Näther C, Jess I. Synthesis and crystal structure of diiso-thio-cyanato-tetra-kis-(4-methyl-pyridine
N-oxide)cobalt(II) and diiso-thio-cyanato-tris-(4-methyl-pyridine
N-oxide)cobalt(II) showing two different metal coordination polyhedra.
Acta Crystallogr E Crystallogr Commun 2024;
80:174-179. [PMID:
38333115 PMCID:
PMC10848974 DOI:
10.1107/s2056989024000471]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 02/10/2024]
Abstract
The reaction of Co(NCS)2 with 4-methyl-pyridine N-oxide (C6H7NO) leads to the formation of two compounds, namely, tetra-kis-(4-methyl-pyridine N-oxide-κO)bis-(thio-cyanato-κN)cobalt(II), [Co(NCS)2(C6H7NO)4] (1), and tris-(4-methyl-pyridine N-oxide-κO)bis-(thio-cyanato-κN)cobalt(II), [Co(NCS)2(C6H7NO)3] (2). The asymmetric unit of 1 consists of one CoII cation located on a centre of inversion, as well as one thio-cyanate anion and two 4-methyl-pyridine N-oxide coligands in general positions. The CoII cations are octa-hedrally coordinated by two terminal N-bonding thio-cyanate anions in trans positions and four 4-methyl-pyridine N-oxide ligands. In the extended structure, these complexes are linked by C-H⋯O and C-H⋯S inter-actions. In compound 2, two crystallographically independent complexes are present, which occupy general positions. In each of these complexes, the CoII cations are coordinated in a trigonal-bipyramidal manner by two terminal N-bonding thio-cyanate anions in axial positions and by three 4-methyl-pyridine N-oxide ligands in equatorial positions. In the crystal, these complex mol-ecules are linked by C-H⋯S inter-actions. For compound 2, a nonmerohedral twin refinement was performed. Powder X-ray diffraction (PXRD) reveals that 2 was nearly obtained as a pure phase, which is not possible for compound 1. Differential thermoanalysis and thermogravimetry data (DTA-TG) show that compound 2 start to decompose at about 518 K.
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