气相CCl2自由基的发射光谱

在CCl₄蒸汽的直流放电中,观测了从520到630nm波长范围的荧光发射并确认为CCl₂自由基A→X跃迁。近400条谱带归属为³⁵Cl-C-³⁵Cl和³⁵Cl-C-³⁷Cl的(v₁′,v₂′,0)→(v₁″,v₂″,0)一系列前进带组,并排列成Deslandres表。光谱分析给出CCl₂在激发态和基态的v₁和v₂振动频率及同位素位移,其中气相CCl₂在基态的数据尚未见文献报道。 关键词：     

草酰氯的激光诱导荧光激发谱

本文报道草酰氯C₂O₂Cl₂在358—372.5nm范围的激光诱导荧光(LIF)激发谱。对60多条振动谱带进行了归属,其中24条是吸收光谱中没有的。由振动结构得到C₂O₂Cl₂分子在X基态和?激发态的部分振动频率,其中v＂₇=84cm^-1和v＇₇=164cm^-1是新的数据。对4₀¹振动带的转动结构的分析给出转动常数A=0.190cm^-1,B=0.114cm^-1,C=0.048cm^-1。 关键词：     

二正丁基锡(IV)基羧酸酯的谱学表征

合成了10个二正丁基锡(IV)基羧酸酯化合物{[ⁿBu₂Sn (O₂CR)]₂O}₂(A1~A5)和ⁿBu₂Sn (O₂CR)₂(B1~B5)(R=1:CCl₃;2:CHCl₂;3:CH₂Cl;4:PhCH=CH;5:2,2,3,3-四甲基环丙基),其中A4、A5和B5为新化合物,对它们进行了元素分析和IR及、¹H、¹³C、¹¹⁹Sn NMR谱表征,重点讨论了¹³C和¹¹⁹Sn NMR谱的谱学特征及化学位移值与母体酸的PKa值大小的关系,并在此基础上推测了它们分子结构。     

超声冷却SO2( 1A2— 1A1)激光诱导荧光激发谱的转动分析

通过改变SO₂/Ar配比，研究了超声膨胀冷却SO₂( ¹A₂— ¹A₁)系统315—330nm波段振动分辨的激光诱导荧光(LIF)激发谱.获得了属于两个完整带系(1,m,1),(0,n,1)—(0,0,0)的高分辨转动结构谱.其中(ν′₁,ν′₂,ν′₃)=(0,9,1),(0,10,1),(1,7,1),(1 关键词：     

激光诱导NO2分子500—532nm区荧光激发谱的实验研究

用准分子激光抽运可调谐染料窄带激光测定了室温下NO₂分子500—532nm区高分辨荧光激发谱,在两个较强吸收区505—510nm和513—520nm范围内标识了25个振动带,并作了转动分析,得到了相应的带头位置、转动常数和旋-转偶合常数等分子光谱常数,在25个振动带中有5个谱带是新发现的,所有得到转动分析的谱线均属于平行跃迁X～ ² A₁—A～²Ｂ₂,对实验结果的分析表明电子激发态A～ 关键词： 激光诱导荧光激发谱 振动带 转动分析     

332—362nm范围内CF2Cl自由基的共振增强多光子电离研究

用CF₂Cl₂分子直流脉冲放电的方法产生CF₂Cl自由基，结合共振增强多光子电离(REMPI)技术，测量了332—362nm波长范围内CF₂Cl自由基的(2+1)REMPI光谱，分析并标识了4s Rydberg态带源位于(ν_0—0=55371cm^-1)，两个被激活振动模ω′₃(CF₂剪式振动模)和ω₄′(OPL 关键词：     

Raman紫外双共振研究C2H2分子的碰撞转动弛豫

本文利用受激Raman抽运,选择性地制备了C₂H₂分子电子基态的红外非激活振动能级的单一转动态(X¹∑_g⁺,v″₂=1,J″=9,11,13),并从紫外激光诱导的A¹Au(v′₃=1)←X¹∑_g⁺(v″₂=1)荧光谱,直接测定上述三个转动态的C< 关键词：     

钠米Al2O3块体材料在可见光范围的荧光现象

对不同温度退火未掺Ｃｒ的纳米结构Ａｌ₂Ｏ₃块体的荧光谱进行了系统的研究。结果表明，在纳米级勃母石，η－Ａｌ₂Ｏ₃和γ－Ａｌ₂Ｏ₃试样中均观察到两个宽的荧光带（ｐ₁和ｐ₂带），它们的波数范围分别为２００００—１４５００和１４５００—１１５００ｃｍ^－１。ｐ₁带可归结为纳米Ａｌ_{2关键词：}     

BH分子8个Λ-S态和23个Ω态光谱性质的理论研究

本文利用内收缩多参考组态相互作用方法计算了BH分子8个低电子态(X~1∑~+、a~3∏,A~1∏,b~3∑~-,2~3∏,1~3∑~+,1~5∏~-和1~5∏)和在自旋-轨道耦合效应下所产生的23个Ω态的势能曲线、以及X~1∑_0~+~+,a~3∏_0~+,a~3∏₁,a~3∏₂和A~1∏₁态之间6对跃迁的跃迁偶极矩.为了获得精确的势能曲线,计算中修正了单双电子激发、核价相关效应、相对论效应和基组截断带来的误差.获得的BH分子的光谱和跃迁数据与现有的理论值和实验值符合得很好.计算结果表明:BH分子的A~1∏₁(v’=0-2,J’=1,+)→X~1∑_0~+~+(v"=0-2,J"=1,-)跃迁具有较大的爱因斯坦A系数和加权的吸收振子强度、高度对角化分布的振动分支比,A~1∏₁态具有较短的辐射寿命.另外,a~3∏_0~+和a~3∏₁态对A~1∏₁(v’=0)...     

氨分子在000和201带的选择光离解

本文利用脉冲紫外激光(UV)选择激发氨分子到?¹A″₂电子激发态的两个最低振动能级ν′₂=0和ν′₂=1(ν₂振动),然后检测新生态H原子的飞行谱(TOF),研究了氨分子的光碎片动力学。光谱证实了最近所测的离解能D₀⁰(H-NH₂)=4.645eV;绝大多数生成的NH₂(X²B₁)基处于非振动激发,但是具有围绕a惯性轴的高度转动激发。通过NH₃(?)的ν′₂=1光离解产生的NH₂(X)基具有较高的内部激发,并且显示了在N=K_a转动能级上的反转布居。 关键词：     

Higher ro-vibrational levels of H2O deduced from high resolution oxygen-hydrogen flame spectra between 6200 and 9100 cm-1

The spectra of hydrogen-oxygen and acetylene-oxygen flames have been recorded on a Fourier transform spectrometer in the region 6200–9100 cm^-1 with a resolution of 0·015 cm^-1. In this region, we have performed a detailed analysis of the 2v ₂ + v ₃, v ₁ + v ₃, v ₁ + v ₂ + v ₃ - v ₂ and v ₁ + v ₂ + v ₃ bands. A primary motive for this study was to obtain higher rotational energy levels for the (021), (101) and (111) vibrational states. Moreover an extensive set of rotational levels of the (010) vibrational state has been deduced from the combined study of hot bands involving the (011), (021) and (111) vibrational states. A room-temperature absorption spectrum of water recorded on a Fourier transform spectrometer in the region 1750–2300 cm^-1 (resolution 0·005 cm^-1) has also been used to confirm the analysis.     

Vibration-rotation analysis of the jet-cooled v12, v7 + v8 and v6 + v10 absorption bands of 12C2H4

A Fourier transform interferometer was used to record the slit-jet cooled absorption spectrum of ¹²C₂H₄ between 700 and 2400 cm^?1I, at a spectral resolution of 0.005 cm^?1. Three bands, v₁₂ at 1442.442 70(1)cm^?1, v₇ + v₈ at 1888.978 23(3)cm^?1 and v₆ + v₁₀ at 2047.775832(2)cm^?1, were rotationally analysed. In the case of 7¹8¹, a known Coriolis perturbation mechanism involving the nearby 4¹8¹ (1958.264cm^?1) and 8¹10¹ (1766.391 cm^?1) states was accounted for in the analysis. The latter fitting procedure included 12 levels from the 4¹8¹ state which are observed because lines from v₄ + v₈ borrow intensity from v₇ + v₈. Compared to the literature, significantly improved vibration-rotation constants were obtained for all upper states reported in the present study.     

Photoelectron spectra of halides

High resolution photoelectron spectra, obtained with He I (584 Å) resonance radiation, are reported for ClF, ClF₃, BrF₃ and BrF (partial spectrum). In some cases Ne I (736–744 Å) radiation has also been used. Spinorbit and vibrational fine structure is resolved for the ground ²II states of ClF⁺ and BrF⁺; values obtained for ClF⁺ and ζ = 630 cm^-1, v′ = 870 cm^-1, and for BrF⁺ ζ = 2600 cm^-1, v′ = 750 cm^-1. From the vibrational envelope of the X ²∏ states, a bond length change of δr _e (-)0·10 Å for ClF⁺ and BrF⁺ is estimated. Ab initio SCF-MO calculations for ClF and ClF₃ are used to aid in the interpretation of the spectra via Koopmans' theorem. A considerable amount of charge delocalization in the trifluorides is inferred from the photoelectron spectra, and this is borne out by the calculations.     

Rovibronic Levels for the (1-3)Πg Manifold of B2: Exterior Complex Scaling Finite Element Calculations Based on an Adiabatic and a Strictly Diabatic Basis

A one-dimensional complex scaled finite element method was applied on an adiabatic basis of B₂ in order to find rovibronic term energy values for the (1)³Π_g; (v, N)=(0-8, 0-25) and (2)³Π_g; (v, N)=(0-10, 0-25) levels. The method was also applied to the (1)³Π_g; (v, N)=(0-8, 0-25) and (2)³Π_g; (v, N)=(0-1, 0-25) levels in a strictly diabatic framework. Adiabatic single-channel and diabatic coupled-channel total wavefunctions were obtained and used in order to identify the vibrational levels. Comparing levels for the interacting two-state (1-2)³Π_g and three-state (1-3)³Π_g system, a constant energy shift of about 1.7 cm⁻¹ is found. Comparisons between the adiabatic Born-Oppenheimer (BO) and the diabatic (1)³Π_g; (v, N)=(0-8, 0-25) levels show differences between −20 and 7 cm⁻¹, while the corresponding shifts for the (2)³Π_g; (v, N)=(0, 0-25) and (1, 0-25) levels are about 50 and 60 cm⁻¹, respectively. A comparison between our three-state approximation and experimental observations of the (2)³Π_g-A³Π_u electronic transition shows a difference in the line positions of about 665 cm⁻¹. The calculated widths for all but the (1)³Π_g; (v, N)=(7-8, 0-25), as well as the (2)³Π_g; (v, N)=(0, 0-25) BO and diabatic rovibronic levels, have small but with N increasing predissociation rates. The (1)³Π_g; (v>8, N=0-25) BO and the (2)³Π_g; (v, N)=(1, 0-25) diabatic levels are strongly predissociated with widths ≥16 cm⁻¹.     

The integrated number of vibrational states in acetylene (12C2H2, 13C2H2, 12C2D2)

A calculated exhaustive set of vibrational state energies in ¹²C₂H₂, ¹³C₂H₂ and ¹²C₂D₂ has been used to analyse the evolution of the integrated number of states with increasing vibrational energy N(E) up to 15000 cm^?1, 12000cm^?1 and 10000 cm^?1 in each isotopomer, respectively. The regular contribution to N(E) was modelled analytically and numerical parameters were fitted. The other expected contribution to N(E), which is of oscillatory nature, was quantified and is discussed using energyand time-dependent theories. Related periods of oscillation and temporal recurrences are interpreted consistently in terms of the constant of the motion N_r = 5v₂ + 3v₂ + 5v₃ + v₄ + v₅ and of an average vibrational quantum. More pragmatically, the vibrational dynamics appear to be dominated by the bending vibrations, i.e., by the slowest oscillators.     

Intensity measurements in freon bands of atmospheric interest

The absolute intensities of the i.r. absorption bands, which are located in the atmospheric window region, of CFCl₃ (“Freon-11”) and CF₂Cl₂ (“Freon-12”) have been measured at 300°K. Our best estimates for these parameters are: for CFCl₃ (“Freon-11”), S_v = 635±36 cm^-2atm^-1 (9.2μ band), S_v = 1536±45 cm^-2atm^-1 (11.8μ band); for CF₂Cl₂ (“Freon-12”), S_v = 718±14 cm^-2atm^-1 (8.7μ band), S_v = 1136±22 cm^-2atm^-1 (9.1μ band), and S_v = 1302±40 cm^-2atm^-1 (10.9μ band).     

High-resolution infrared spectrum of acetylene in the region of the bending fundamental v 5

The infrared spectrum of C₂H₂ in the region of the bending fundamental v ₅ has been studied at a resolution of about 0·015 cm^-1. The molecular constants G ₀(v ₅=1) = 730·3341 (1) cm^-1 and B ₀ = 1·176641 (2) cm^-1 have been derived. In addition to the fundamental, all the hot bands starting from the levels v ₄ and v ₅ have been investigated. The vibrational, vibration-rotation coupling and centrifugal constants for the excited vibrational states v ₅ = 2 and v ₄ = v ₅ = 1 have been derived using the vibration-rotation energy matrix.     

态—态振动能量跃迁的时间分辨研究(Ⅰ)——碘分子的自碰撞过程

本文介绍了采用可调脉冲激光技术和时间分辨色散荧光方法研究态-态碰撞动力学的实验过程。在实验中直接观测了处于电子振动激发态B³Π_ou⁺(v＇=19)的碘分子在自碰撞事件中朝相邻振动态跃迁的衰变过程,得到态—态振动跃迁速率常数,k_v(19→18)=(2.21±0.33)×10^-11cm³s^-1mol^-1和k_v(19 关键词：     

The perpendicular fundamental v5 of chloroform 12CH35Cl3: high resolution infrared study of the v5 band together with the millimetre-wave rotational spectrum

The infrared spectrum of the perpendicular fundamental v₅ of chloroform around 776 cm^?1 has been studied by applying two high resolution methods. A short range from the central part of the spectrum was measured with a diode laser by using a cold jet sample including chloroform in natural isotopic abundancies. More than 100 rotational lines of ¹²CH³⁵Cl₃ could be assigned. The whole band region was measured by a Fourier transform spectrometer at a resolution of 0.0010cm^?1. In this case an isotopically pure sample of ¹²CH³⁵Cl₃ was used. Starting from the results of the diode laser investigation more than 2000 lines could be assigned with J_max = 91 and K_max = 58. In addition to the infrared spectra, millimetre-wave lines also were measured. A total of 58 lines corresponding to J values 22, 23 and 35 at the excited vibration state v₅ = 1 were assigned and analysed. All the data from three different spectra were simultaneously fitted and, for example, the results v₀ = 775.961 50(3) cm^?1, 98, B₅-B₀ = ?0.180171(22) × 10^?3cm^?1, C₅ ? C₀ = ?0.170 57(15) × 10^?3cm^?1, and (Cζ)₅ = 0.047 5294(11) cm^?1 were obtained.