Fluoro-Germanium (IV) Cations with Neutral Co-Ligands—Synthesis, Properties and Comparison with Neutral GeF4 Adducts

The reaction of [GeF4L2], L = dmso (Me2SO), dmf (Me2NCHO), py (pyridine), pyNO (pyridine-N-oxide), OPPh3, OPMe3, with Me3SiO3SCF3 (TMSOTf) and monodentate ligands, L, in a 1:1:1 molar ratio anhydrous CH2Cl2 formed the monocations [GeF3L3][OTf]. These rare trifluoro-germanium (IV) cations were characterised by microanalysis, IR, 1H, 19F{1H} and, where appropriate, 31P{1H} NMR spectroscopy. data show that CH3NO2 solution complexes exist as mixture mer fac isomers, isomer invariably having higher abundance. X-ray structure mer-[GeF3(OPPh3)3][OTf] is also reported. attempts to remove second fluoride using further equivalent TMSOTf mostly unsuccessful, although [GeF2(OAsPh3)4][OTf]2 [GeF3(OAsPh3)3][OTf] was obtained excess OAsPh3. [GeF4(MeCN)2] solution, followed addition 2,2?:6?,2”-terpyridine (terpy) mer-[GeF3(terpy)][OTf], whilst similar 1,4,7-trimethyl-1,4,7-triazacyclononane (Me3-tacn) MeCN produced fac-[GeF3(Me3-tacn)][OTf]. Dicationic bearing GeF22+ fragment isolated tetra-aza macrocycles, 1,4,7,10-tetramethyl-1,4,7,10-tetra-azacyclododecane (Me4-cyclen) 1,4,8,11-tetramethyl-1,4,8,11-tetra-azacyclotetradecane (Me4-cyclam), which reacted two equivalents cleanly form dicationic difluoride salts, cis-[GeF2(Me4-cyclen)][OTf]2 trans-[GeF2(Me4-cyclam)][OTf]2. spectroscopy shows there are four stereoisomers present for trans-[GeF2(Me4-cyclam)][OTf]2, whereas smaller ring-size Me4-cyclen accounts formation only cis-[GeF2(Me4-cyclen)][OTf], confirmed crystallographically. New spectroscopic reported [GeF4(L)2] (L dmso, pyNO). Density functional theory calculations used probe effect on bonding ligands sequentially removed from germanium centre OPMe3 complexes.