The D 5 Π–X 5 Δ (0,0) band of vanadium hydride at 654 nm has been recorded by laser excitation spectroscopy and represents the first analyzed spectrum of VH in the gas phase. The molecules were generated using a hollow cathode discharge source, with laser-induced fluorescence detected via the D 5 Π–A 5 Π (0,0) transition. All five main (ΔΩ = ΔΛ) subbands were observed as well as several satellite ones, which together create a rather complex and overlapped spectrum covering the region 15 180–15 500 cm −1 . The D 5 Π state displays the effects of three strong local perturbations, which are likely caused by interactions with high vibrational levels of the B 5 Σ − and c 3 Σ − states, identified in a previous multiconfigurational self-consistent field study by Koseki et al. [J. Phys. Chem. A 108, 4707 (2004)]. Molecular constants describing the X 5 Δ, A 5 Π, and D 5 Π states were determined in three separate least-squares fits using effective Hamiltonians written in a Hund’s case (a) basis. The fine structure of the ground state is found to be consistent with its assignment as a σπ 2 δ, 5 Δ electronic state. The fitted values of its first-order spin–orbit and rotational constants in the ground state are [Formula: see text] and B = 5.7579(13) cm −1 , the latter of which yields a bond length of [Formula: see text] Å. This experimental value is in good agreement with previous computational studies of the molecule and fits well within the overall trend of decreasing bond length across the series of 3d transition metal monohydrides.
more »
« less
High Spin Study of 104 Ag Nucleus
High spin states in 104 Ag were populated via heavy-ion ( 32 S) induced fusion evaporation reaction at a beam energy of 110 MeV. The de-exciting γ-rays were detected by 18 Compton suppressed HPGe clover detectors, placed in different (θ, φ) angles. Spin of several excited states were assigned firmly from the present angular correlation measurement.
more »
« less
- Award ID(s):
- 2011890
- NSF-PAR ID:
- 10335726
- Date Published:
- Journal Name:
- ECS Transactions
- Volume:
- 107
- Issue:
- 1
- ISSN:
- 1938-5862
- Page Range / eLocation ID:
- 12577 to 12584
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
The kinetic energy dependent reactions of Re + with SO 2 were studied with guided ion beam tandem mass spectrometry. ReO + , ReO 2 + , and OReS + species were observed as products, all in endothermic reactions. Modeling of the kinetic energy dependent cross sections yields 0 K bond dissociation energies (BDEs, in eV) of 4.78 ± 0.06 (Re + –O), 5.75 ± 0.02 (Re + –O 2 ), and 4.35 ± 0.14 (Re + –SO). The latter two values can be combined with other information to derive the additional values 6.05 ± 0.05 (ORe + –O) and 4.89 ± 0.19 (ORe + –S). BDEs of ReO + and ReO 2 + agree with literature values whereas the values for OReS + are the first measurements. The former result is obtained even though formation of ground state ReO + is spin-forbidden. Quantum mechanical calculations at the B3LYP level of theory with a def2-TZVPPD basis set yield results that agree reasonably well with experimental values. Additional calculations at the BP86 and CCSD(T) levels of theory using def2-QZVPPD and aug-cc-pVxZ (x = T, Q, and 5) basis sets were performed to compare thermochemistry with experiment to determine that ReO 2 + rather than the isobaric ReS + is formed. Product ground states are 3 Δ 3 (ReO + ), 3 B 1 (OReO + ), 5 Π −1 (ReS + ), and 3 A′′(OReS + ) after including empirical spin–orbit corrections, which means that formation of ground state products is spin-forbidden for all three product channels. The potential energy surfaces for the ReSO 2 + system were also explored at the B3LYP/def2-TZVPPD level and exhibited no barriers in excess of the endothermicities for all products. BDEs for rhenium oxide and sulfide diatomics and triatomics are compared and discussed. The present result for formation of ReO + is compared to that for formation of ReO + in the reactions of Re + + O 2 and CO, where the former system exhibited interesting dual cross section features. Results are consistent with the hypothesis that the distinction of in-plane and out-of-plane C S symmetry in the triatomic systems might be the explanation for the two endothermic features observed in the Re + + O 2 reaction.more » « less
-
Gamma-ray detection following the inelastic neutron scattering reaction on isotopically enriched material was used to study the nuclear structure of 74 Ge. From these measurements, low-lying, low-spin excited states were characterized, new states and their decays were identified, level lifetimes were measured with the Doppler-shift attenuation method (DSAM), multipole mixing ratios were established, and transition probabilities were determined. New structural features in 74 Ge were identified, and the reanalysis of older 76 Ge data led to the placement of the 2 + member of the intruder band. In addition, a number of previously placed states in 74 Ge were shown not to exist. A procedure for future work, which will lead to meaningful data for constraining calculations of the neutrinoless double-beta decay matrix element, is suggested.more » « less
-
The kinetic energy dependences of the reactions of Pt + ( 2 D 5/2 ) with SO 2 were studied using a guided ion beam tandem mass spectrometer and theory. The observed cationic products are PtO + and PtSO + , with small amounts of PtS + , all formed in endothermic reactions. Modeling the kinetic energy dependent product cross sections allows determination of the product bond dissociation energies (BDEs): D 0 (Pt + –O) = 3.14 ± 0.11 eV, D 0 (Pt + –S) = 3.68 ± 0.31 eV, and D 0 (Pt + –SO) = 3.03 ± 0.12 eV. The oxide BDE agrees well with more precise literature values, whereas the latter two results are the first such measurements. Quantum mechanical calculations were performed for PtO + , PtS + , PtO 2 + , and PtSO + at the B3LYP and coupled-cluster with single, double, and perturbative triple [CCSD(T)] levels of theory using the def2-XZVPPD (X = T, Q) and aug-cc-pVXZ (X = T, Q, 5) basis sets and complete basis set extrapolations. These theoretical BDEs agree well with the experimental values. After including empirical spin–orbit corrections, the product ground states are determined as PtO + ( 4 Σ 3/2 ), PtS + ( 4 Σ 3/2 ), PtO 2 + ( 2 Σ g + ), and PtSO + ( 2 A′). Potential energy profiles including intermediates and transition states for each reaction were also calculated at the B3LYP/def2-TZVPPD level. Periodic trends in the thermochemistry of the group 9 metal chalcogenide cations are compared, and the formation of PtO + from the Pt + + SO 2 reaction is compared with those from the Pt + + O 2 , CO 2 , CO, and NO reactions.more » « less
-
Hyperpolarization of 13 C-pyruvate via Signal Amplificaton By Reversibble Exchange (SABRE) is an important recent discovery because of both the relative simplicity of hyperpolarization and the central biological relevance of pyruvate as a biomolecular probe for in vitro or in vivo studies. Here, we analyze the [1,2- 13 C 2 ]pyruvate-SABRE spin system and its field dependence theoretically and experimentally. We provide first-principles analysis of the governing 4-spin dihydride- 13 C 2 Hamiltonian and numerical spin dynamics simulations of the 7-spin dihydride- 13 C 2 –CH 3 system. The analytical and the numerical results are compared to matching systematic experiments. With these methods we unravel the observed spin state mixing of singlet states and triplet states at microTesla fields and we also analyze the dynamics during transfer from micro-Tesla field to high field for detection to understand the resulting spectra from the [1,2- 13 C 2 ]pyruvate-SABRE system.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1149/10701.12577ecst
