Reactions of a Phosphinoimino-thiazoline-Based Metalloligand with Organic and Inorganic Electrophiles and Metal-Induced Ligand Rearrangements

The reaction of the neutral Pt(II) bischelated complex cis-[Pt{Ph2PN···C···NCH2CH2S}2] ([Pt(2−H)2], 1; 2 = Ph2PNHCNCH2CH2S, N-(diphenylphosphino)-thiazoline-2-amine) with the organic electrophile EtNCS yielded complex [Pt(2−H)(2−H·EtNCS)] (3) as a result of the nucleophilic attack of the coordinated 2-((diphenylphosphino)imino)thiazolidin-3-yl moiety on the heteroallene carbon atom and coordination of the sulfur atom to the metal. The reaction of 1 with [Cu(NCMe)4]PF6 also proceeded by nucleophilic attack of the P−N nitrogen atom on Cu(I) and afforded the coordination polymer [1·Cu]∞[PF6]∞ (4). The reaction of ligand 2 with NiBr2·xH2O resulted in a molecular rearrangement and afforded an unexpected pentacoordinated diamagnetic complex, [Ni(2){trans-Ph2PNC−N(PPh2)CH2CH2S}Br]Br (6), which likely arises from a metal-templated ligand coupling in the presence of water acting as promoter. Complex 6 was evaluated as a precatalyst for ethylene oligomerization, showing good activities with EADC as cocatalyst. All new complexes were structurally characterized by X-ray diffraction.