NEUTRON REFINEMENT OF THE CRYSTAL-STRUCTURE OF PARTIALLY EXCHANGED TAURINE, (ND3-()(0.65)(NH3+)(0.35)(CH2)(2)SO3)

Refinement of neutron-diffraction data from a partially deuteriated si ngle crystal of taurine, 2-aminoethylsulfonic acid, confirms the zwitt erion structure, ND3+(CH2)(2)SO3-, at room temperature; the S-C-C-N to rsion angle of the gauche configuration in the solid state is -69.4 de grees. Hydrogen positions have been located more precisely than in the earlier X-ray analysis to yield apparent bond lengths N-D/H = 1.02(1) Angstrom and C-H = 1.08(1) Angstrom.