Fischer, GadJohnson, G DanaRamsay, D ARoss, I2015-12-132015-12-131089-5639http://hdl.handle.net/1885/76405The 2800 Å forbidden1Σu- ←1Σg+ transition of dicyanoacetylene shows conventional vibronic origins due to the two πg vibrations and a third involving the lower πu vibration. For the latter we argue against a magnetic dipole mechanism and propose thaKeywords: Absorption spectroscopy; Electron energy levels; Magnetic properties; Molecular structure; Molecular vibrations; Organic compounds; Quantum theory; Dicyanoacetylene; Electronic spectrum; Magnetic dipole; Quantum numbers; Electron transitions200310.1021/jp034967b2015-12-11