The synthesis, characterization, and structure of (ThioH)2[OsX6] (X = Cl, Br)

Novel osmium complexes (ThioH)2[OsCl6] (1) and (ThioH)2[OsBr6] (2) have been synthesized via the interaction of H2[OsX6] (X = Cl, Br) with thiourea (Thio) in concentrated HX and characterized by chemical analysis, potentiometry, IR- and UV–Vis spectroscopy, X-ray powder and single-crystal diffraction. UV–Vis spectroscopy of 1 and 2 in solutions supports the preservation of [OsX6]2− ions that however demonstrate considerable solvatochromism. The longer-wavelength bands experience a hypsochromic shift with respect to the crystalline state. Intense bands of Os-halogen vibrations in ATR IR spectra are red-shifted with respect to those for K2[OsX6]. The complexes are isostructural and crystallized in the triclinic space group P1¯, Z = 1. Unit cell parameters are for 1: a = 7.1800(14) Å, b = 7.2700(15) Å, c = 7.7800(16) Å, α = 78.89(3)°, β = 87.83(3)°, γ = 65.11(3)°; for 2: a = 7.3169(15) Å, b = 7.5504(15) Å, c = 8.2065(16) Å, α = 80.00(3)°, β = 88.55(3)°, γ = 63.37(3)°. The cations (NH2)2CSH+ and anions [OsX6]2− are assembled into two-tier layers by N–H…X and S–H…X hydrogen-bonds and S…X non-valent contacts. © 2017 Elsevier Ltd