title: (3-Chloro-phen-yl){2-eth-oxy-5-[(Z)-hydroxy(phen-yl)methyl-idene]cyclo-penta-1,3-dien-1-yl}methanone.
abstract: The title compound, C(21)H(17)ClO(3), which crystallizes as one of two possible oxo/hy-droxy-fulvene prototropic tautomers, possesses a strong intra-molecular O-H⋯O hydrogen bond that closes a seven-membered ring. The dihedral angles between the central five-membered ring and two pendant rings are 55.05 (9) and 44.51 (10)°. The crystal packing is characterized by weak inter-molecular C-H⋯O inter-actions between an H atom of the oxymethyl-ene unit and the carbonyl group of an adjacent mol-ecule, resulting in formation of chains of mol-ecules along the a axis.
authors.forename: Mihaela-Liliana
authors.initials: ML
authors.lastname: Tinţaş
authors.forename: Richard A
authors.initials: RA
authors.lastname: Varga
authors.forename: Ion
authors.initials: I
authors.lastname: Grosu
authors.forename: Elena
authors.initials: E
authors.lastname: Bogdan