Crystal structures of 2-Hydroxyimino-1-phenylethan-1-one and ethyl 3-Oxo-2-sodiooxyiminobutanoate

The crystal structures of the title compounds, PhCOCH=NOH (5) and Na⁺[MeCOC(=NO^-)CO₂Et], - 2H₂O (10), have been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to R 0.051, 0.062 (815, 1199 ‘observed’ reflections) respectively. Crystals of (5) are monoclinic, P2₁/n, a 14.177(6), b 5. 075(4), c 11. 049(6) Å, β 112. 89(3)°, Z 4. Crystals of (10) are tetragonal, I4_I/a, a 19.41(1), c 10.643(5)Å, Z 16. In (5), within the C=NOH group, C-N is 1.263(4) and N-O is 1.375(4) Å in (10) C-N is 1.318(6) and N-O is 1.321(5)Å. In (10), the (presumably) negative C=NO^- group does not coordinate the sodium ion; the latter is bridged by water molecules, occupying four close coordination positions [2.405(4)-2.552(4) Å] in an interesting bridged polymeric array while the remaining two coordination positions are occupied by two ligand C=O groups [2.363(4), 2.393(4) Å], the ligands also bridging sodium ions.