The oxidative addition of SnCl4 to [W(CO)4(NCMe)(PPh3)].: The X-ray crystal structure of [WH(CO)3(NCMe)(PPh3)2]-[SnCl5•MeOH]

The oxidative addition reaction of SnCl4 with [W(CO)(4)(NCMe)(PPh3)] in acetonitrile gives a mixture of seven-coordinate tungsten(II) compounds: [WCl(SnCl3)(CO)(3)(NCMe)(PPh3)] (1), [WCl2(CO)(3)(NCMe)(PPh3)] (2) [WCl(SnCl3)(CO)(2)(NCMe)(2)(PPh3)] (3), and [WCl2(CO)(2)(NCMe)(2)(PPh3)] (4) identified by IR and NMR (H-1, C-13{H-1}, and P-31{H-1}) studies. Treatment Of [W(CO)(4)(NCMe)(PPh3)] with 1 equiv. of SnCl4 in CH2Cl2 solution besides compounds 1 and 2 also gives ionic species such as [HPPh3](+) and [SnCl6](2-) and cationic tungsten(II) complexes. The crystal structure of one of these, [WH(CO)(3)(NCMe)(PPh3)(2)][SnCl5 (.) MeOH] (5), has been established by single-crystal X-ray diffraction. The IR, H-1, C-13{H-13} and P-31{H-1} spectra of 5 are also described and can be correlated with the crystallographically observed geometry. A notable feature of 5 is the presence of an agostic interaction of the hydride ligand with one of the carbonyl ligands. (C) 2002 Elsevier Science Ltd. All rights reserved.