Organoamidometallics - VI. A new synthetic route to [N,N′-bis(polyfluorophenyl)ethane-1,2-diaminato(2-)]dipyridineplatinum(II) complexes and the preparation of [N-phenyl-N′-(polyfluorophenyl)ethane-1,2-diaminato(2-)] dipyridineplatinum(II) complexes

Article abstract of DOI:10.1016/S0277-5387(97)00310-0

Reaction of [Pt(en)Cl₂] (en = ethane-1.2-diamine) with thallium(I) carbonate (or in some cases K₂CO₃) and a polyfluorobenzene in hot pyridine (py) or 3-methylpyridine (tmpy) yields the [N,N′-bis (polyfluorophenyl)ethane-1,2-diaminato(2-)]platinum(II) complexes, [Pt{N(R)CH₂}₂L₂] (L = py, R = p-HC₆F₄, C₆F₅, p-BrC₆F₄, p-IC₆F₄, p-MeC₆F₄, p-C₆F₅C₆F₄, 2,3,5-F₃C₆H₂, p-O(H)CC₆F₄, p-MeOC₆F₄; L = tmpy, R = p-HC₆F₄). Yields were markedly greater with the use of Tl₂CO₃ than reported for reactions of [Pt(en)Cl₂] with thallium(I) polyfluorobenzoates. A new class of platinum(II) amides, namely [N-(phenyl)-N′-(polyfluorophenyI)ethane-1,2-diaminato(2-)]platinum(II) complexes, [Pt{N(Ph)CH₂CH₂N(R)}L₂] (L = py, R = p-HC₆F₄, C₆F₅, p-MeC₆F₄, p-ClC₆F₄, P-BrC₆F₄; L = 4-methylpyridine, R = P-HC₆F₄), has been prepared by reaction of [Pt(PhNHCH₂CH₂NH₂)I₂] with Tl₂CO₃ or a thallium(I) polyfluorobenzoate and a polyfluoroaromatic compound in pyridine or 4-methylpyridine. The complexes where R = p-MeC₆F₄, p-ClC₆F₄, p-BrC₆F₄ could be prepared only with Tl₂CO₃, which also provided cleaner products where both routes were used. The crystal structure of [Pt{N(Ph)CH₂CH₂N(p-MeC₆F₄)} (py)₂] has been determined and shows a slightly distorted square planar coordination for platinum, with two amide and two cis pyridine nitrogen donors.