High-Resolution Spectroscopic Investigation of the CHCHO Radical in the Sub-Millimeter Region.

In this work, the pure rotational spectrum of the vinoxy radical (CHCHO) has been studied at millimeter and sub-millimeter wavelengths (110-860 GHz). CHCHO was produced by H-abstraction from acetaldehyde (CHCHO) using atomic fluorine in a double-pass absorption cell at room temperature. A Zeeman-modulation spectrometer, in which an external magnetic field generated inside the absorption cell is amplitude-modulated, was used to record the pure rotational transitions of the radical.

Frequency stable and low phase noise THz synthesis for precision spectroscopy.

We present a robust approach to generate a continuously tunable, low phase noise, Hz linewidth and mHz/s stability THz emission in the 0.1 THz to 1.4 THz range.

Formation of the methyl cation by photochemistry in a protoplanetary disk.

Forty years ago, it was proposed that gas-phase organic chemistry in the interstellar medium can be initiated by the methyl cation CH (refs. ), but so far it has not been observed outside the Solar System. Alternative routes involving processes on grain surfaces have been invoked.

Searches for bridged bicyclic molecules in space-norbornadiene and its cyano derivatives.

The norbornadiene (NBD) molecule, CH, owes its fame to its remarkable photoswitching properties that are promising for molecular solar-thermal energy storage systems. Besides this photochemical interest, NBD is a rather unreactive species within astrophysical conditions and it should exhibit high photostability, properties that might also position this molecule as an important constituent of the interstellar medium (ISM)-especially in environments that are well shielded from short-wavelength radiation, such as dense molecular clouds. It is thus conceivable that, once formed, NBD can survive in dense molecular clouds and act as a carbon sink.

A rotational investigation of the three isomeric forms of cyanoethynylbenzene (HCC-CH-CN): benchmarking experiments and calculations using the "Lego brick" approach.

We report the study of three structural isomers of phenylpropiolonitrile (3-phenyl-2-propynenitrile, CH-CN) containing an alkyne function and a cyano group, namely -, -, and -cyanoethynylbenzene (HCC-CH-CN). The pure rotational spectra of these species have been recorded at room temperature in the millimeter-wave domain using a chirped-pulse spectrometer (75-110 GHz) and a source-frequency modulation spectrometer (140-220 GHz). Assignments of transitions in the vibrational ground state and several vibrationally excited states were supported by quantum chemical calculations using the so-called "Lego brick" approach [A.