Two isostructural 3-(5-ar-yloxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(thio-phen-2-yl)prop-2-en-1-ones: disorder and supra-molecular assembly.

Two new chalcones containing both pyrazole and thio-phene substituents have been prepared and structurally characterized. 3-(3-Methyl-5-phen-oxy-1-phenyl-1H-pyrazol-4-yl)-1-(thio-phen-2-yl)prop-2-en-1-one, C23H18N2O2S (I), and 3-[3-methyl-5-(2-methyl-phen-oxy)-1-phenyl-1H-pyrazol-4-yl]-1-(thio-phen-2-yl)prop-2-en-1-one, C24H20N2O2S (II), are isomorphous as well as isostructural, and in each the thio-phene substituent is disordered over two sets of atomic sites having occupancies 0.844 (3) and 0.156 (3) in (I), and 0.883 (2) and 0.117 (2) in (II). In each structure, the mol-ecules are linked into sheets by a combination of C-H⋯N and C-H⋯O hydrogen bonds. Comparisons are made with some related compounds.