Chemists play with symmetries.
Identical-radius spheres densely pack. An octahedrally coordinated metal ion is mostly spherical. Symmetric bidentate chelate ligands give chiral point group
C3 three-bladed propeller molecules, with a
/_\-(delta) right hand screw or a
/\-(lambda) left hand screw. Do identical radius homochiral cations and anions give a chiral cubic lattice with only rotational symmetries?
Inorg. Syn. 6 186 (1960)
{Co(en)3}(3+)
en = 1,2-diaminoethane
Inorg. Syn. 8 204 (1966)
{Co(ox)3}(3-)
ox = oxalate dianion
Both complex ions occur as fully resolved optical isomers. Will the homochiral 1:1 salt be FCC/CCP close packed? Will the unit cell have its axes tilted out of cubic? Will the macroscopic crystal have interesting optical properties?
http://www.mazepath.com/uncleal/trisco.png Trivalent ions of identical size build a strongly bonded lattice. It would make an interesting science project.
