Synthesis of dimethylplatinum(IV) compounds, [{PtMe₂X₂}_n], [{PtMe₂XY}_n], and, in solution,fac-[PtMe₂X(H₂O)₃]⁺, where X and Y are anionic ligands

Supramolecular Polymer and Sheet and a Double Cubane Structure in Platinum(IV) Iodide Chemistry: Solution of a Longstanding Puzzle

“…The reaction immediately gave an insoluble brown precipitate, identified as mostly the known complex 9 . 4 Filtration of the mixture, followed by slow diffusion of ether into the acetonitrile solution, then gave orange crystals identified as complex 8 . 4 The formation of 8 requires a methyl-transfer reaction to form the trimethylplatinum(IV) groups and should also give a monomethylplatinum complex which was not identified.…”

“…7 This paper describes the synthesis and structures of some new platinum(IV) iodide complexes and their supramolecular chemistry. In this study, crystals of the Hall cluster [(PtIMe 3 ·PtI 2 Me 2 ) 2 ] were obtained, 4 and it is finally proved after 47 years to have the double cubane structure D .…”

“…1 Many related complexes have since been reported and they have the classic cubane structure [(PtXMe 3 ) 4 ], A , Chart 1, typically with X – = halide, OH – , SR – , in which each platinum(IV) center is octahedral and each anion is triply bridging. 2−4 There are also dialkylplatinum dihalides [(PtX 2 R 2 ) n ], including those with R = Me and R 2 = C 3 H 6 (the first metallacyclobutane complex), and mixed complexes [(PtXMe 3 ·PtX 2 Me 2 ) n ]. 4−6 On the basis of vibrational spectroscopy and mass spectrometry, as well as by analogy to the established structure A , the complexes [(PtXMe 3 ·PtX 2 Me 2 ) n ] and [(PtX 2 R 2 ) n ] were assigned cubane structures such as B or C , respectively, with two ( B ) or four ( C ) terminal Pt–X bonds as well as the four Pt 3 (μ 3 -X) groups.…”

“…2−4 There are also dialkylplatinum dihalides [(PtX 2 R 2 ) n ], including those with R = Me and R 2 = C 3 H 6 (the first metallacyclobutane complex), and mixed complexes [(PtXMe 3 ·PtX 2 Me 2 ) n ]. 4−6 On the basis of vibrational spectroscopy and mass spectrometry, as well as by analogy to the established structure A , the complexes [(PtXMe 3 ·PtX 2 Me 2 ) n ] and [(PtX 2 R 2 ) n ] were assigned cubane structures such as B or C , respectively, with two ( B ) or four ( C ) terminal Pt–X bonds as well as the four Pt 3 (μ 3 -X) groups. 4,5 These halide complexes are insoluble in noncoordinating solvents, and it was not possible to grow crystals to confirm the proposed structures crystallographically.…”

“…4−6 On the basis of vibrational spectroscopy and mass spectrometry, as well as by analogy to the established structure A , the complexes [(PtXMe 3 ·PtX 2 Me 2 ) n ] and [(PtX 2 R 2 ) n ] were assigned cubane structures such as B or C , respectively, with two ( B ) or four ( C ) terminal Pt–X bonds as well as the four Pt 3 (μ 3 -X) groups. 4,5 These halide complexes are insoluble in noncoordinating solvents, and it was not possible to grow crystals to confirm the proposed structures crystallographically. More recently, the complexes [{Pt(OH)Me 3 ·Pt(OH) 2 Me 2 } 2 ] and [{Pt(OH)Me 3 ·Pt(OMe) 2 Me 2 } 2 ] were prepared and shown to have the double cubane structure D , X = OH or OMe, which contain no terminal Pt–X bonds.…”