Darstellung und Schwingungsspektrum des ersten Fluoro‐Chloro‐Iridats(V), Cs[IrF₅CI]

Abstract

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.

Preparation and Spectroscopic Investigations of Mixed Octahedral Complexes and Clusters

“…Similar investigations, sometimes supported by crystal structure determinations, have been performed on many series of the fluorochloro metalates [MF n Cl 6 - n ] z - of Ta(V), Os(IV), Os(V), Ir(IV), Ir(V), , and Pt(IV), fluorobromoosmates(IV), , chlorobromometalates [MCl n Br 6 - n ] z - of Nb(V), Ta(V), Tc(IV), Ru(IV), Rh(III), Os(IV), , Ir(III), Ir(IV), and Pt(IV), ,− bromoiodometalates [MBr n I 6 - n ] 2- of Re(IV), and Os(IV) , and the unique chloroiodo series [OsCl n I 6 - n ] 2- . , …”

“…Furthermore, the observed frequencies are very dependent on the cation present. 99 Similar investigations, sometimes supported by crystal structure determinations, have been performed on many series of the fluorochloro metalates [MF n Cl 6-n ] zof Ta(V), 102 Os(IV), 56 Os(V), 57 Ir(IV), 58 Ir-(V), 59,60 and Pt(IV), 103 fluorobromoosmates(IV), 44,45 chlorobromometalates [MCl n Br 6-n ] zof Nb(V), 102 Ta-(V), 102 Tc(IV), 104 Ru(IV), 105 Rh(III), 106 Os(IV), 15,107 Ir-(III), 108 Ir(IV), 108 and Pt(IV), 62,[109][110][111] bromoiodometalates [MBr n I 6-n ] 2of Re(IV), 112 and Os(IV) 113,114 and the unique chloroiodo series [OsCl n I 6-n ] 2-. 107,115 Besides these mixed-hexahalogeno metalates, there are several series of molecular compounds of the heavier transition metals and actinides, [MF n Cl 6-n ] (M ) Mo, W, Re, U, and Th), [116][117][118][119][120] some of which are volatile and stable in the gas phase.…”

“…The postulated stereospecific formation of fac -K 2 [PtF 3 Cl 3 ] as the sole oxidation product of K 2 [PtCl 6 ] with BrF 3 has never been verified. , Depending on the reaction conditions, other mixed species [PtF n Cl 6 - n ] 2- have been detected; however, for n = 2, 3, 4, only the cis/fac isomers have been present . Corresponding fluorochloro complexes are known for Re(IV,V), Os(IV,V), and Ir(IV,V). − Octahedral complexes containing the heavier halides, Br or I, together with F are rare, but are known for Pt(IV) and Os(IV), ,, and most notably Re(IV), for which there are many examples of 3-fold mixed species …”

“…55 Corresponding fluorochloro complexes are known for Re(IV,V), Os(IV,V), and Ir(IV,V). [56][57][58][59][60] Octahedral complexes containing the heavier halides, Br or I, together with F are rare, but are known for Pt(IV) and Os(IV), 13,42,45 and most notably Re(IV), for which there are many examples of 3-fold mixed species. 61 At first glance, the oxidative addition to quadratic planar systems seems a promising route to octahedral species with trans configuration, but caution should prevail.…”

“…284,285 As already mentioned, NMR spectroscopy on solutions and on solids 340 is very efficient for the elucidation of mixtures of diamagnetic and, with restrictions, of weakly paramagnetic complexes. 341 Suitable nuclei are NMR active metals like 59 Co, 93 Nb, 103 Rh and 195 Pt and ligand atoms like 15 N, 77 Se, and 13 C. 342,343 However, incomplete or ambiguous results are obtained, if NMR spectroscopy on less sensitive nuclei like 103 Rh or 13 C is performed with insufficient number of scans or pulse repetition times.…”