The reactions between chromium atoms and acetylene have been investigated in solid argon with infrared absorption spectroscopy. It is found that the ground-state chromium atoms reacted with acetylene to form the metallocyclopropene Cr(C2H2) molecule spontaneously on annealing. The Cr(C2H2) molecule underwent photochemical rearrangement to the alkynyl hydride HCrCCH molecule upon ultraviolet−visible irradiation. The two products were identified on the basis of isotopic IR studies with 13C2H2 and C2D2, and density functional theory calculations.

This report presents the preparation and characterization of H2OOO+, an important intermediate in water-oxygen chemistry. The H2OOO+ cation was produced by co-deposition of H2O/Ar with radio frequency discharged O2/Ar at 4 K and was identified by four fundamental infrared absorptions. Quantum chemical calculations indicate a doublet ground state with a H2O-O2 hemi-bonded Cs structure.

When a high-frequency discharged CS 2 :O 2 :Ar sample was condensed at 4 K, new absorptions at 1003.1 and 567.7 cm -1 were produced. Isotopic substitution ( 13 CS 2 /O 2 , C 34 S 2 /O 2 , CS 2 / 18 O 2 , and mixtures) shows that these new absorptions are due to S-O and S-S stretching vibrations, which involve two inequivalent S atoms and one O atom. The photosensitive behavior and the agreement with frequencies and isotopic frequency ratios from quantum chemical calculations substantiate assignment of these absorptions to the SSOanion, which was predicted to have a bent structure with elongated S-S and S-O bond lengths relative to those of S 2 O.

Employing tidally enhanced stellar wind, we studied in binaries the effects of metallicity, mass ratio of primary to secondary, tidal enhancement efficiency and helium abundance on the formation of blue hook (BHk) stars in globular clusters (GCs). A total of 28 sets of binary models combined with different input parameters are studied. For each set of binary model, we presented a range of initial orbital periods that is needed to produce BHk stars in binaries. All the binary models could produce BHk stars within different range of initial orbital periods. We also compared our results with the observation in the T eff -logg diagram of GC NGC 2808 and ω Cen. Most of the BHk stars in these two GCs locate well in the region predicted by our theoretical models, especially when C/N-enhanced model atmospheres are considered. We found that mass ratio of primary to secondary and tidal enhancement efficiency have little effects on the formation of BHk stars in binaries, while metallicity and helium abundance would play important roles, especially for helium abundance. Specifically, with helium abundance increasing in binary models, the space range of initial orbital periods needed to produce BHk stars becomes obviously wider, regardless of other input parameters adopted. Our results were discussed with recent observations and other theoretical models.