Crystal structures and fungicidal activities of anti-2,4-bis(X-phenyl)pentane-2,4-diols

The 1,3-diol moiety is present in a number of natural products and has some biological activity. Four symmetric anti-2,4-bis(X-phenyl)pentane-2,4-diols (a, X = p-F; b, X = p-CF3; c, X = m-OMe; d, X = m-CF3) have been characterized by X-ray diffraction, and the results indicated that the dihedral angles between the every two benzene rings in the systems are 34.38(10)°, 39.46(13)°, 23.42(7)°(A), 30.42(7)°(B) and 44.74(9)°, respectively. All of the structures were stabilized by classical intra- and intermolecular hydrogen bonding and some other weak interactions. It was observed that the hydrogen bonding patterns were formed between each single-molecule in compounds a–d, whereas H-bonding dimers were formed in the crystal lattices of both the anti- and syn-2,4-bisphenylpentane-2,4-diols. The four symmetric diaryl 1,3-diols were evaluated alongside several other 1,3-diols as potential antifungal agents, and their in vitro antifungal activities were measured against several fungal species, including Gibberella zeae, Botrytis cinerea, Alternaria alternata and Sclerotonia sclerotiorum.

► Four symmetric anti-2,4-bis(X-phenyl)pentane-2,4-diols (X = p-F; p-CF3; m-OMe; m-CF3) were characterized by X-ray diffraction.
► The classical intra- and intermolecular OH…O hydrogen bonded aggregates in the four compounds were observed to form one-dimensional infinite ribbons and then van der Waals interactions and some other weak interactions between the adjacent ribbons result in 3D supramolecular structures.
► The FTIR spectra of these molecules were recorded and were analyzed.
► More symmetric diaryl 1,3-diols as well as the four compounds were evaluated for their in vitro antifungal activities against several fungal species, including Gibberella zeae, Botrytis cinerea, Alternaria alternata and Sclerotonia sclerotiorum. Structure-activity relationship was analyzed.