In a new collaboration with the group of Jon Steed in Durham, the significant insight obtained from the judicious use of electronic structure theory is evident. Here, relatively simple DFT calculations were used to demonstrate that the chemical picture of water as bonding through sp3 hybridised ‘rabbit ear’ lone pairs is an incomplete model; the directionality of the lone pairs is such that bonding can occur in what might be considered an sp2 motif. This discrepancy arises due to the approximate nature of the hybridisation model. Theory was therefore able to explain the bonding observed in an unusual coodination motif observed in a new crystal structure.

In For the abstract, and access to the full text, see below.

The disodium salt of diatrizoic acid crystallises as a tetragonal channel hydrate structure. One of the incorporated water molecules is coordinated to three individual sodium cations in a unique geometry.