PPh3‑Derivatives of [Pt3n (CO)6n ]2– (n = 2–6) Chini’s Clusters: Syntheses, Structures, and 31P NMR Studies

• Published in: Inorganic chemistry Vol. 52; no. 8; pp. 4384 - 4395
• Main Authors: Ciabatti, Iacopo, Femoni, Cristina, Iapalucci, Maria Carmela, Longoni, Giuliano, Lovato, Tatiana, Zacchini, Stefano
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 15.04.2013
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/ic3025414

The reaction of the [Pt3n (CO)6n ]2– (n = 2–6) Chini’s clusters with increasing amounts of PPh3 has been investigated in detail by combined FT-IR, 31P{1H} NMR, and electrospray ionization-mass spectrometry (ESI-MS) studies, showing that up to three CO ligands are gradually substituted by PPh3, resulting in isonuclear phosphine-substituted anionic clusters of general formula [Pt3n (CO)6n−x (PPh3) x ]2– (n = 2–6; x = 1–3). Further addition of PPh3 results in the elimination of the neutral Pt3(CO)3(PPh3)3 species and formation of lower nuclearity anionic clusters. [Pt12(CO)22(PPh3)2]2– and [Pt9(CO)16(PPh3)2]2– have been structurally characterized, and they maintain the trigonal prismatic structures of the parent homoleptic clusters, with the two PPh3 ligands bonded to different external Pt3-triangles in relative cis-position. Conversely, the crystal structure of [Pt6(CO)10(PPh3)2]2– shows that its metal cage is transformed from trigonal prismatic to trigonal antiprismatic after CO/PPh3 exchange.