60105-97-7Relevant academic research and scientific papers
Iminoacylation. 3. Formation of platinum(IV)-based metallaligands due to facile one-end addition of vic-dioximes to coordinated organonitriles1-3
Kukushkin, Vadim Yu.,Pakhomova, Tatyana B.,Bokach, Nadezhda A.,Wagner, Gabriele,Kuznetsov, Maxim L.,Galanski, Markus,Pombeiro, Armando J. L.
, p. 216 - 225 (2008/10/08)
The reaction of vic-dioximes with the organonitrile platinum(IV) complexes trans-[PtCl4(RCN)2] (R = Me, CH2- Ph, Ph, vic-dioxime = dimethylglyoxime; R = Me, vic-dioxime = cyclohexa-, cyclohepta-, and cyclooctanedione dioximes) proceeds rapidly under relatively mild conditions and affords products of one-end addition of the dioximes to the nitrile carbon, i.e. [PtCl4(NH = C(R)ON = {spacer} = NOH)2] (1-6) (R = Me, CH2Ph, Ph, spacer = C(Me)C-(Me) for dimethylglyoxime; R = Me, spacer = C{C4H8}C, C{C5H(10)}C, C{C6H(12)}C for the other dioximes), giving a novel type of metallaligand. All addition compounds were characterized by elemental analyses (C, H, N, Cl, Pt), FAB mass spectrometry, and IR and 1H, (13)C{1H}, and (195)Pt NMR spectroscopy. X-ray structure determination of the dimethylformamide bis-solvate [PtCl4(NH = C(Me)ON = C(Me)C(Me) = NOH)2]·2DMF (1a) disclosed its overall trans geometry with the dimethylglyoxime part in anti configuration and the amidine one-end (rather than N,N-bidentate) coordination mode of the N-donor ligands. When a mixture of cis- and trans-[PtCl4(MeCN)2] in MeCN was treated with dimethylglyoxime, the formation of, correspondingly, cis- and trans-[PtCl4(NH = C(Me)ON = C(Me)C(Me) = NOH)2] (1) was observed and cis-to-trans isomerization in DMSO-d6 solution was monitored by 1H, 2D [1H, 15)N] HMQC, and (195)Pt NMR spectroscopies. Although performed ab initio calculations give evidence that the trans geometry is the favorable one for the iminoacylated species [PtCl4- (ligand)2], the platinum(IV) complex [PtCl4(NH = C(Me)ON = C{C4H8}C = NOH)2] (4) was isolated exclusively in cis configuration with the two metallaligand 'arms' held together by intramolecular hydrogen bonding between the two peripheral OH groups, as it was proved by single-crystal X-ray diffractometry. The classic substitution products, e.g. [PtCl2(N,N-dioximato)2] (12-15), are formed in the addition reaction as only byproducts in minor yield; two of them, [PtCl2(C7H11N2O2)2] (14) and [PtCl2(C8H13N2O2)2] (15), were structurally characterized. Complexes (12-15) were also prepared by reaction of the vic-dioximes with [PtCl4L(Me2SO)] (L = Me2SO, MeCN), but monoximes (Me2C = NOH, {C4H8}C = NOH, {C5H(10)}C = NOH, PhC(H) = NOH, (OH)C6H4C(H) = NOH) react differently adding to [PtCl4(MeCN)(Me2SO)] to give the corresponding iminoacylated products [PtCl4- (NH = C(Me)ON = CRR')(Me2SO)] (7-11).
