnetic parameters should be obtained from a simulation of the experimental spectrum. We wish to report here the computer simulation of the EPR spectrum of a powdered sample of [Cu(II) (PYO)₂ (NO₃)₂]₂.     

Vibrational Spectra and Structure of Potassium Alum Kal(SO4)2·12[(H2O) x (D2O)1−x ]

The IR spectra and polarization Raman spectra of Kal(SO₄)₂·12(H₂O) and Kal(SO₄)₂·12[H₂O)_0.3(D₂O)_0.7] crystals at 93 K and room temperature have been obtained experimentally. The vibrational spectra of structural elements of potassium alum — the complexes [Al(H₂O)₆ ³⁺ and [Al(D₂O)₆]³⁺ — have been calculated. The vibrational spectra have been interpreted based on the calculation and factor-group analysis data. The spectral data obtained point to the fact that, in the crystals considered, the sulfate ions are partially disordered and there exist two crystallographically different types of water molecules.