Knowledge Bank

Hydrazine is found to react with alkaline earth metal vapors, producing visible chemiluminescence. Dispersed light from the orange, red and green flames produced by calcium, strontium and barium, respectively, show visible and near infrared features strikingly similar to the spectra of the corresponding alkaline earth hydroxides and fluorides. This spectral correlation and the fact that identical (although less intense) chemiluminescence is produced by the metal-ammonia flames, suggest that in each case the emitter is an isoelectronic alkaline earth monoamide, $MNH2$. A discussion of the electronic structure and bonding in this molecular class will be presented.