Download citation
Download citation
link to html
The monoclinic crystals (space group P21/a, Z = 8) of 2-phenyl-4-hydroxyphthalazin-1-one, C14H10N2O2, have two independent molecules (A and B) in the asymmetric unit. Both occur as the lactim–lactam (hydroxy–one) structure, which is also found in the parent molecule maleic hydrazide (both triclinic and monoclinic polymorphs), dichloromaleic hydrazide and luminol (3-aminophthalhydrazide). The molecular arrangement is based on strings of alternating A and B molecules linked by hydroxyl...carbonyl hydrogen bonds, with only van der Waals interactions between adjacent strings. Comparison is made of the measured bond lengths for (monoclinic) maleic hydrazide and values from high-level ab initio calculations, and reasonably good agreement is obtained, with indications of improvements when allowance is made for electron correlation and hydrogen bonding.

Supporting information

cif

Crystallographic Information File (CIF)
Contains datablock nogaBJuly97

hkl

Structure factor file (CIF format)
Contains datablock nogaBJuly97

CCDC reference: 131737

-1
Follow Acta Cryst. B
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds