Probing the Electronic Manifold of MgCl with Millimeter-Wave Spectroscopy and Theory: (3)Σ and (4)Σ States.

The millimeter/submillimeter spectrum of magnesium chloride (MgCl) has been observed in two new electronic excited states, (3)Σ and (4)Σ, using direct absorption methods. The molecule was synthesized in a mixture of Cl, argon, and magnesium vapor. For the (3)Σ state, multiple rotational transitions were measured in the = 0 level for all six isotopologues (MgCl, MgCl, MgCl, MgCl, MgCl, and MgCl), as well as up to = 13 for MgCl.

Prebiotic Astrochemistry from Astronomical Observations and Laboratory Spectroscopy.

The discovery of more than 200 gas-phase chemical compounds in interstellar space has led to the speculation that this nonterrestrial synthesis may play a role in the origin of life. These identifications were possible because of laboratory spectroscopy, which provides the molecular fingerprints for astronomical observations. Interstellar chemistry produces a wide range of small, organic molecules in dense clouds, such as NHCOCH, CHOCH, CHCOOCH, and CH(OH)CHO.

Phosphorus-bearing molecules PO and PN at the edge of the Galaxy.

Despite its importance in planet formation and biology, phosphorus has been identified only in the inner 12 kpc of the Galaxy. The study of this element has been hindered in part by unfavourable atomic transitions. Phosphorus is thought to be created by neutron capture on Si and Si in massive stars, and released into the interstellar medium by Type II supernova explosions.

The millimeter-wave spectrum of the SiP radical (XΠ): Rotational perturbations and hyperfine structure.

The millimeter/submillimeter-wave spectrum of the SiP radical (XΠ) has been recorded using direct absorption spectroscopy in the frequency range of 151-532 GHz. SiP was synthesized in an AC discharge from the reaction of SiH and gas-phase phosphorus, in argon carrier gas. Both spin-orbit ladders were observed.