2-Hydroxy-7-nitrocyclohepta-2,4,6-trien-1-one

Abstract

The title compound, also known as 7-nitro­tropolone, C7H5NO4, exists in the crystalline state as the 2-hy­droxy-7-nitro­cyclo­hepta-2,4,6-trien-1-one tautomer and not as 2-hy­droxy-3-nitro­cyclo­hepta-2,4,6-trien-1-one. The dihedral angle between the ring and the nitro group is 70.3 (2)°. In the crystal, neighbouring mol­ecules are linked into dimers by a pair of O—H⋯O hydrogen bonds. In addition, the crystal is stabilized by O⋯π [3.4039 (14) Å] and O⋯O [3.073 (2) Å] inter­actions.

Crystal structure of 3,5,7-tris(morpholinomethyl)tropolone·0.67 hydrate, C22H33N3O5·0.67H2O

“…The C1-C2 bond distance of the structure reported here and the structure of tropolone are determined as 1.496(2) Å and 1.4542(5) Å respectively and also compare well. All the bond distances and angles are in agreement to similar structures in literature [12,13]. 3,5,7-tris(morpholinomethyl)tropolone was coordinated to the rhodium(I) showing bond angles and bond distances in the metal complex similar to the uncoordinated molecule [14].…”

Design of Cocrystals for Molecules with Limited Hydrogen Bonding Functionalities: Propyphenazone as a Model System

“…A number of multicomponent systems [36][37][38][39][40][41][42][43] have been reported for antipyrine and edaravone, from which additional knowledge can be gained and can be used in the design and search for cocrystals of PROPY. An analysis of these systems indicate that most of the coformers feature CO2H donor groups.…”

Crystal engineering of a co-crystal of antipyrine and 2-chlorobenzoic acid: relative energetic contributions based on multipolar refinement

“…This drug, when consumed, acts on the central nervous system (CNS) leading to the non-selective inhibition of both isoforms of cyclooxygenase (COX-1, COX-2) enzymes which are involved in prostaglandin (PG) synthesis. 23,25,26 To date, several literature reviews focusing on antipyrine (API) cocrystals with suitable co-formers namely salicylic acid, 27 saccharin, fumaric acid, 28 4-aminobenzoic acid, 29 sulphanilamide, 30 4,4′-propane-2,2′-diyldiantipyrine 31 and sulfaguanidine 32,33 have been published. In addition, the literature also contains cocrystals of phenazone derivatives like propyphenazone-pyrithyldione, 34 propyphenazonehydroquinone, 35 4-aminoantipyrine-fumaric acid, 28 4-aminoantipyrine-2-amino benzoic acid, 36 etc.…”