The crystal structures of two chalcones: (2E)-1-(5-chlorothiophen-2-yl)-3-(2-methylphenyl)prop-2-en-1-one and (2E)-1-(anthracen-9-yl)-3-[4-(propan-2-yl)phenyl]prop-2-en-1-one

MG thanks the UGC for the award of a Rajeev Gandhi fellowship and HSY thanks the University of Mysore for research facilities. JPJ acknowledges the NSF–MRI program (grant No. 1039027) for funds to purchase the X-ray diffractometer.In the crystal of compound (I), C14H11ClOS, molecules are linked by C---H···O hydrogen bonds to form simple it C(5) chains. Compound (II), C26H22O, crystallizes with it Z' = 2 in space group it P-1; one of the molecules is fully ordered but the other is disordered over two sets of atomic sites having occupancies 0.644 (3) and 0.356 (3). The two disordered components differ from one another in the orientation of the isopropyl substituents, and both differ from the ordered molecules in the arrangement of the central propenone spacer unit, so that the crystal of (II) contains three distinct conformers. The ordered and disordered conformers each form a it C(8) chain built from a single type of C---H···O hydrogen bond but those formed by the disordered conformers differ from that formed by the ordered form.Publisher PDFPeer reviewe