Anti-electrostatic hydrogen-bonded tellurate dimers captured and stabilized by crystallization of a bis-iminoguanidinium salt. (1st September 2022)

• Record Type: Journal Article
• Authors: Einkauf, Jeffrey D.; Bryantsev, Vyacheslav S.; Custelcean, Radu
• Is Part Of: Polyhedron. Volume 223(2022)
• Publication Date: 2022-09-01
• Subjects: Guanidine -- Crystallization -- Oxyanions -- Tellurium -- Tellurate; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2022.115990
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Sodium tellurate has been crystallized with a bis-iminoguanidinium chloride salt to form a rarely observed Te2 O6 (OH)4 4– dimer. The anionic dimers are further linked in the crystal into one-dimensional chains via anti-electrostatic hydrogen bonds involving the axial hydroxyl groups, stabilized by guanidinium and water hydrogen bonding. Abstract: Anionic Te2 O6 (OH)4 4– dimers have been captured by crystallization of a hydrated salt of glyoxal-bis-iminoguanidinium (GBIG), and structurally characterized by single-crystal X-ray diffraction and vibrational spectroscopy. The crystal structure reveals anti-electrostatic hydrogen-bonded chains of Te2 O6 (OH)4 4– dimers, consisting of edge-sharing TeO6 octahedra, stabilized by hydrogen bonding from the GBIG cations and the water molecules included in the crystal. FTIR spectroscopy confirms the presence of TeO6 octahedra with characteristic Te–O stretching modes at 755 cm −1 and 689 cm −1, while the observed stretching mode at 3459 cm −1 confirms the presence of axially-bonded hydroxyl groups. Raman spectroscopy and DFT calculations confirm the presence of the Te2 O6 (OH)4 4– dimers in the crystalline phase and of the TeO(OH)5 – monomers in solution.