When high-energy radiation passes through aqueous material, low-energy electrons are produced which cause DNA damage. Electronic states of anionic nucleobases have been suggested as an entrance channel to capture the electron. However, identifying these electronic resonances restricted gas-phase electron-nucleobase studies and offer limited insight into available within environment DNA. Here, resonance detachment energies micro-hydrated uracil pyrimidine nucleobase anion determined by...

Coulomb explosion velocity-map imaging is a new and potentially universal probe for gas-phase chemical dynamics studies, capable of yielding direct information on (time-evolving) molecular structure. The approach relies detailed understanding the mapping between initial atomic positions within structure interest final velocities fragments formed via explosion. Comprehensive on-the-fly ab initio trajectory studies are presented two prototypical small molecules, formyl chloride...

This collaboration has recently shown that infrared excitation can drive decomposition reactions of molecules on the surface gas-phase transition metal clusters. We describe here a significant extension this work to study bimolecular initiated in similar manner. Specifically, we have observed activated CO oxidation reaction (CO(ads) + O(ads) --> CO2(g)) isolated platinum oxide cations, Pt(n)O(m)+. Small cluster oxides Pt(n)O(m)+ (n = 3-7, m 2, 4), been decorated with and subjected multiple...

Neutral metal-containing molecules and clusters present a particular challenge to velocity map imaging techniques. Common methods of choice for producing such species as laser ablation or magnetron sputtering typically generate wide variety and, without the possibility mass-selection, even determining identity dissociating moiety can be challenging. In recent years, we have developed spectrometer equipped with source explicitly studying neutral species. Here, report results...

The near ultraviolet photodissociation dynamics of silver atom—rare gas dimers have been studied by velocity map imaging. Ag–RG (RG = Ar, Kr, Xe) species generated laser ablation are excited in the region C (2Σ+)←X (2Σ+) continuum leading to direct, near-threshold dissociation generating Ag* (2P3/2) + RG (1S0) products. Images recorded at excitation wavelengths throughout continuum, coupled with known atomic energy levels, permit determination ground X state energies 85.9 ± 23.4 cm−1...

The combination of halogen- and hydrogen-bonding capabilities possessed by 4-bromopyrazole 4-iodopyrazole has led to them being described as "magic bullets" for biochemical structure determination. Laser vaporisation was used introduce each these 4-halopyrazoles into an argon gas sample undergoing supersonic expansion prior the recording rotational spectra molecules chirped-pulse Fourier transform microwave spectroscopy. Data were obtained four isotopologues two 4-iodopyrazole. Isotopic...

The Coulomb explosion dynamics following strong field ionization of chlorocarbonylsulfenyl chloride was studied using multimass coincidence detection and covariance imaging analysis, supported by density functional theory calculations. These results show evidence multiple dissociation channels from various charge states. Double to low-lying electronic states leads a dominant C–S cleavage channel, while higher can alternatively correlate the loss Cl+. Triple double observation which is...

The Coulomb explosion (CE) of jet-cooled CH3I molecules using ultrashort (40 fs), nonresonant 805 nm strong-field ionization at three peak intensities (260, 650, and 1300 TW cm-2) has been investigated by multimass velocity map imaging, revealing an array discernible fragment ions, that is, Iq+ (q ≤ 6), CHn+ (n = 0-3), CHn2+ 0, 2), C3+, H+, H2+, H3+. Complementary ab initio trajectory calculations the CE CH3IZ+ cations with Z 14 identify a range behaviors. parent 2 3 can be well-described...

Rotational spectra have been measured and assigned for four conformers of<italic>trans</italic>-urocanic acid.

Abstract The effect that solvation has on electron attachment to uracil, U, was studied by probing the electronic resonances of uracil radical anion, U − , in gas-phase water clusters, (H 2 O) n using photoelectron imaging across a range photon energies. Specifically, π 3 * shape resonance probed detail and spectral signatures following excitation this are considered. Several new methods for analysis provided capture different actions emission, which turn provide insight into location its...

The dynamics of photoinduced O-H bond fission in five fluorinated phenols (2-fluorophenol, 3-fluorophenol, 2,6-difluorophenol, 3,4,5-trifluorophenol, and pentafluorophenol) have been investigated by H Rydberg atom photofragment translational spectroscopy following excitation at many wavelengths the range 220 ≤ λ 275 nm. presence multiple fluorine substituents reduces efficiency (by tunneling) from first excited (11ππ*) electronic state, whereas all bar perfluorinated species undergo when...

The ultraviolet (UV) photodissociation of gas-phase methimazole has been investigated by H Rydberg atom photofragment translational spectroscopy methods at many wavelengths in the range 222.5–275 nm and complementary electronic structure calculations. Methimazole is shown to exist predominantly as thione tautomer, 1-methyl-2(3H)-imidazolinethione, rather than commonly given thiol form, 2-mercapto-1-methylimidazole. UV absorption spectrum dominated S4 ← S0 transition which involves electron...

Coupling covariance map analysis with ultrafast laser-induced Coulomb explosion imaging (CEI) enabled us to characterise the dissociative ionisation dynamics of methoxycarbonylsulfenyl chloride (H3COCOSCl). We applied a 3D multi-coincidence detection technique which is necessary for analysis. With aid such analysis, we found meaningful correlations between several product ion pairs that revealed different fragmentation channels. A weak, narrow correlation in image H3COC(O)+/Cl+ was assigned...

The rotational spectra complexes of argon-urea, argon-thiourea and water-thiourea have been measured by chirpedpulse Fourier transform microwave spectroscopy from 2-18.5 GHz.The sample was produced via laser vaporisation a rod containing copper the organic as stream argon passed over surface subsequently expanded into vacuum chamber cooling sample.Argon found to bind π system carbonyl bond for both urea thiourea complexes.

The microwave spectra of two isomers iodoimidazole have been recorded and assigned with resolution their nuclear quadrupole coupling constants.These constants analysed in terms the conjugation between lone pairs on iodine atom aromatic π-bonding system, effect this distribution πelectron density ring.A comparison these properties has made other 5-and 6-membered rings bonded to halogen atoms.

Ground state radical dissociation pathways of HDCO were investigated. Frequencies rovibrational lines from a variety vibrational bands the first singlet excited over broad excitation energy range determined and subsequently used to excite singly deuterated formaldehyde, HDCO. Translational release H D atoms measured by velocity map imaging was then determine accurate threshold energies 30,448 ± 5 cm−1 for + DCO 30,949 3 HCO.