title: Platinum(IV)-mediated nitrile-sulfimide coupling: a route to heterodiazadienes.
abstract: Pt(IV)-mediated addition of the sulfimide Ph2S = NH and the mixed sulfide/sulfimides o- and p-[PhS(=NH)](PhS)-C6H4 by the S=NH group to the metal-bound nitriles in the platinum(IV) complexes [PtCl4(RCN)2] proceeds smoothly at room temperature in CH2Cl2 and results in the formation of the heterodiazadiene compounds [PtCl4[NH=C(R)N=SR'Ph]2] (R' = Ph, R = Me, Et, CH2Ph, Ph; R' = o- and p-(PhS)C6H4; R = Et). While trans-[PtCl4(RCN)2] (R = Et, CH2Ph, Ph) reacting with Ph2S=NH leads exclusively to trans-[PtCl4[NH=C(R)N=SPh2]2], cis/trans-[PtCl4(MeCN)2] leads to cis/trans mixtures of [PtCl4[NH=C(Me)N=SPh2]2] and the latter have been separated by column chromatography. Theoretical calculations at both HF/HF and MP2//HF levels for the cis and trans isomers of [PtCl4[NH=C(Me)N=SMe2]2] indicate a higher stability for the latter. Compounds trans-[PtCl4[E-NH=C(R)N=SPh2]2] (R = Me, Et) and cis-[PtCl4[E-NH=C(Me)N=SPh2][Z-NH=C(Me)N=SPh2]] have been characterized by X-ray crystallography. The complexes [PtCl4[NH=C(R)N=SPh2]2] undergo hydrolysis when treated with HCl in nondried CH2Cl2 to achieve the amidines [PtCl4[NH=C(NH2)R]2] the compound with R = Et has been structurally characterized) and Ph2SO. The heterodiazadiene ligands, formed upon Pt(IV)-mediated RCN/sulfimide coupling, can be liberated from their platinum(IV) complexes [PtCl4[NH=C(R)N=SR'Ph]2] by reaction with Ph2PCH2CH2PPh2 (dppe) giving free NH=C(R)=SR'Ph and the dppe oxides, which constitutes a novel route for such rare types of heterodiazadienes whose number has also been extended. The hybrid sulfide/sulfimide species o- and p-[PhS(=NH)](PhS)C6H4 also react with the Pt(II) nitrile complex [PtCl2(MeCN)2] but the coupling--in contrast to the Pt(IV) species--gives the chelates [PtCl2[M-I=C(Me)N=S(Ph)C6H4SPh]]. The X-ray crystal structure of [PtCl2[M-I=C(Me)N=S(Ph)C6H4SPh-o]] reveals the bond parameters within the metallacycle and shows an unusual close interaction of the sulfide sulfur atom with the platinum.
authors.affiliation: Department of Chemistry, St. Petersburg State University, 198504 Stary Petergof, Russian Federation.
authors.forename: Anastassiya V
authors.initials: AV
authors.lastname: Makarycheva-Mikhailova
authors.forename: Nadezhda A
authors.initials: NA
authors.lastname: Bokach
authors.forename: Vadim Yu
authors.initials: VY
authors.lastname: Kukushkin
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authors.lastname: Kelly
authors.forename: Liam M
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authors.lastname: Gilby
authors.forename: Maxim L
authors.initials: ML
authors.lastname: Kuznetsov
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Holmes
authors.forename: Matti
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authors.lastname: Haukka
authors.forename: Jonathan
authors.initials: J
authors.lastname: Parr
authors.forename: Julia M
authors.initials: JM
authors.lastname: Stonehouse
authors.forename: Mark R J
authors.initials: MR
authors.lastname: Elsegood
authors.forename: Armando J L
authors.initials: AJ
authors.lastname: Pombeiro