title: Crystal structure of rac-(3aR*,9aS*)-4,4,4-tri-chloro-1,2,3,3a,4,9a-hexa-hydro-4λ(5),9λ(4)-cyclo-penta-[4,5][1,3]tellurazolo[3,2-a]pyridine.
abstract: The title compound, C10H12Cl3NTe, crystallizes with two crystallographically independent mol-ecules (A and B) in the asymmetric unit. In each case, the coordination around the Te atom is distorted square-pyramidal, with the equatorial plane composed of the three Cl atoms and the C atom of the pyridinium ring. The Te atom is displaced from the mean-square plane by 0.1926 (7) and 0.1981 (8) Å, in mol-ecules A and B, respectivly, away from the apical C atom. The bond lengths from the Te atom to the two Cl atoms arranged trans to each other [2.5009 (7)/2.5145 (7) and 2.5184 (7)/2.5220 (8) Å in mol-ecules A and B, respectivly] are substan-ti-ally shorter than the third Te-Cl distance [2.8786 (7) and 2.8763 (7) Å in mol-ecules A and B, respectivly]. The 1,3-tellurazole ring is almost planar (r.m.s. deviations of 0.042 and 0.045 Å in mol-ecules A and B, respectivly). The cyclopentane rings in both molecules A and B adopt envelope conformations with the carbon atom opposed to the (Te)C-C(N) bond as the flap. In the crystal, mol-ecules form centrosymmetric 2 + 2 associates via Te⋯Cl inter-actions [3.3993 (7) and 3.2030 (7) Å]. As a result of these secondary inter-actions, the Te atom attains a strongly distorted 5 + 1 octa-hedral environment. Further, the 2 + 2 associates are bound by weak C-H⋯Cl hydrogen bonds into a three-dimensional framework.
authors.affiliation: Department of Chemistry, Baku State University, 23 Z. Khalilov St, Baku, AZ-1148, Azerbaijan.
authors.forename: Rizvan K
authors.initials: RK
authors.lastname: Askerov
authors.affiliation: R. E. Alekseev Nizhny Novgorod State Technical University, 24 Minin St, Nizhny Novgorod 603950, Russian Federation.
authors.forename: Julia M
authors.initials: JM
authors.lastname: Lukiyanova
authors.affiliation: R. E. Alekseev Nizhny Novgorod State Technical University, 24 Minin St, Nizhny Novgorod 603950, Russian Federation.
authors.forename: Zhanna V
authors.initials: ZV
authors.lastname: Matsulevich
authors.affiliation: R. E. Alekseev Nizhny Novgorod State Technical University, 24 Minin St, Nizhny Novgorod 603950, Russian Federation.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Borisov
authors.affiliation: Inorganic Chemistry Department, Peoples' Friendship University of Russia, 6 Miklukho-Maklay St, Moscow 117198, Russian Federation ; A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, 28 Vavilov St, Moscow 119991, Russian Federation.
authors.forename: Victor N
authors.initials: VN
authors.lastname: Khrustalev
keywords: C—H⋯Cl hydrogen bonding; Te⋯Cl inter­actions; arenetellurium trihalide; crystal structure