ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The ion–molecule complex, Mg+–N2 is formed in a supersonic expansion and studied with mass-selected photodissociation spectroscopy. The lowest energy bands observed in the electronic excitation spectrum are redshifted more than 12 000 cm−1 from the Mg+ (2P←2S) atomic transition at 280 nm. The red-shift, resulting from differential bonding in the ground and excited states of the complex, is much larger than the shifts observed in previously studied Mg+–ligand complexes. Resolved vibronic structure is observed extending for more than 5000 cm−1. The observation of spin–orbit multiplet structure indicates that the complex is linear and that the electronic transition is 2Π←X 2Σ+. The spin–orbit splitting of 46 cm−1 is significantly less than that observed for other Mg+–L complexes. Vibronic intervals of about 1000 and 500 cm−1 are assigned respectively to a stretching mode and to double quanta in a bending mode. The study of isotopically substituted complexes indicates that the best assignment for the stretch progression is the N–N mode, with a frequency far below that in free N2. The vibrational activity, frequency shift, and spin–orbit splitting are all signatures for N2 activation by the excited metal ion. However, the degree of this interaction is greater than that predicted by ab initio calculations. © 1995 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.468880
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