2,3-Dihydro-1H-cyclo­penta­[b]naph­tha­len-1-ol

In the title compound, C₁₃H₁₂O, the cyclo­pentene ring fused with the naphthalene group adopts an envelope conformation. The cyclo­pentene torsion angle, with the fusion bond at the centre, has a magnitude of 1.16 (16)°. In the crystal, neigh­bouring mol­ecules are connected through O—H...O hydrogen bonds into an R₄⁴(8) ring motif. The crystal packing also features weak π–π stacking inter­actions [centroid–centroid distance = 3.8981 (8) Å] and C—H...π inter­actions.

5-Amino-4-bromo-2,3-dihydro-1H-inden-1-one

In the title compound, C₉H₈BrNO, the non-H-atom framework is essentially planar, with a maximum deviation of 0.087 (3) Å. In the crystal, mol­ecules are inter­connected into a three-dimensional network by C—H...O and N—H...O hydrogen bonds. In addition, C—H...π inter­actions and a π–π stacking inter­action, with a centroid–centroid distance of 3.5535 (19) Å, are also observed.

2,4-Dibromo-2,3-dihydro-1H-inden-1-yl acetate

In the title compound, C₁₁H₁₀Br₂O₂, the cyclo­pentene ring fused to the benzene ring adopts an envelope conformation, with the C atom attached to the Br atom as the flap. The crystal structure does not exhibit any classical hydrogen bonds. The mol­ecular packing is stabilized by van der Waals forces and π–π stacking inter­actions with a centroid–centroid distance of 3.811 (4) Å.

2,5-Dibromo­indan-1-ol

In the title compound, C₉H₈Br₂O, the cyclo­pentene ring adopts an envelope conformation with the brominated C atom as the flap. In the crystal, mol­ecules are linked by strong O—H...O hydrogen bonds into zigzag C(4) chains along [010]. In addition, a C—H...π inter­action involving the benzene ring and the H atom attached to the hy­droxy­lated C atom is observed.