Three closely related thienyl-substituted 1,4-ep­oxy­naphtho­[1,2-b]azepines: hydrogen-bonded assembly in one, two and three dimensions

(2R,4S)-2-(3-Methyl­thio­phen-2-yl)-2,3,4,5-tetra­hydro-1,4-ep­oxy­naphtho­[1,2-b]azepine, C₁₉H₁₇NOS, (I), crystallizes with a single enanti­omer in each crystal, whereas its geometrical isomer (2RS,4SR)-2-(5-methyl­thio­phen-2-yl)-2,3,4,5-tetra­hy­dro-1,4-ep­oxy-naphtho­[1,2-b]azepine, (II), and (2RS,4SR)-2-(5-bromo­thio­phen-2-yl)-2,3,4,5-tetra­hydro-1,4-ep­oxy­naphtho­[1,2-b]azepine, C₁₈H₁₄BrNOS, (III), both crystallize as racemic mixtures. A combination of one C-H...O hydrogen bond and two C-H...[pi](arene) hydrogen bonds links the mol­ecules of (I) into a three-dimensional framework; the mol­ecules of (II) are linked into a C(4)C(4)[R₂²(7)] chain of rings by a combination of C-H...N and C-H...O hydrogen bonds; and in (III), where Z' = 2, a combination of four C-H...[pi](arene) hydrogen bonds and two C-H...[pi](thien­yl) hydrogen bonds links the mol­ecules into complex sheets. Comparisons are made with the assembly patterns in some aryl-substituted 1,4-ep­oxy­naphtho[1,2-b]azepines.