Crystal analyses by A. Chandrasekaran for Lora M. Field.

This molecule made by Lora M. Field as a stable radical that would have extended hydrogen-bonding and possibilities for coordination with paramagnetic ions (as the dicarboxylate anion).  There are two crystalline phases discovered so far.

The a-phase has two crystallographically distinct molecules alternating in a hydrogen-bonded chain formed by typical carboxylic acid dimer bonding.  The space group is triclinic with P-1 symmetry. Herringbone interactions between the phenyl ring of a phenyl-nitroxide in one hydrogen-bonded chain link and the phenyl ring in another chain causes this structure to give interdigitated hydrogen-bonded chains.  The phenyl-nitroxide units are thus brought into reasonably close proximity by a combination of carboxylic acid hydrogen bonding, and herringbone interactions.

The b-phase is quite similar to the a-phase, but in an orthorhombic space group. Aside from this difference (resulting in one molecule per unit cell), the qualitative features of the crystallographic packing are the same as described in the previous paragraph.

Tested on a Windows-based Pentium PC using Netscape version 4.7 with the Chime 2.6 (service pack 4) plugin installed.

Tested on a Windows-based Pentium PC using Internet Explorer version 6 with the Chime 2.6 (service pack 4) plugin installed.