Crystal structures of dextrorotatory and racemic sodium ammonium tartrate
Abstract
The crystal structures of the title salts, (+)-Na[NH4][O2CCH(OH)CH(OH)CO2]·4H2O,(+)-(1a), and (±)-Na[NH4][O2CCH(OH)CH(OH)CO2]·H2O, (±)-(1b), have been determined from single-crystal X-ray data and refined by least-squares methods to R factors of 0.0482 and 0.0452, respectively. The unit-cell dimensions of (+)-(1a) are a= 12.173 9(9), b= 14.412 9(9), c= 6.235 2(9)Å, and Z= 4, space group P21212, and of (±)-(1b)a= 15.244(1), b= 5.066 3(7), c= 10.218 6(8)Å, β= 93.60(1)°, and Z= 4, space group P21/a. Hydrogen bonding in the lattice is found to be more extensive for the (+)-(1a) than for the (±)-(1b) structure, except for the ammonium ion bonding.