Crystal structure and Hirshfeld surface analysis of 4,5-di-bromo-6-methyl-2-phenyl-2,3,3a,4,5,6,7,7a-octa-hydro-3a,6-ep-oxy-1H-isoindol-1-one

Crystal structures and Hirshfeld surface analyses of N,N-di-methyl-acetamide-1-(dimethyl-λ4-aza-nyl-idene)ethan-1-ol tribromide (1/1), N,N-di-methyl-acetamide-1-(dimethyl-λ4-aza-nyl-idene)ethan-1-ol di-bromido-iodate (1/1) and N,N-di-methyl-acetamide-1-(dimethyl-λ4-aza-nyl-idene)ethan-1-ol di-chlorido-iodate (1/1)

In the title compounds, N,N-di-methyl-acetamide-1-(dimethyl-λ4-aza-nyl-idene)ethan-1-ol tribromide (1/1), C4H9NO·C4H10NO+·Br3 - or [(C4H9NO)·(C4H10NO)](Br3), (I), N,N-di-methyl-acetamide-1-(dimethyl-λ4-aza-nyl-idene)ethan-1-ol di-bromido-iodate (1/1), C4H9NO·C4H10NO+·Br2I- or [(C4H9NO)·(C4H10NO)](Br2I), (II), and N,N-di-methyl-acetamide-1-(dimethyl-λ4-aza-nyl-idene)ethan-1-ol di-chlorido-iodate (1/1), C4H9NO·C4H10NO+·Cl2I- or [(C4H9NO)·(C4H10NO)]·(Cl2I), (III), all the anions are almost linear in geometry and all the cations, except for the methyl H atoms, are essentially planar. In the crystal structure of (I), the cations are linked by pairs of C-H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif. These dimers also exhibit O-H⋯O hydrogen bonding. Dimerized cation pairs and anions are arranged in columns along the a axis. In the crystal of (II), the cations are linked by pairs of O-H⋯O and C-H⋯O hydrogen bonds, forming an R 4 4(14) ring motif. These groups of cations and the anions form individual columns along the a axis and jointly reside in planes roughly parallel to (011). In the crystal of (III), cations and anions also form columns parallel to the a axis, resulting in layers parallel to the (020) plane. Furthermore, the crystal structures of (I), (II) and (III) are consolidated by strong halogen (Br and/or I and/or Cl)⋯H and weak van der Waals inter-actions. In addition to the structural evaluation, a Hirshfeld surface analysis was carried out.

Structural, Hirshfeld surface and three-dimensional inter-action-energy studies of 1,3,5-triethyl 2-amino-3,5-di-cyano-4,6-bis-(4-fluoro-phen-yl)cyclo-hex-1-ene-1,3,5-tri-carboxyl-ate

In the title compound, C₂₉H₂₇F₂N₃O₆, which crystallizes in the monoclinic space group P2₁/c, the cyclo-hexenone ring is puckered and adopts an envelope conformation. The crystal structure features various inter-molecular inter-actions, such as N-H⋯O, C-H⋯N and C-H⋯O. These inter-actions were investigated using Hirshfeld surface analysis and the three-dimensional inter-action energies were calculated using the B3LYP/6-31 G(d,p) energy density model.

(3aS,4R,5R,6S,7aR)-4,5-Di-bromo-2-[4-(tri-fluoro-meth-yl)phen-yl]-2,3,3a,4,5,6,7,7a-octa-hydro-3a,6-ep-oxy-1H-isoindol-1-one: crystal structure and Hirshfeld surface analysis

The asymmetric unit of the title compound, C15H12Br2F3NO2, consists of two crystallographically independent mol-ecules. In both mol-ecules, the pyrrolidine and tetra-hydro-furan rings adopt an envelope conformation. In the crystal, mol-ecule pairs generate centrosymmetric rings with R 2 2(8) motifs linked by C-H⋯O hydrogen bonds. These pairs of mol-ecules form a tetra-meric supra-molecular motif, leading to mol-ecular layers parallel to the (100) plane by C-H⋯π and C-Br⋯π inter-actions. Inter-layer van der Waals and inter-halogen inter-actions stabilize mol-ecular packing. The F atoms of the CF3 groups of both mol-ecules are disordered over two sets of sites with refined site occupancies of 0.60 (3)/0.40 (3) and 0.640 (15)/0.360 (15). The most important contributions to the surface contacts of both mol-ecules are from H⋯H (23.8 and 22.4%), Br⋯H/H⋯Br (18.3 and 12.3%), O⋯H/H⋯O (14.3 and 9.7%) and F⋯H/H⋯F (10.4 and 19.1%) inter-actions, as concluded from a Hirshfeld surface analysis.