Crystal structure and Hirshfeld analysis of 3′-bromo-4-methyl­chalcone and 3′-cyano-4-methyl­chalcone

Two crystal structures of chalcones, or 1,3-di­aryl­prop-2-en-1-ones, are presented; both contain a methyl substitution on the 3-Ring, but differ on the 1-Ring, bromo versus cyano. The compounds are 3′-bromo-4-methyl­chalcone [systematic name: 1-(2-bromo­phen­yl)-3-(4-methyl­phen­yl)prop-2-en-1-one], C 16 H 13 BrO, and 3′-cyano-4-methyl­chalcone {systematic name: 2-[3-(4-methyl­phen­yl)prop-2-eno­yl]benzo­nitrile}, C 17 H 13 NO. Both chalcones meaningfully add to the large dataset of chalcone structures. The crystal structure of 3′-cyano-4-methyl­chalcone exhibits close contacts with the cyano nitro­gen that do not appear in previously reported disubstituted cyano­chalcones, namely inter­actions between the cyano nitro­gen atom and a ring hydrogen atom as well as a methyl hydrogen atom. The structure of 3′-bromo-4-methyl­chalcone exhibits a type I halogen bond, similar to that found in a previously reported structure for 4-bromo-3′-methyl­chalcone.