Enantiomeric O-methylphenylphosphinylacetic acid

C9H1104P , M, = 214.16, tetragonal, space group P4~2~2, Z = 8, a = 8.19 (1), c = 31.19 (4) A, V = 2092.1 A a, D,, = 1.37, D x = 1.363 g cm-a,F(000) = 896, /t(Cu Ka) = 22-6 cm -~. The structure was solved by direct methods (MULTAN) and refined by full-matrix least-squares calculations with anisotropic thermal parameters to a final R value of 0.074 for 1416 independent intensities collected on a Weissenberg camera. Strong hydrogen bonds (2.57/k) connect the molecules in chains.