A series of substituted (2E)-3-(2-fluoro-4-phenoxy­phen­yl)-1-phenyl­prop-2-en-1-ones

In the mol­ecular structures of a series of substituted chalcones, namely (2E)-3-(2-fluoro-4-phenoxy­phen­yl)-1-phenyl­prop-2-en-1-one, C₂₁H₁₅FO₂, (I), (2E)-3-(2-fluoro-4-phenoxy­phen­yl)-1-(4-fluoro­phen­yl)prop-2-en-1-one, C₂₁H₁₄F₂O₂, (II), (2E)-1-(4-chloro­phen­yl)-3-(2-fluoro-4-phenoxy­phen­yl)prop-2-en-1-one, C₂₁H₁₄ClFO₂, (III), (2E)-3-(2-fluoro-4-phenoxy­phen­yl)-1-(4-methyl­phen­yl)prop-2-en-1-one, C₂₂H₁₇FO₂, (IV), and (2E)-3-(2-fluoro-4-phenoxy­phen­yl)-1-(4-methoxy­phen­yl)prop-2-en-1-one, C₂₂H₁₇FO₃, (V), the configuration of the keto group with respect to the olefinic double bond is s-cis. The mol­ecules pack utilizing weak C—H...O and C—H...π inter­molecular contacts. Identical packing motifs involving C—H...O inter­actions, forming both chains and dimers, along with C—H...π dimers and π–π aromatic inter­actions are observed in the fluoro, chloro and methyl derivatives.

Four substituted pyrazolines

In the title compounds 5-(3-fluoro-4-phenoxy­phenyl)-1,3-biphenyl-4,5-dihydro-1H-pyrazole, C₂₇H₂₁FN₂O, (I), 3-(4-chloro­phenyl)-5-(3-fluoro-4-phenoxy­phenyl)-1-phenyl-4,5-dihydro-1H-pyrazole, C₂₇H₂₀ClFN₂O, (II), 5-(3-fluoro-4-phen­oxy­phenyl)-3-(4-methyl­phenyl)-1-phenyl-4,5-dihydro-1H-pyrazole, C₂₈H₂₃FN₂O, (III), and 5-(3-fluoro-4-phenoxy­phenyl)-3-(4-methoxy­phenyl)-1-phenyl-4,5-dihydro-1H-pyrazole, C₂₈H₂₃FN₂O₂, (IV), the five-membered pyrazole ring exists in an envelope conformation. The crystal structure of (I) has three independent C—H...π inter­molecular inter­actions. In (II), an inter­molecular C—Cl...π contact is present, forming mol­ecular chains. Replacement of this chloro group in (II) by a methyl group yields an isomorphic crystal structure, (III).