Diatomic dications

Schwarz and coworkers258 have been successful in generating the diatomic dication SiF2+ by charge-stripping mass spectrometry (equation 43)259-262. 

M. Kolbuszewski and J. S. Wright, Can.. Cbem., 71, 1562 (1993). Predicting Thermodynamic Stability of Diatomic Dications A Case Study of BeF2. 

Ab Initio Valence Bond Description of Diatomic Dications ... 

An alternative model description of dication energy curves has been given by several groups 11 17>. Based directly on the VB method, this model attributes the origin of the barrier in the ground state energy curve of diatomic dications AB2+ to an avoided crossing between a purely repulsive covalent... 

As noted above, the helium diatomic dication has been well studied11 7,17,19,321. The standard three configuration VB wave function for the "singly-bonded" (He,-Heb)2+ consists of a linear combination of configurations (1) to (3) ... 

The He22+, 022+ and NF2+ diatomic dications have ground state energy curves that are characterized by a short equilibrium bond distance, an exothermic dissociation energy and a barrier to dissociation that bestows kinetic metastability on the dication. Due to their finite lifetimes all three dications have been detected experimentally. 

Therefore, as generally described by Pauling, the diatomic dications having formal single (He22+), double (NF2+) or triple (022+) bonds all seem to be well described as ordinary chemical bonds plus electrostatic repulsion<8 10). 

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