Synthesis, Spectroscopic and Structural Systematics of Complexes of Germanium(IV) Halides (GeX₄, X = F, Cl, Br or I) with Phosphane Oxides and Related Oxygen Donor Ligands

Abstract

The first series of phosphane oxide complexes of germanium(IV) halides have been prepared, including trans‐[GeF4(R3PO)2] (R = Me, Et or Ph), trans‐[GeCl4(Et3PO)2], fac‐[GeCl3(Me3PO)3]2[GeCl6] and cis‐[GeX2(Me3PO)4]X2 (X = Cl or Br) and characterised by IR and multinuclear NMR (1H, 19F{1H} and 31P{1H}) spectroscopy. Crystal structures of all the above (except trans‐[GeCl4(Et3PO)2]) are described. Remarkably, under mild conditions Me3PO displaces halide ligands from GeX4 (X = Cl, Br) to form the cationic species above. Ph3AsO forms trans‐[GeF4(Ph3AsO)2], but reaction of Ph3AsO or Me3AsO with GeCl4 leads to the corresponding R3AsCl2. The complexes [GeF4(MeCN)2], [GeF4(thf)2] and [GeF4(MeOCH2CH2OMe)] are also described and the relative Lewis acidities of GeX4 established. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Synthesis, Spectroscopic and Structural Systematics of Complexes of Germanium(IV) Halides (GeX4, X = F, Cl, Br or I) with Mono‐, Bi‐ and Tri‐Dentate and Macrocyclic Nitrogen Donor Ligands

“…GeF 4 is a gas (sub. 236 K) and inconvenient to handle in this form, and the nitrile adduct, [GeF 4 (MeCN) 2 ] [14] is a more convenient precursor. The reaction of [GeF 4 2 ] where varying amounts of cis and trans isomers were found in solution in chlorocarbons.…”

“…The reaction of [GeF 4 2 ] where varying amounts of cis and trans isomers were found in solution in chlorocarbons. [14] The structure of [GeF 4 (2,2Ј-bipy)] [9] is the only literature structure of a GeF 4 …”

“…[6] A few more examples have been reported in the intervening years, [7][8][9][10][11][12][13] but data on series of complexes, solution speciation studies or even establishment of the boundaries of complex formation are elusive. We have begun a detailed examination of the coordination chemistry of germanium(IV), and have recently reported a series of phosphane oxide adducts of the tetrahalides, [14] including trans-[GeF 4 4 ]X 2 (X = Cl or Br). The ability of R 3 PO to displace Cl or Br from the GeX 4 to form the cationic complexes was unexpected and is unknown in the corresponding tin(IV) systems.…”

“…(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) to the corresponding R 3 AsCl 2 , again contrasting with the tin(IV) systems. [14] This present study focuses on nitrogen donor ligands of a variety of architectures and denticities, especially the complexes with GeF 4 . A more limited range of examples with GeCl 4 and GeBr 4 were examined for comparison purposes.…”

Study on the Equilibria of the Complex Formation of the Ion-pair of Germanium(IV) with 4-Nitrocatechol and 1,4-Diphenyl-3-(phenylamino)-1H-1,2,4-triazole

“…The complexes of germanium with chelate ligands containing O, N and S donor atoms have diverse industrial, biological, pharmacological and medical applications. [9][10][11][12][13][14][15][16][17] Germanium(IV) gives colored chelates with aromatic compounds, containing two or more hydroxyl groups in o-position relative to each other. The colored anionic chelates of Ge(IV) form ion-associated complexes with bulky organic cations, like tetradecyl(trihexyl)phosphonium, methyltrioctylammonium, tetrazolium, cetylpyridinium, cetyltrimethylammonium, tetraphenylammonium, tetraphenylarsonium.…”