Synthesis and characterization of tin tetrafluoride adducts with fluoroalkyl phosphoryl ligands

The reaction of SnF4 with (R2N)nP(O)(OCH2CF3)3−n (n = 0–2) produces a series of new octahedral complexes of SnF4L2 type (L = (R2N)2P(O)OCH2CF3; R = Me (1); Et (2), L = R2NP(O)(OCH2CF3)2; R = Me (3); Et (4) or L = P(O)(OCH2CF3)3 (5)). The adducts have been characterized by multinuclear (19F, 31P and 119Sn) NMR, IR spectroscopy and elemental analyses. The NMR data particularly the 19F NMR spectra show the existence of complexes as mixtures of cis and trans isomers. The variable temperature NMR study in CH2Cl2 solutions in the presence of excess ligand indicated that the ligand exchange at room temperature is slow for 1–4 and fast only for 5. The results were compared with those of SnCl4 analogues and show the formation of higher trans ratios for the studied complexes.