A study of the rotational-torsional spectrum of hydrogen peroxide between 80 and 700 GHz

One hundred and thirty-three new rotational transitions that occur between pairs of torsional sublevels in the ground vibrational state of hydrogen peroxide have been measured in the 80 to 700 GHz region of the spectrum. These data, in combination with the 50 previously measured lines, have been theoretically analyzed to within the expected experimental uncertainty (?0.1 MHz). The rotational constants for the τ = 1, 2 state are (in MHz): A = 301 878.857 ± 0.015, B = 26 211.9019 ± 0.0059, C = 25 099.1400 ± 0.0059, and for the τ = 3, 4 state: A = 301 583.825 ± 0.075, B = 26 156.337 ± 0.13, C = 25 185.771 ± 0.13. The splitting between the torsional levels is 342 885.03 ± 0.05. These measurements and analysis accurately characterize the nine branches that make substantial contributions in the spectral region below 700 GHz.     

Calculation of intensities of torsional-rotational bands in the IR absorption spectrum of hydrogen peroxide

We present the calculated intensity distributions in torsional-rotational IR absorption bands of hydrogen peroxide. The torsional components of the band intensities have been calculated based on the appropriate matrix element computations. The contribution of the rotational components has been calculated using the 3j-symbols technique. The calculations have proved the reliability of available data on rotational constants, barrier heights of internal rotation, and locations of torsional-rotational levels of hydrogen peroxide. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 75, No. 2, pp. 153–158, March–April, 2008.     

光谱法对照研究肌红蛋白及其突变体Mb(D60K)与H_2O_2的相互作用

为了解肌红蛋白(Mb)表面60位天冬氨酸(Asp)突变为赖氨酸(Lys)后对蛋白结构稳定性的影响,本文通过紫外-可见吸收光谱、荧光光谱和停流荧光光谱对照研究了模拟生理条件下野生型肌红蛋白Mb(WT)及其突变体Mb(D60K)与过氧化氢(H2O2)的相互作用。结果表明:在Mb(D60K)与H2O2发生相互作用过程中,铁卟啉部位的紫外和荧光发射光谱数据与Mb(WT)相比,性质与功能均表现出显著差异。虽然只有一个氨基酸的改变,但其结构和性质发生明显变化,说明60位氨基酸在稳定蛋白结构中有重要的作用。同步荧光光谱和停流光谱的结果同样表明Mb(D60K)的结构与功能受H2O2的影响较小,Mb(WT)受H2O2影响明显。综合分析表明,Mb(D60K)在与H2O2相互作用过程中,蛋白结构稳定性提高。     

Detection of hydrogen peroxide with graphyne

The effect of hydrogen peroxide on the electronic properties of graphyne has been investigated to explore the possibility of using graphyne based biosensor. We have used density functional theory to study the electronic properties of γ-graphyne in the presence of different number of hydrogen peroxide. The optimal adsorption position, orientation, and distance of hydrogen peroxide adsorbed on the graphyne sheet have been determined by calculating adsorption energy. It is found that γ-graphyne which is an intrinsic semiconductor becomes an n-type semiconductor due to the presence of hydrogen peroxide. The energy band gap of γ-graphyne is decreased by increasing the number of hydrogen peroxide. The results demonstrate that γ-graphyne is a promising candidate for biosensor application because of its electrical sensitivity to hydrogen peroxide.     

Millimeter wave measurement and assignment of the rotational spectrum of aniline

Previous work involving the rotational spectrum of aniline was limited to the lower frequencies of 8-40 GHz with very few lines being assigned. This work extends the earlier studies. Here we present a much more extensive measurement and assignment of the rotational spectrum of aniline in the frequency range of 75-110 GHz. The observed frequencies have been assigned to the ground (0⁺), first (0⁻), and second excited (1⁺) states in the inversion vibration. With the newly assigned lines, significantly improved rotational constants and all five centrifugal distortion constants have been obtained.     

Photoinduced chirality of hydrogen peroxide molecules

The feasibility of using nonlinear optical techniques to control the chiral states of molecules is examined with the hydrogen peroxide molecule as an example. Raman excitation of optical activity owing to a transition among states with different chiral symmetries is proposed, along with an experimental scheme for detecting the corresponding photoinduced optical rotation in hydrogen peroxide vapor. Zh. éksp. Teor. Fiz. 116, 1250–1263 (October 1999)     

Non-commutativity of space-time and the hydrogen atom spectrum

There has been disagreement in the literature on whether the hydrogen atom spectrum receives any tree-level correction due to non-commutativity. Here we shall clarify this issue and show that indeed a general argument on the structure of the proton as a non-elementary particle leads to the appearance of such corrections. As a showcase, we evaluate the corrections in a simple non-relativistic quark model with a result in full agreement with the previous one we had obtained by considering the electron moving in the external electric field of proton. Thus the previously obtained bound on the non-commutativity parameter, , using the Lamb shift data, remains valid.Received: 10 October 2003, Revised: 12 November 2003, Published online: 2 July 2004     

Rotational statistics and thermodynamic functions of hydrogen peroxide

Partition functions for both the rotational modes (hindered internal rotation and overall rotation) of the hydrogen peroxide (H₂O₂) molecule in the ground electronic state are studied using quantum and classical Gibbsian statistical mechanics. The partition functions are used to calculate rotational thermodynamic functions (internal energy, enthalpy, Helmholtz free energy, Gibbs free energy and entropy) of a hydrogen peroxide gas of weakly interacting molecules at temperatures above 300 K.     

Millimeter and sub-millimeter wave detection of hydrogen peroxide

The measurement of small concentrations of hydrogen peroxide through the detection of rotational transitions in the millimeter and sub-millimeter wave regions is discussed. Calculated transition frequencies and absorption coefficients of H₂O₂ for frequencies up to 2000 GHz are presented. The reliability of the calculated values is illustrated by measurements of the linewidths and absorption coefficients of transitions in the 140 GHz range. Finally, methods for the detection of trace quantities of the peroxide molecule are briefly described.     

Observation of two-phonon difference bands in the FIR transmission spectrum of Si

The FIR transmission spectrum of Si has been measured between 100 and 400 cm⁻¹ by FTS at both 90 and 300 K. Weak absorption bands have been observed for the first time at 122 and 156 cm⁻¹ in addition to bands at 316 and 376 cm⁻¹ which have been reported before. The bands are assigned to two-phonon difference processes at the L, X and W points in the Brillouin zone.     

Measurement of the kaonic hydrogen x-ray spectrum

The DEAR (DAPhiNE exotic atom research) experiment measured the energy of x rays emitted in the transitions to the ground state of kaonic hydrogen. The measured values for the shift epsilon and the width Gamma of the 1s state due to the K(-)p strong interaction are epsilon(1s)=-193 +/- 37 (stat) +/- 6 (syst) eV and Gamma(1s)=249 +/- 111 (stat) +/- 30 (syst) eV, the most precise values yet obtained. The pattern of the kaonic hydrogen K-series lines, K(alpha), K(beta), and K(gamma), was disentangled for the first time.     

Ritz assignment and Watson fits of the high-resolution ring-puckering spectrum of oxetane

Oxetane is a four-membered ring molecule exhibiting a large-amplitude ring-puckering motion. In order to analyze this vibration we recorded a rotationally resolved far-infrared spectrum between 50 and 145 cm⁻¹. The analysis of the ring-puckering fundamental band with the assignment of 1108 lines, has been presented in a previous paper. In the present work we present a list of further 6531 assigned transitions between the five lowest excited ring-puckering states. The 4983 term values involved in the transitions assigned in this and in the preceding work have been evaluated by the “Ritz” program, and are now available. An A-reduced Watson Hamiltonian in any of the three representations I^r, II^r, and III^r was used to perform a fit of the assigned transitions. Precise rotational constants and quartic as well as a full set of sextic centrifugal distortion constants were obtained for the investigated ring-puckering states. For the first time, high-resolution values for the vibrational G_v parameters have been obtained, and we have added terms in x⁶ and x⁸ to the double minimum-potential well describing the ring-puckering motion, in order to reproduce their values within the experimental accuracy. The same potential still reproduces the lower resolution values of the Q-branch origins involving higher ring-puckering states up to v_rp=14 found in the previous literature.     

Millimeter wave measurement and assignment of the rotational spectrum of 2-aminopyridine

Previous work involving the rotational spectrum of 2-aminopyridine was limited to the lower frequencies of 4-40 GHz with very few lines being assigned. This work extends this earlier study. Here we present a much more extensive measurement and assignment of the rotational spectrum of 2-aminopyridine in the frequency range of 75-110 GHz. The observed frequencies have been assigned to the ground (0⁺ state) and the first excited state in the inversion vibration (0⁻ state). Measurements of these two states have been extended up to J=46. With the newly assigned lines, significantly improved rotational constants and all five centrifugal distortion constants have been obtained.     

Reaction of stannous fluoride in hydrogen peroxide

The reaction of SnF₂ stannous fluoride with aqueous solutions of H₂O₂ hydrogen peroxide was studied as a function of the molar ratio H₂O₂/SnF₂ in the range 0.02 to 5.00. The products were characterized by thermal analysis, X-ray diffraction and tin119 Mössbauer spectroscopy. The X-ray diffraction pattern of all samples shows only highly broadened lines, characteristic of microcrystalline SnO₂ (average particle diameter: 39 Å). Thermal analyses show that the material is hydrated. Mössbauer spectroscopy gives a broad single line at approximately 0 mm/s, characteristic of SnO₂ for all samples, and in some cases a tin(II) doublet with =3.1 mm/s and =1.9 mm/s.     

低压氢等离子体发光光谱

本实验使用2.45 GHz微波(100～200 W)激励产生低压(1～4 kPa)氢等离子体,通过光纤光谱仪探测氢等离子体的发射光谱,并分析了特征谱线分布及谱线强度随压强、功率的变化情况,计算了氢等离子体的电子激发温度.实验结果表明,压强由1 kPa增加至4 kPa,谱线强度减小;功率由100 W增大至200 W,谱线强度增大.随着压强的增大,电子激发温度减小或先减小后增大.     

SS433 and hydrogen spectrum beyond the Paschen-Back region

We examine the hydrogen spectrum in intense magnetic fields beyond the Paschen-Back region. Unlike in the Zeeman and Paschen-Back regions, the perturbations from the normal hydrogen spectrum increase as the magnetic fielddecreases!