Stereochemistry of oxidative addition of methyl iodide and hydrogen peroxide to organoplatinum(II) complexes having an appended phenol group and the supramolecular chemistry of the platinum(IV) products

Publication date: Available online 27 September 2019Source: Journal of Organometallic ChemistryAuthor(s): Ava Behnia, Mahmood Azizpoor Fard, Richard J. PuddephattAbstractThe oxidative addition chemistry of cycloneophylplatinum (II) complexes containing ligands with an appended phenol group is reported. The platinum (II) complexes [Pt (CH2CMe2C6H4) (L)] with L = 2-C6H4NCHN-2-C6H4OH (L1) or 2-C6H4NCH2–NH-n-C6H4OH (L2, n = 2; L3, n = 3; L4, n = 4) react with MeI or H2O2 to give the corresponding platinum (IV) complexes [PtIMe(CH2CMe2C6H4) (L)] or [Pt (OH)2(CH2CMe2C6H4) (L)], respectively. NMR studies indicate that methyl iodide initially gives trans oxidative addition, but the initial products isomerize rapidly, often to give complex mixtures. The crystalline products all have structures with cis orientation of the PtIMe unit, whose formation is thought to require two isomerization steps after the initial oxidative addition. In contrast, the oxidative addition of H2O2 occurs with trans stereochemistry and no subsequent isomerization is observed. The iodoplatinum (IV) complexes [PtIMe(CH2CMe2C6H4) (L)] form intramolecular OH.I hydrogen bonds (L1) or intermolecular OH.I hydrogen bonds to give head-to-tail dimers (L2 or L4), or a hydrogen bond to solvent (L3). The complex [Pt (OH)2(CH2CMe2C6H4) (L4)] forms an unusual racemic supramolecular polymer with multiple OH.O and NH O hydrogen bonds.Graphical abstract

Source: Journal of Organometallic Chemistry - September 29, 2019 Category: Chemistry Source Type: research