Polynuclear Hydroxido-Bridged Complexes of Platinum(IV) with Terminal Nitrato Ligands

Danila Vasilchenko; Semen Berdugin; Sergey Tkachev; Iraida Baidina; Galina Romanenko; Olga Gerasko; Sergey Korenev

doi:10.1021/ic502896s

Polynuclear Hydroxido-Bridged Complexes of Platinum(IV) with Terminal Nitrato Ligands

Inorg Chem. 2015 May 18;54(10):4644-51. doi: 10.1021/ic502896s. Epub 2015 Apr 24.

Authors

Danila Vasilchenko^{1

2}, Semen Berdugin², Sergey Tkachev¹, Iraida Baidina¹, Galina Romanenko³, Olga Gerasko¹, Sergey Korenev^{1

2}

Affiliations

¹ †Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Science, 630090 Novosibirsk, Russian Federation.
² ‡Novosibirsk State University, 630090 Novosibirsk, Russian Federation.
³ §International Tomography Centre, Russian Academy of Sciences, 630090 Novosibirsk, Russian Federation.

PMID: 25910218
DOI: 10.1021/ic502896s

Abstract

For the first time the polynuclear hydroxido-bridged platinum(IV) nitrato complexes with nuclearity higher than two were isolated from nitric acid solutions of [Pt(H2O)2(OH)4] and crystallized as supramolecular compounds of macrocyclic cavitands cucurbit[n]uril (CB[n], n = 6,8) and 18-crown-6 ether: [Pt4(μ3-OH)2(μ2-OH)4(NO3)10]·CB[6]·25H2O (I), [Pt6(μ3-OH)4(μ2-OH)6(NO3)12](NO3)2·CB[8]·50H2O (II), and [H3O⊂18-crown-6]2[Pt2(μ2-OH)2(NO3)8][Pt4(μ3-OH)2(μ2-OH)4(NO3)10] (III). The isolation of the compounds in the single crystalline state allows the determination of the structure of the tetranuclear and hexanuclear complexes [Pt4(μ3-OH)2(μ2-OH)4(NO3)10] and [Pt6(μ3-OH)4(μ2-OH)6(NO3)12](2+), which have been previously unknown in the solid state. Stability of Ptx(OH)y cores of the polynuclear nitrato complexes toward alkaline hydrolysis was verified by (195)Pt NMR spectroscopy. Analysis of (195)Pt NMR spectra of the compound III reveals that addition of every Pt(μ-OH)2Pt ring results in ∼260 ppm downfield shift relative to the mononuclear form, which allows the prediction of signal positions for complexes of higher nuclearity.