Kukushkin V Y, Pakhomova T B, Bokach N A, Wagner G, Kuznetsov M L, Galanski Mathea Sophia, Pombeiro A J
Department of Chemistry, St Petersburg State University, Russian Federation.
Inorg Chem. 2000 Jan 24;39(2):216-25. doi: 10.1021/ic990552m.
The reaction of vic-dioximes with the organonitrile platinum(IV) complexes trans-[PtCl4(RCN)2] (R = Me, CH2Ph, 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. [PtC4(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[C5H10]C, C[C6H12]C for the other dioximes), giving a novel type of metallaligand. All addition compounds were characterized by elemental analyses (C, H, N, C1, Pt), FAB mass spectrometry, and IR and 1H, 13C[1H], and 195Pt NMR spectroscopy. X-ray structure determination of the dimethylformamide bis-solvate [PtCl4(NH=C(Me)ON=C(Me)C(Me)=NOH)2] x 2DMF (la) 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-[PtC4(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,15N] HMQC, and 195Pt 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[C4Hs]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. [PtC12(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, [C5H10]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).
在相对温和的条件下，偕二肟与有机腈铂（IV）配合物反式-[PtCl₄(RCN)₂]（R = 甲基、苄基、苯基，偕二肟 = 丁二酮肟；R = 甲基，偕二肟 = 环己二酮二肟、环庚二酮二肟和环辛二酮二肟）迅速反应，生成二肟在腈基碳上进行单端加成的产物，即[PtC₄(NH=C(R)ON=[间隔基]=NOH)₂]（1 - 6）（R = 甲基、苄基、苯基，对于丁二酮肟，间隔基 = C(甲基)C-(甲基)；R = 甲基，对于其他二肟，间隔基 = C[C₄H₈]C、C[C₅H₁₀]C、C[C₆H₁₂]C），形成一种新型的金属 - 配体。所有加成化合物均通过元素分析（碳、氢、氮、氯、铂）、快原子轰击质谱以及红外光谱、¹H、¹³C[¹H]和¹⁹⁵Pt核磁共振光谱进行表征。二甲基甲酰胺双溶剂化物[PtCl₄(NH=C(甲基)ON=C(甲基)C(甲基)=NOH)₂]×2DMF（1a）的X射线结构测定表明其整体为反式构型，丁二酮肟部分呈反式构象，且氮供体配体以脒基单端（而非N,N - 双齿）配位模式存在。当在乙腈中用丁二酮肟处理顺式和反式-[PtC₄(乙腈)₂]的混合物时，相应地观察到顺式和反式-[PtCl₄(NH=C(甲基)ON=C(甲基)C(甲基)=NOH)₂]（1）的形成，并通过¹H、二维[¹H,¹⁵N] HMQC和¹⁹⁵Pt核磁共振光谱监测了在DMSO - d₆溶液中的顺 - 反异构化。尽管从头算计算表明反式构型对于亚氨基酰化物种[PtCl₄-(配体)₂]是有利的，但铂（IV）配合物[PtCl₄(NH=C(甲基)ON=C[C₄H₈]C=NOH)₂]（4）仅以顺式构型分离得到，两个金属 - 配体“臂”通过两个外围羟基之间的分子内氢键结合在一起，单晶X射线衍射法证实了这一点。经典的取代产物，例如[PtC₁₂(N,N - 二肟基)₂]（12 - 15），在加成反应中仅作为次要副产物少量生成；其中两种，[PtCl₂(C₇H₁₁N₂O₂)₂]（14）和[PtCl₂(C₈H₁₃N₂O₂)₂]（15），进行了结构表征。配合物（12 - 15）也通过偕二肟与[PtCl₄L(二甲基亚砜)]（L = 二甲基亚砜、乙腈）反应制备，但单肟（二甲基酮肟、[C₄H₈]C=NOH、[C₅H₁₀]C=NOH、苯甲醛肟、(羟基)C₆H₄C(H)=NOH）与[PtCl₄(乙腈)(二甲基亚砜)]反应不同，生成相应的亚氨基酰化产物[PtCl₄(NH=C(甲基)ON=CRR')(二甲基亚砜)]（7 - 11）。
