Kristallstrukturen, Schwingungsspektren und Normalkoordinatenanalyse vonfac-(Et4N)[OsF3Cl3] undfac-(Et4N)[IrF3Cl3]

Abstract

Bei der vorsichtigen Oxidation der reinen Fluorochloroosmate(IV) oder ‐iridate(IV) mit BrF3 oder KBrF4 in Dichlormethan entstehen die gemischten fünfwertigen Komplexanionen fac‐[OsF3Cl3]– und fac‐[IrF3Cl3]–. Röntgenstrukturanalysen sind an Einkristallen von fac‐(Et4N)[OsF3Cl3] (1) (orthorhombisch, Raumgruppe Pbca, a = 11,225(5), b = 12,020(5), c = 21,837(5) Å, Z = 8) und fac‐(Et4N)[IrF3Cl3] (2) (orthorhombisch, Raumgruppe Pbca, a = 11,269(10), b = 12,049(1), c = 21,801(3) Å, Z = 8) durchgeführt worden. Unter Verwendung der röntgenographisch ermittelten Molekülparameter werden die registrierten IR‐ und Raman‐Spektren für das Anion von 1 und 2 durch Normalkoordinatenanalysen zugeordnet. Die Osmium‐Verbindung zeigt etwas größere Valenzkraftkonstanten als die Iridium‐Verbindung: fd(OsF) = 3,35, fd(IrF) = 3,25, fd(OsCl) = 2,35 und fd(IrCl) = 2,25 mdyn/Å.

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“…0.1 of an electron is transferred from the phosphorus atom to bromine on complex formation. 21 The use of interhalogens as oxidative fluorinating agents is well documented; BrF 3 and KBrF 4 have been used to synthesise complexes containing the chlorofluoro-osmate(V) 22 and -iridate(V) 23 cations. Meanwhile, excellent yields of aromatic iodides are reported for aromatic iodination reactions using ICl in the presence of catalytic amounts of ferrocenium tetrakis(3,5-bis(trifluoromethyl)phenyl)borate.…”

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“…90 A similar reaction was found for the one-electron oxidation of fac-[OsCl 3 F 3 ] 22 , for which KBrF 4 could also be used. 91 However PbO 2 /CF 3 CO 2 H was used for this reaction with trans-[OsCl 2 F 4 ] 22 . 92 [OsCl 5 (H 2 O)] 2 is claimed to be the first Os(IV) chloroaqua complex, and was made by reducing OsO 4 by sulfite in the presence of chloride.…”

“…Careful oxidation of fac-[IrCl 3 F 3 ] 22 with BrF 3 or KBrF 4 gave the monoanion, characterised by IR and Raman spectra and X-ray crystallography. 140 The reaction of [IrBr 6 ] 22 with KNCS gave linkage isomers of trans-[IrBr 2 (NCS) n (SCN) 4 2 n ] 22 (n = 0-2) with IR and Raman spectra and a crystal structure determination for n = 0. 141 GeBr 2 in HBr forms [GeBr 3 ] 2 , which forms complexes with IrBr 3 , giving [IrBr n (GeBr 3 ) 6 2 n ] 32 , which were isolated for n = 3-5 as Cs + salts, that with n = 4 proving more labile to substitution than [IrBr(SnBr 3 ) 5 ] 32 .…”