The B2Σ+ state of zinc deuteride

Conventional high-resolution photographic spectroscopy has been employed to study the B²Σ-X²Σ emission system of zinc deuteride in the region 280–370 nm. The B-X system of ZnD is reported for the first time and 17 such bands have been rotationally analyzed. Many local rotational perturbations have been found in the B state and are attributable to interactions with the A²Π state. The rotational and vibrational data for ZnH (after Stenvinkel) and ZnD are complementary and enable the RKR curve for the B state to be mapped with reasonable accuracy for almost 10 000 cm⁻¹. B-X Franck-Condon factors for ZnH and ZnD are also reported.     

Intensity perturbation in the B2Σ-X2Σ band system of SrF

The intensity anomaly of the B²Σ-X²Σ system of SrF was analyzed based on the interaction between the A²Π and B²Σ states. The theoretical relative intensity was calculated from overlap integrals and spectroscopic constants previously obtained. Comparison between theoretical and observed intensities showed that the electronic transition moment of the B-X system is the same order of magnitude as that of the A-X system.     

TheB 2Σ-X 2Σ system of the CaF molecule

The spectrum of theB ²Σ-X ²Σ system of the CaF molecule has been photographed in the second order of a 10.6 m concave grating spectrograph with 0.33 Å/mm dispersion. The rotational structure of the (0, 0) and (1, 0) bands has been analysed and the precise molecular constants have been obtained. Using the constants so determined the band origins of a large number of bands with 0 <v′,v″ < 10 have been calculated and used to obtain the accurate vibrational constants forB andX states and these are presented.     

Rotational analyses of the A1Π-X1Σ+ and the a3Π-X1Σ+ systems of AlBr

The absorption spectrum of the A¹Π-X¹Σ⁺ system and the emission spectrum of the a³Π-X¹Σ⁺ system of AlBr have been examined at higher resolution than previously used. The present study has produced a significantly improved set of molecular constants for these excited states of AlBr. All data have been fitted in a self-consistent manner for an optimum set of constants. The broadening of features in the A-X system has been attributed to type c⁺ predissociation in the A¹Π state. Also, a comparison is made between the emission and absorption spectra of the A-X system.     

High resolution Fourier transform spectrum of GaCl

The electronic emission spectrum of the A³Π₀-X¹Σ⁺ and B³Π₁-X¹Σ⁺ transitions of Gallium monochloride molecule (⁶⁹GaCl) has been recorded on BOMEM DA8 Fourier transform spectrometer at an apodized resolution of 0.035 cm⁻¹. The rotational structure of the 0-0, 1-0, 2-1, and 3-2, bands belonging to A-X and 0-0, 0-1, 1-2, and 0-2 bands belonging to B-X transitions has been analyzed and equilibrium rotational constants for the X¹Σ⁺ and A³Π₀ states have been obtained. For the first time we are able to determine the Λ-doubling constants in the v = 0 and 1 levels of the B³Π₁ state.     

New spectroscopic studies of the Comet-Tail (AΠi-XΣ) system of the CO molecule

In the electronic emission spectrum of the ¹²C¹⁶O⁺ molecule, 11 bands of the Comet-Tail (A²Π_i-X²Σ⁺) system have been recorded and analyzed. Spin splitting in most of the observed lines of the 0-2, 1-0, 2-0, 2-1, 3-0, 4-0, 4-2, 6-0, 7-0, 7-1, and 8-1 bands, comprising nearly 3400 lines, has been recorded under high resolution by conventional spectroscopy. The rotational analysis of bands has been performed by nonlinear least-squares procedures and by means of effective Hamiltonians of Brown et al. and the rovibronic structure parameters have been obtained. The data of bands of the A-X system and earlier analyzed bands of the B-X and B-A systems have been merged together. As a result of this global fit, the state of information about the energy structure has been significantly enlarged for the A state and enlarged and improved for the X state. Also RKR potential curves for both states and Franck-Condon factors as well as r-centroids of the Comet-Tail system of CO⁺ have been calculated.     

Analysis of the Comet-Tail (AΠi-XΣ) Bands of CO

In the electronic emission spectrum of the isotopic carbon monoxide ion ¹³C¹⁶O⁺ molecule, seven bands of the comet-tail (A²Π_i-X²Σ⁺) system have been recorded and analyzed. The spin splitting in most observed lines of the bands 1-0, 2-0, 3-0, 4-0, 5-0, 2-1, and 7-1 comprising over 1900 lines has been recorded under high resolution by using conventional spectroscopy. The rotational analysis of bands has been performed by nonlinear least-squares procedures and by means of effective Hamiltonians of Brown et al., the rovibronic structure parameters have been obtained. As a result of multistaged and merged analysis of the currently obtained bands of the A-X system and of the bands of the B-X system obtained earlier the state of information about the energy structure has been significantly enlarged for the A state and enlarged and improved for the X state. Also RKR potential curves have been calculated for both states and Franck-Condon factors as well as r-centroids of the comet-tail system of ¹³C¹⁶O⁺.     

A1Σu+-X1Σg+ and B1Πu-X1Σg+ fluorescence of 6Li2 and 6Li7Li excited by a krypton ion laser

The A¹Σ_u⁺-X¹Σ_g⁺ and B¹Π_u-X¹Σ_g⁺ fluorescence of the ⁶Li₂ and ⁶Li⁷Li molecules has been studied for all krypton ion laser lines (468.0–799.3 nm) which might be expected to excite such fluorescence. Only two A-X fluorescence series of ⁶Li₂ were found (one excited by 647.1 nm, and one by 752.5 nm). No A-X fluorescence series of ⁶Li⁷Li was found. Five B-X fluorescence series of ⁶Li₂ were found (one each excited by 468.0, 476.2, and 530.9 nm, and two by 568.2 nm). Four B-X fluorescence series of ⁶Li⁷Li were found (one each excited by 468.0 and 482.5 nm and two by 520.8 nm). Calculated Einstein A coefficients and lifetimes for these transitions are also given.     

Laser-induced fluorescence and inelastic collisions of KH molecule

The laser-induced fluorescence spectrum of KH vapor, excited by the 4881-Å argon ion laser line, was obtained and analyzed. The transition was found to involve the A¹Σ⁺ and X¹Σ⁺ states. Vibrational and rotational energy transfer is detected. The spectrum presents a clear differentiation of bandheads. The molecular constants obtained are in good agreement with the previously reported data.     

The 1Σ+-X1Σ+ transition of the PN molecule

The recently observed ¹Σ⁺-X¹Σ⁺ transition of the PN molecule (J. Phys. B.13, 2251–2254 (1980)) has been photographed at high dispersion in the 1600–1900-Å region. A rotational analysis is carried out and shows 11 vibrational levels of the new ¹Σ⁺ state. These levels are perturbed and absolute vibrational numbering cannot be determined. Some perturbations can be accounted for by interactions with the A¹Π state. Weakening of lines are explained as accidental predissociations and allow us to discuss the dissociation energies of the X¹Σ⁺ and A¹Π states.     

Electron impact induced fluorescence of dissociating fragments from jet-cooled methane,methanol and ethanol

Dissociation fragments, following 20 keV electron impact on supersonic jet targets of methane, methanol and ethanol, have been analysed to determine rotational temperatures. The intensities of individual rotational lines of the CH A² Δ-X²Π, CH B²∑^- -X²Π and CH⁺A¹ Π-X¹∑⁺ transitions were measured and fitted to Boltzmann distributions. The temperatures obtained were about 4000 K for the CH A-X, 2000 K for the B-X and 1650 K for the CH⁺A-X transitions. The recorded spectra showed distributions at single temperatures. The intensities were also fitted to theoretical distributions in order to obtain excess energies. Possible fragmentation mechanisms are discussed.     

Measurements of temperatures and OH-concentrations in a lean methane-air flame using high-resolution laser-absorption spectroscopy

Line profile measurements of selected spectral lines in the 1-0 band of the A²Σ⁺-X²π system of OH near 2830 Å, using a tunable, frequency-doubled dye laser, have been made to determine simultaneously the translational temperature and hydroxyl concentration in a laminar, flat methane-air flame. The rotational temperature was determined from the ratio of two line-absorption coefficients. The rotational degree of freedom was found to be in equilibrium with the translational degree of freedom. Values deduced for the collision broadening parameter in the 1-0 band depend on OH-concentration, ground state rotational quantum number and, possibly, on the vibrational quantum number.     

Absorption spectrum of C2 molecules near 1.06 μm

An intracavity laser spectrometer has been used to study the laser-spark absorption spectrum of C₂ radicals near 1.06 μm. The spectra recorded have been assigned, and the rotational lines of the transitions 3-0, 4-1, and 5-2 b ³Σ _g ^? -a ³Π _u and 2-1 and 1-0 A ¹Π _u -X ¹Σ _g ⁺ have been identified. The vibrational and rotational temperatures have been determined.     

C2H221分子转动角动量定向分布(Orientation)及其碰撞弛豫和转移

利用圆偏振激光受激Raman抽运,以 C₂H₂分子为样品选择性地制备了它的电子基态单一转动态(X¹Σ⁺_g,ν″₂＝1,J″的角动量定向布居(orientation)．并从圆偏振紫外激光诱导的A¹A_u(ν′₃＝1)←X¹Σ⁺_g(ν″₂＝1)的荧光（谱）,直接测定了 C₂H₂(X¹Σ^＋_g,ν″₂＝1,J″＝4,7,8,…,13）的角动量定向布居值．从时间分辨的荧光信号谱测定了角动量定向布居的碰撞弛豫速率常数,同时还研究了由各初始激励的转动态向其他邻近转动态碰撞诱导的角动量定向布居转移． 关键词：     

The laser-induced fluorescence of IBr79

Four fluorescence progressions of the B0⁺-X¹Σ⁺ band of IBr⁷⁹ excited by a single-mode cw dye-laser have been observed and analyzed. Discrepancies in the reported rotational constants of the ¹Σ⁺ state have been resolved and improved vibrational constants determined. A simple method of discriminating between IBr and interfering I₂ fluorescence is described.     

Fourier transform spectroscopy of the A3Π-X3Σ− transition of NH

The A³Π-X³Σ⁻ transition of NH has been observed using a high-resolution Fourier transform spectrometer. The first three vibrational levels in each state were observed and the vibrational, fine structure, and rotational constants obtained.     

Rotational distribution in simultaneously excited electronic states of NH

The rotational structures of the NH(A³Π→X³Σ^-) and (c¹Π→a¹Δ) bands were excited simultaneously in electrical discharges through NH₃ and NH₃ + Ar. The A³Π state exhibits higher rotational temperature than the c¹Π state. The NH (A³Π) excited in an NH₃ + Ar discharge showed non-Maxwellian distribution. Mechanisms for excitation of NH are discussed.     

The ultraviolet absorption spectra of GeO in rare gas matrices

The absorption spectra of GeO isolated in rare gas matrices have been investigated in the wavelength region 1150–3000 Å using the 2.5-GeV synchrotron in Bonn as a continuum light source. Two vibrational progressions of bands have been found in each of the matrices, in neon, argon, krypton, and xenon. These progressions are situated in the regions 2400–2700 and 1800–2100 Å. They have been analyzed as corresponding to gas-phase bands of the A¹Π-X¹Σ⁺ and the E¹Σ⁺-X¹Σ⁺ systems, respectively. Absorption lines of matrix-isolated GeO were also found in the region 1180–1500 Å.     

Extension of the A1Σ+-X1Σ+ system of7LiH near the dissociation limit

The absorption spectra of⁷LiH have been photographed in the 3,500?2,900 Å region using the second order of a 3.4 M Ebert spectrograph. Observations comprise previously observedA ¹ Σ ⁺-X ¹ Σ ⁺ transitions and several new vibrational bands of this system near the ionisation limit. Rotational and vibrational analysis of these bands (16≦V′≦20) have been carried out and the rotational constants for the upper states have been determined.