Secondary bonding. Part 6. Distorted octahedral geometry in seleninyl dichloride–dioxan(1/1) and iodylbenzene

Abstract

The crystal structures of the title compounds have been determined from diffractometer data by the heavy-atom method. Crystals of SeOCl₂·C₄H₈O₂(1) are orthorhombic, space group Pna2₁, with a= 8.884(2), b= 12.066(3), c= 8.410(3), Z= 4, and R= 0.052 for 640 observed reflections. Crystals of C₆H₅IO₂(2) are monoclinic, space group P2₁, with a= 12.904 1(23), b= 6.402 3(14), c= 4.011 5(7), β= 99.018(14)° at –100 °C, Z= 2, and R= 0.048 for 755 observed reflections. Compounds (1) and (2) have primary pyramidal co-ordination with, respectively, bond lengths Se–O 1.572(1), Se–Cl 2.235(5) and 2.202(7)Å, and I–C 2.014(2), I–O 2.021(9), and 1.924(8)Å. For (1), the three weaker interactions are Se ⋯ O 2.614(13), 2.724(15), and 2.902(11)Å, and for (2), I ⋯ O 2.578(8), 2.660(10), and 2.733(9)Å. The interactions in (2) are the stronger, and produce significant distortion of the primary geometry, with an O–I–O angle of 147.8(4)°. The packing of (1) involves infinite layers of seleninyl dichloride bridged by dioxan molecules and further cross-linked by Se–O ⋯ Se interactions. In (2) the molecules form layers linked by I–O ⋯ I interactions.