Vy. Kukushkin et al., Iminoacylation. 1. Addition of ketoximes or aldoximes to platinum(IV)-bound organonitriles, INORG CHEM, 37(25), 1998, pp. 6511-6517
The metal-mediated iminoacylation reaction of ketoximes or aldoximes upon t
reatment with the organonitrile platinum(IV) complexes trans-[PtCl4(RCN)(2)
] proceeds under relatively mild conditions in acetonitrile (R = Me) or in
chloroform (R = CH2Ph, Ph) to give trans-[PtCl4(NH=C(R)ON=CR1R2)(2)] (R-1 =
R-2 = Me; R1R2 = C4H8, R1R2 = C5K10, R1R2 = (H)Ph, R1R2 = (H)C6H4(OH)-o; 1
-14) in 90-95% yield. All these-compounds were characterized by elemental a
nalyses (C, H, N, Cl, Pt), FAB mass spectrometry, and IR and H-1, C-13{H-1}
, and Pt-195 NMR spectroscopies. X-ray structure determinations of [PtC4(NH
=C(Me)ON=CMe2)(2)] (1) and [PtCl4{NH= C(Me)ON=C(C5H10)}(2)] (3) disclosed t
heir overall trans-configuration and the amidine one-end rather than N,N-bi
dentate coordination made of the N-donor ligands. The iminoacyl species are
in E-conformation which is held by a rather weak N-H ... N hydrogen bond b
etween the amidine =NH atom and the oxime nitrogen with the following obser
ved distances and angles for 1 and [3]: N(1)... N(2), and N(1)-H, N(1)H ...
N(2) are 2.605 [2.592], 0.74 [0.71], and 2.20 [2.25] Angstrom; N(1)-H ...
N(2) is 115 degrees [111 degrees]. No evidence of the Z-conformation in sol
ution was obtained by NMR spectroscopy. Compounds trans-[PtCl4(NH=C(R)ON=CR
1R2)(2)] are unexpectedly stable toward hydrolysis both in the solid state
and in solutions.