Isolation and Structural Characterization of Eightfold Protonated Octacyanometalates [M(CNH) 8 ] 4+ (M = Mo IV , W IV ) from Superacids
Résumé
Octacyanometalates K 4 [Mo(CN) 8 ] and K 4 [W(CN) 8 ] are completely protonated in superacidic mixtures of anhy-drous hydrogen fluoride and antimony pentafluoride. The resulting hydrogen isocyanide complexes [Mo(CNH) 8 ] 4+ [SbF 6 ] À 4 and [W(CNH) 8 ] 4+ [SbF 6 ] À 4 are the first examples of eight-coordinate homoleptic metal complexes containing hydrogen isocyanide (CNH) ligands. The complexes were crystallographically characterized, revealing hydrogen-bonded networks with short N···H···F contacts. Low-temperature NMR measurements in HF confirmed rapid proton exchange even at À40 8C. Upon protonation, n(C N) increases of about 50 cm À1 which is in agreement with DFT calculations.
Domaines
ChimieOrigine | Publication financée par une institution |
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