Electronic spectrum of the hydrocarbon cation

Abstract

A high-resolution gas-phase electronic spectrum has been detected in the 408 nm region using a cw cavity ring-down spectrometer. The absorption band system is observed using a pulsed slit nozzle discharge with a mixture of acetylene in argon. The rotationally resolved spectrum obtained is that of a symmetric top molecule. The determined constants are ν = 24491.0500 (108) and B′′ = 0.14165 (44) cm⁻¹. Consideration of the latter value and ab initio calculations leads to the assignment ³E ← X ³E transition of the linear carbon chain species in the triplet ground electronic state with C_3v symmetry.

Acknowledgements

This work has been supported by the Swiss National Science Foundation (project 200020-107386) and is part of the European Union project ‘Molecular Universe’ (MRTN-CT-2004-512302).

Notes

‡Present address: PALMS-UMR 6627 du CNRS, Université de RENNES 1, Campus de Beaulieu, 35042 RENNES Cedex, France.

Additional information

Notes on contributors

P. Birza‡

‡Present address: PALMS-UMR 6627 du CNRS, Université de RENNES 1, Campus de Beaulieu, 35042 RENNES Cedex, France.