Darstellung,Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalysen der mer‐Trihalogeno‐tris‐Pyridin‐Osmium(III)Komplexe mer‐[OsX3Py3], X = Cl,Br, I |
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Authors: | S. Kolf W. Preetz |
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Abstract: | Synthesis, Crystal Structures, Vibrational Spectra, and Normal Coordinate Analyses of the mer ‐Trihalogeno‐tris‐Pyridine‐Osmium(III) Complexes mer‐[OsX3Py3], X = Cl, Br, I By reaction of the hexahalogenoosmates(IV) with pyridine and iso‐amylalcohol mer‐trihalogeno‐tris‐pyridine‐osmium(III) complexes are formed and purified by chromatography. X‐ray structure determinations on single crystals have been performed of mer‐[OsBr3Py3] (monoclinic, space group P21/n, a = 9.098(5), b = 12.864(5), c = 15.632(5) Å, β = 90.216(5)°, Z = 4) and mer‐[OsI3Py3] (monoclinic, space group P21/n, a = 9.0952(17), b = 13.461(4), c = 15.891(10), β = 91.569(5)°, Z = 4). The pyridine rings are twisted propeller‐like against the N3 meridional plane with mean angles of 49° (Cl), 46° (Br), 44° (I). Based on the molecular parameters of the X‐ray structure determinations and assuming C2 point symmetry, the IR and Raman spectra are assigned by normal coordinate analysis. Due to the stronger trans influence of pyridine as compared with the halide ligands for N'–Os–X · axes significantly different valence force constants are observed in comparison with symmetrically coordinated octahedron axes: fd(OsCl) = 1.74, fd(OsCl·) = 1.49, fd(OsBr) = 1.43, fd(OsBr · ) = 1.18, fd(OsI) = 0.99, fd(OsI · ) = 0.96, fd(OsN) between 1.96 and 2.07 and fd(OsN') between 2.13 and 2.32 mdyn/Å. |
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Keywords: | mer‐Trichloro‐tris‐pyridine‐osmium(III) mer‐Tribromo‐tris‐pyridine‐osmium(III) mer‐Triiodo‐tris‐pyridine‐osmium(III) Crystal Structure IR Spectra Raman Normal Coordinate Analysis |
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