The influence of a nitrogen atom in the backbone PAH was revealed by hydrated clusters phenanthrene and phenanthridine rotational spectroscopy study. Background image credit: NASA, ESA, Hubble Heritage Team (STScI/AURA) – ESA/Hubble Collaboration.

We report infrared multiple photon dissociation spectra of cryogenically-cooled (NaSO4(-))2(H2O)n dianions (n = 0-6, 8) in the spectral range of the sulfate stretching and bending modes (580-1750 cm(-1)). Characteristic absorption bands and structural trends are identified based on a comparison to harmonic spectra of minimum-energy structures. The bare quarternary complex (NaSO4(-))2 exhibits a...

In the course of metabolite formation, some multienzymatic edifices, the so-called metabolon, are formed and lead to a more efficient production of these natural compounds. One of the major features of these enzyme complexes is the facilitation of direct transfer of the metabolite between enzyme active sites by substrate channelling. Biophysical insights into substrate channelling remain scarce...

The microsolvation of cobalt and nickel dications by acetonitrile and water is studied by measuring photofragment spectra at 355, 532 and 560-660 nm. Ions are produced by electrospray, thermalized in an ion trap and mass selected by time of flight. The photodissociation yield, products and their branching ratios depend on the metal, cluster size and composition. Proton transfer is only observed...

Infrared (IR) photodissociation spectra of mass selected Arn-HN2 complexes (n ) 1-13) have been recorded in the 4 μm spectral range in a tandem mass spectrometer. The dominant features are assigned to the ν1 + mνs (m ) 1, 2) combination bands, where ν1 corresponds to the intramolecular N-H stretch mode and νs to the intermolecular stretching vibration of the first (proton-bound) Ar ligand. Syst...

Bcl-xL, a member of the Bcl-2 family of proteins, remains distributed over the cytosol and the mitochondrial membrane, maintaining a balance between apoptosis and the survival of the cell. Passage to the membrane is essential for its biological functions (e.g. to antagonize pro-apoptotic proteins of the Bcl2 family), which is known to be initiated by the insertion of the C-terminal segment into...

We have simulated ionization of purine nucleic acid components in the gas phase and in a water environment. The vertical and adiabatic ionization processes were calculated at the PMP2/aug-cc-pVDZ level with the TDDFT method applied to obtain ionization from the deeper lying orbitals. The water environment was modeled via microsolvation approach and using a nonequilibrium polarizable continuum m...

The results are presented of a theoretical study of the nitrosation chemistry of pyrroline 1 (X = CH2), imidazoline 2 (X = NH), and 2-oxazoline 3 (X = O). Imines 1-3 are converted to the alpha-hydroxy-N-nitrosamines 7-9 via the N-nitrosoiminium ions 4-6. The NN-cis isomers of 7-9 may undergo retro-ene reactions to the delta-oxoalkyl diazotic acids 10-12. With the opportunity for microsolvation,...

Mid-infrared photodissociation spectra of H2O-Arn (n ) 1-14) complexes have been recorded in the vicinity of the OsH stretch vibrations of the water cation. The rovibrational structure of the transitions in the dimer spectrum (n ) 1) are consistent with a planar, proton (H)-bound HsOsHsAr equilibrium geometry. The slightly translinear intermolecular bond in the ground vibrational state is chara...