Crystal structures of the dioxane hemisolvates of N-(7-bromo­methyl-1,8-naphthyridin-2-yl)acetamide and bis­[N-(7-di­bromo­methyl-1,8-naphthyridin-2-yl)acetamide]

The syntheses and crystal structures of N-(7-bromo­methyl-1,8-naphthyridin-2-yl)acetamide dioxane hemisolvate, C(11)H(10)BrN(3)O·0.5C(4)H(8)O(2), (I), and bis­[N-(7-di­bromo­methyl-1,8-naphthyridin-2-yl)acetamide] dioxane hemisolvate, 2C(11)H(9)Br(2)N(3)O·0.5C(4)H(8)O(2), (II), are described. The mol­ecules adopt a conformation with the N—H hydrogen pointing towards the lone electron pair of the adjacent naphthyridine N atom. The crystals of (I) are stabilized by a three-dimensional supra­molecular network comprising N—H⋯N, C—H⋯N and C—H⋯O hydrogen bonds, as well as C—Br⋯π halogen bonds. The crystals of compound (II) are stabilized by a three-dimensional supra­molecular network comprising N—H⋯N, C—H⋯N and C—H⋯O hydrogen bonds, as well as C—H⋯π contacts and C—Br⋯π halogen bonds. The structure of the substituent attached in the 7-position of the naphthyridine skeleton has a fundamental influence on the pattern of inter­molecular noncovalent bonding. While the Br atom of (I) participates in weak C—Br⋯O(guest) and C—Br⋯π contacts, the Br atoms of compound (II) are involved in host–host inter­actions via C—Br⋯O=C, C—Br⋯N and C—Br⋯π bonding.