Yasushi Ozaki

Analysis of the B2Σ+ ∼ A2Πi perturbations in the CN(B2Σ+-X2Σ+) main band system: I. Molecular constants for B2Σ+ and A2Πi

Abstract The CN( B 2 Σ + - X 2 Σ + ) main band transitions (0 ≤ v ′ ≤ 9) observed by H. S. Uhler and R. A. Patterson were assigned, and a number of local perturbations between the B 2 Σ + , v = 0–9 and A 2 Π i , v = 11–24 levels occurring at 30 ≲ J ′ ≲ 140 were analyzed. The molecular constants for the B 2 Σ + and A 2 Π i states including the higher-order centrifugal distortion constants, E v , B v , D v , H v , Δ L v , Δ M v , and Δ N v , were determined, where Δ represents the difference between the constants for the B 2 Σ + and X 2 Σ + states. The CN( B 2 Σ + - X 2 Σ + ) 0-0 band observed by R. Engleman was also reanalyzed, and the perturbation constants for the B 2 Σ + , v = 0 ∼ A 2 Π i , v = 10 perturbation were redetermined. The electronic terms of the interaction matrix elements, H el SO and H el RE , determined in the present study were found to be nearly constant and in good agreement with those determined in our previous analysis of the CN( B 2 Σ + - X 2 Σ + ) system.

Rotational perturbations in the CN (B 2Σ+-X 2Σ+) tail band system. I. Analysis of the υ = 27 and 30 levels of CN (A 2Πi)

Abstract The perturbed rotational lines observed in the CN(B 2 Σ + -X 2 Σ + ) 12-12 and 14-14 bands are assigned. The vibrational levels, the rotational constants, and the spin—orbit interaction constants of the perturbing states, CN(A 2 Π i ) υ = 27 and 30, are determined. An RKR potential for the CN(A 2 Π i ) state is obtained up to υ = 30, and an approximate RKR potential is estimated by extrapolation up to the dissociation limit, υ = 61. The electronic terms of the perturbation constants between the CN(A 2 Π i ) and CN(B 2 Σ + ) states, H cl SO and H cl RE , are determined for (υ A , υ B ) = (24, 10), (27, 12) and (30, 14). These constants are found to be nearly equal to the corresponding constants governing the interaction between the N 2 + (A 2 Π u ) and N 2 + (B 2 Σ u + ) states.

Rotational perturbations in the CN (B 2Σ+-X 2Σ+) tail band system. II. Identification of the CN (4Π) state and its vibrational levels

Abstract The intensity anomalies observed in the 12-12 ( N = 10), 14-14 ( N = 7, 10), and 17-14 ( N = 17, 19) lines of the CN violet bands are found to be due to rotational perturbations by the CN ( 4 Π) state. Experimental evidence that the perturbing state is 4 Π, predicted theoretically by Schaefer and Heil, is presented, and the spectroscopic constants of this state are estimated.

Analysis of anomalous vibrational and rotational distributions in the CN(B2Σ+) state produced in the reaction of Ar(3P0,2) metastables with BrCN

Abstract The CN(B 2 Σ + - X 2 Σ + ) tail band emission system for μ′ = 11–20 resulting from the energy transfer reaction Ar( 3 P 0,2 ) + BrCN in a flowing afterglow apparatus was measured. The vibrational and rotational distributions were determined as a function of argon pressure. Numerous perturbed rotational lines were observed; analysis of the dependences of these lines on argon pressure, with the aid of experimental information already published, led to the following assignments as to the origins of the perturbations: For μ′ = 11, N′ = 20 and μ′ = 13, N′ = 9, the perturbing state is a 4 Σ + ; for μ′ = 12, N′ = 10 and 14, μ′ = 14, N′ = 7 and 10, and μ′ = 17, N′ ≈ 17–19 the perturbing state is A 2 Π i . The perturbed rotational line, μ′ = 11, N′ = 20, is found to be the primary source of intensity in the μ′ =11 vibrational band, but in all other cases the perturbed rotational lines do not significantly aid in the populating of the vibrational state. The anomalously high vibrational populations found in the tail band emission system (μ′ = 12, 14, 17 and 18), as well as the significantly high rotational excitations observed in the μ′ = 12–20 vibrational bands, apparently arise directly from the reaction intermediate.

Absorption spectra of hydrogen cyanide and deuterium cyanide in the 130-80 nm range

Abstract The absorption spectra of HCN and DCN were measured from 130 to 80 nm. Strong absorption bands were observed below 122 nm both for HCN and DCN. These bands were assigned to the Rydberg series converging to the first and the second ionization potentials and to valence transitions at about 120 and 115 nm. The absorption coefficients for HCN were determined over entire range studied. The maximum absorption coefficient, at 112.39 nm, was measured to be 2.8 × 10 3 cm −1 with an estimated uncertainty of about 20%.

Dynamics of formation of CN(B2Σ+) fragment from HCN and DCN in an argon afterglow

Abstract The dissociative excitation of HCN and DCN producing CN(B2Σ+) in collision with Ar(3P0,2) was investigated in a flowing afterglow. The Δν = 0, −1, and −2 sequences of the CN(Bue5f8X) violet emission were analyzed by computer simulation, and the vibrational and rotational distributions of the CN(B2Σ+) fragment were obtained. Possible reaction pathways were studied on the basis of a linear surprisal analysis of the observed distributions and their isotope effects.

Analysis of the B2Σ+ ∼ A2Πi perturbations in the CN(B2Σ+ - X2Σ+) main band system: Electronic structures of B2Σ+ and A2Πi

Abstract The Λ-doubling constants for the CN(A2Πi) state are estimated by the second-order perturbation theory by use of the matrix elements of the electronic interactions, HelSO (spin-orbit) and HelRE (rotational-electronic), for the B2Σ+ ∼ A2Πi and X2Σ+ ∼ A2Πi perturbations. The Λ-doubling constants are compared with those determined experimentally by Kotlar et al. The HelSO term of the B2Σ+ ∼ A2Πi perturbation is found to depend strongly on the internuclear distance, R. The R dependences of HelSO and the electronic part of the spin-orbit constant, A(R), for the A2Πi state determined in the preceding paper are found to originate from the R dependences of the A2Πi ∼ D2Πi and B2Σ+ ∼ E2Σ+ homogeneous interactions.

Calculation of the potential energy curves for the low-lying doublet and quartet states of the CN radical

Abstract The potential energy curves of the low-lying X2Σ+, A2πi, B2Σ+,4Σ+, and 4π states of CN are calculated by the MC SCF (CAS SCF) method. Their vibrational levels and the molecular constants obtained are in good agreement with those determined in our recent experimental analysis of the CN (B2Σ+-X2Σ+) emission spectrum. several intensity anomalies in the observed spectrum are ascribed to perturbations between the B2Σ+ and 4π states with the following vibrational quantum numbers: (υB, υπ)=(9,x), (11, x+2), (12, x+3), (14, x+6), (17, x+11), and (18, x+13), where x = 0 is the most probable assignment. Likewise, the perturbations between the B2Σ+ and 4Σ+ states with (υB, υΣ) = (11, y), (13, y+3) are interpreted as y = 8±1.

Energy-transfer reactions of metastable argon ions with krypton in a flowing afterglow

Abstract Light emissions were observed from Kr(6p) produced in the flowing-afterglow reaction of Kr with active ionic species of argon, which were ascribed to the metastable states. Ar+M. Relative quenching rates of ArM and Ar+M by Ar and N2 were examined: Ar quenches Ar+M more effectively than ArM, whereas N2 quenches ArM more effectively than Ar+M.

Analysis of perturbation between the B2Σ+, v = 5 and A2Πi, v = 17 levels of the CN radical

Abstract The B 2 Σ + , v = 5 ∼ A 2 Π i , v = 17 perturbation in CN was analyzed by a least-squares fit of the CN( B 2 Σ + - X 2 Σ + ) 5-4 and 5-5 bands reported by R. Engleman. By use of the various spectroscopic constants obtained in recent studies, the vibrational energies of the v B = 5 and v A = 17 levels, the B v , D v , and γ v constants for v B = 5, and the interaction constants of the perturbation, α and β, were determined as follows: E vB = 35 990.13(6) cm −1 , E vA = 36 011.0(6) cm −1 , B vB = 1.84548(36) cm −1 , D vB = 7.53(55) × 10 −6 cm −1 , γ vB = 1.99(21) × 10 −2 cm −1 , α = −2.37(14) cm −1 , and β = 0.221(19) cm −1 .