Inorganic Chem

Novel Cis- and Trans-Configured Bis(oxime)platinum(II) Complexes: Synthesis, Characterization, and Cytotoxic Activity

Yulia Yu. Scaffidi-Domianello, Kristof Meelich, Michael A. Jakupec, Vladimir B. Arion, Vadim Yu. Kukushkin, Markus Galanski and Bernhard K. Keppler

Inorg. Chem., Article ASAP
DOI: 10.1021/ic100584b
Publication Date (Web): May 11, 2010

Abstract
Novel cis- and trans-configured bis(oxime)platinum(II) complexes have been synthesized and characterized by elemental analyses, IR, electrospray ionization mass spectrometry, multinuclear (1H, 13C, and 195Pt) NMR spectroscopy, and, in five cases, by X-ray diffraction. Their cytotoxicity was studied in the cisplatin-sensitive CH1 cell line as well as in inherently cisplatin-resistant SW480 cancer cells. Remarkably, every single dihalidobis(oxime)platinum(II) complex (with either a cis or trans configuration) shows a comparable cytotoxic potency in both cell lines, indicating a capacity of overcoming cisplatin resistance. Particularly strong cytotoxicities were observed in the case of trans-[PtCl2(R2C═NOH)2] (R = Me, n-Pr, i-Pr) with IC50 values in the high nanomolar concentration range in both CH1 and SW480 cancer cells. These complexes are as potent as cisplatin in CH1 cells and up to 20 times more potent than cisplatin in SW480 cells. In comparison to transplatin, the novel compounds are up to 90 (CH1) and 120 times (SW480) more cytotoxic. The previously reported observation that the trans geometry yields a more active complex in the case of [PtCl2(Me2C═NOH)2] could be confirmed for at least two structural analogues.
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Cesium Hydroperoxostannate: First Complete Structural Characterization of a Homoleptic Hydroperoxocomplex

Andrei V. Churakov, Sergey Sladkevich, Ovadia Lev, Tatiana A. Tripol’skaya and Petr V. Prikhodchenko

Inorg. Chem., Article ASAP
DOI: 10.1021/ic100554u
Publication Date (Web): May 11, 2010

Abstract

The crystal structure of cesium hexahydroperoxostannate Cs2Sn(OOH)6 is presented. The compound was characterized by single crystal and by powder X-ray diffraction, FTIR, 119Sn MAS NMR, and TG-DTA. Cs2Sn(OOH)6 crystallizes in the trigonal space group P, a = 7.5575(4), c = 5.1050(6) Å, V = 252.51(4) Å3, Z = 1, R1 = 0.0120 (I > 2σ(I)), wR2 = 0.0293 (all data), and comprises cesium cations and slightly distorted octahedral [Sn(OOH)6]2− anions lying on the threefold axis. The [Sn(OOH)6]2− unit forms 12 interanion hydrogen bonds resulting in anionic chains spread along the c-axis. All six hydroperoxo ligands are crystallographically equivalent; O−O distances are 1.482(2), only slightly longer than the O−O distance in hydrogen peroxide. FTIR and 119Sn MAS NMR reveal the similarity between all alkali hydroperoxostannates.
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