Crystal structures of three N-ar­yl-2,2,2-tri­bromo­acetamides

Three N-ar­yl-2,2,2-tri­bromo­acetamides, namely, 2,2,2-tri­bromo-N-(2-fluoro­phen­yl)­acetamide, C(8)H(5)Br(3)FNO, (I), 2,2,2-tri­bromo-N-[3-(tri­fluoro­methyl)­phen­yl]­acetamide, C(9)H(5)Br(3)F(3)NO, (II) and 2,2,2-tri­bromo-N-(4-fluoro­phen­yl)­acetamide, C(8)H(5)Br(3)FNO, (III) were synthesized and their crystal structures were analysed. In the crystal structure of (I), C—Br⋯π(ar­yl) inter­actions connect the mol­ecules into dimers, which in turn are connected via Br⋯Br contacts [3.6519 (12) Å], leading to the formation of a one-dimensional ladder-type architecture. The crystal structure of (II) features chains linked by N—H⋯O and C—H⋯O hydrogen bonds. Two such chains are inter­linked to form ribbons through Br⋯Br [3.6589 (1) Å] and Br⋯F [3.0290 (1) Å] inter­actions. C—Br⋯π(ar­yl) and C—F⋯π(ar­yl) inter­actions between the ribbons extend the supra­molecular architecture of (II) from one dimension to two. In (III), the mol­ecules are connected into R (2) (2)(8) dimers via pairs of C—H⋯F inter­actions and these dimers form ribbons through Br⋯Br [3.5253 (1) Å] contacts. The ribbons are further inter­linked into columns via C—Br⋯O=C contacts, forming a two-dimensional architecture.