ChemInform Abstract The reaction of (PtCl6)2-with BrF3 yields the mixed complexes (PtFnCl6-n)2-with n = 1-5; the product distribution depends on the reaction temp. and time. The complexes with n = 2, 3, 4 have cis-configuration. Due to the stronger trans-effect of Cl compared to F, trans-isomers can be generated stereospecifically by treatment of (PtF5Cl)2-and cis-(PtF4Cl2)2-with Cl-. The vibrational spectra of the mixed complexes are completely assigned according to the point groups D4h (trans-isomers with n = 2, 4), C4v (n = 1, 5), C3v (cis-isomer, n = 3), and C2v (cis-isomers, n = 2, 4; and trans-isomer, n = 3).

AbstractThe stepwise replacement of ligands in [OsCl6]2- by oxidation with BrF3 generates the mixed complexes [OsFnCl6-n]2-, n = 1 - 5, of which the species with n = 2,3,4 are cw-configurated. Due to the stronger trans-effect of Cl compared to F on treatment of [OsF5Cl]2- and cis-[OsF4Cl2]2- with Cl- the trans-isomers are formed stereospecifically. The pure fluoro-chloro-osmates(IV) are separated by ion exchange chromatography on diethylaminoethylcellulose. From the pairs of stereoisomers the cis-compounds are always first eluted, whereas the trans-complexes are moving faster in an electric field by 3 to 5% . The vibrational spectra of octahedral mixed ligand complexes are generally discussed according to point groups Oh, D4h, C4v, C3v and C2v. For the fluoro-chloroosmates(IV) all stretching and deformation bands are assigned. They are observed in the characteristic regions; ν(OsF): 625-490 > ν(OsCl): 360-300 > δ (FOsF): 275-210 > δ (FOsCl) > δ (ClOsCl): 190-150 > νL: < 100 cm -1.

Bei der Umsetzung von [IrCl6]2− mit BrF3 in flüssigem HF entsteht das Komplexgemisch [IrFnCl6−n]−, n = 1–6, aus dem als erste Cl‐haltige Verbindung des fünfwertigen Iridiums des dunkelrote Cs[IrF5Cl] in reiner Form isoliert wurde. Das IR‐ und Ramanspektrum ließ sich vollständig entsprechend der Punktgruppe C4v zuordnen. Die im Vergleich zum entsprechenden IrIV‐Komplex größere Bindungsfestigkeit zeigt sich in einer beträchtlichen Verschiebung der Schwingungen zu höheren Wellenzahlen und der Zunahme der Valenzkraftkonstanten um etwa 20% an.

The reaction of [IrCl6]2- with BrF3 generates the mixed complexes [IrFnCl6-n]2-, n = 1-5, of which the species with n = 2, 3, 4 are ds-configurated. Due to the stronger trans-effect of Cl as compared to F on treatment of [IrF5Cl]2- and cis-[IrF4Cl2]2- with SOCl2 the trans-isomers are formed stereospecifically. The pure fluoro-chloro-iridates(IV) are separated by ion exchange chromatography on diethylaminoethyl-cellulose. The vibrational spectra of the mixed ligand complexes are completely assigned according to point groups D4h, C4v, C3v, and C2v. The IrCl stretching vibration of [IrF5Cl]2- is split by the isotopes 35C1 and 37Cl, showing two well resolved sharp Raman lines at 361 and 355 cm-1.

The mixed chloro-bromo complexes [PtClnBr6-n]2-, n = 1-5, are separated by ion exchange chromatography on diethylaminoethylcellulose. The separation of corresponding stereoisomers for n = 2, 3, 4 is not possible. Due to the stronger trans-effect of Br compared with Cl, on treatment of [PtBrß]2- with Cl- in the presence of Br2 nearly pure cis-isomers, and by reaction of [PtClsBr]2- and cis-fPtC^Bro]2- with Br~/Br2 completely pure transisomers are formed. The stereoselectivity of the successive ligand exchange reactions is better than in corresponding series of Re, Os and Ir. The highly resolved vibrational spectra allow the distinction of the mixed ligand complexes as well as the estimation of purity of the isomers. All allowed stretching frequencies are observed and assigned according to point groups D4h, C4V, C3V and C2V. Especially in the ν(Pt-Br) region it is possible to distinguish bands arising either from symmetric Br-Pt-Br or asymmetric Cl-Pt-Br axes. The UV/VIS spectra exhibit systematic hypsochromic shifts on the successive exchange of Br-ligands by Cl. A critical discussion of the literature concerning chloro-bromo-platinates- (IV) shows the importance of effective separation processes for the isolation of pure mixed ligand complexes