Reactivity of a half-lantern Pt2(ii, ii) complex with triphenylphosphine: selectivity in a protonation reaction. Issue 80 (12th August 2016)

• Record Type: Journal Article
• Authors: Niazi, Maryam; Shahsavari, Hamid R.; Haghighi, Mohsen Golbon; Halvagar, Mohammad Reza; Hatami, Samaneh; Notash, Behrouz
• Is Part Of: RSC advances. Volume 6:Issue 80(2016)
• Page Start: 76463
• Page End: 76472
• Publication Date: 2016-08-12
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra15604e
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Reaction of PPh3 with half-lantern complex [{Pt(ppy)(μ2 -Spy)}2 ], 1, gave complex [Pt(ppy)(η 1 -S-Spy)(PPh3 )], 2, as a result of platinum–nitrogen bonds dissociation. Complex2 revealed anionic selectivity upon protonation reaction with acidic species. Abstract : The half-lantern Pt2 (ii, ii ) complex [{Pt(ppy)(μ2 -Spy)}2 ], 1, in which ppyH = 2-phenylpyridine and pySH = pyridine-2-thiol, is treated with two equivalents of triphenylphosphine ligand (dissociated Pt–NSpy bonds) to form complex [Pt(ppy)(η 1 -S-Spy)(PPh3 )], 2 . This complex can alternatively be obtained directly from the reaction of complex [Pt(ppy)(PPh3 )Cl], 3, with an ethanolic solution of sodium pyridine-2-thiolate. The transphobia effect (T) controls the geometry of complex2 and spectroscopic data confirms that the phosphine ligand is positioned trans to the nitrogen atom of the cyclometalating fragment (ppy). The solution dynamics of complex2 was investigated by NMR spectroscopy and it revealed a fluxional behavior in solution. Besides, the protonation reaction conditions for complex2 revealed the sensitivity of this complex to the anionic group of the acidic species. For instance, reaction of complex2 with hydrogen chloride that contains a coordinating anion, resulted in a platinum–sulfur bond cleavage and subsequent formation of the corresponding chloride complex3 . In contrast, upon treatment of complex2 with HPF6, involving a non-coordinating counter-anion, the pendant nitrogen atom was protonated and complex [Pt(ppy)(η 1 -S-Spy * ) (PPh3 )][PF6 ], 5, was obtained.