Heteroleptic Chini-Type Platinum Clusters: Synthesis and Characterization of Bis-Phospine Derivatives of [Pt3n(CO)6n]2– (n = 2–4)

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• 作者：Cristiana Cesari ; Iacopo Ciabatti ; Cristina Femoni ; Maria Carmela Iapalucci ; Federica Mancini ; Stefano Zacchini
• 刊名：Inorganic Chemistry
• 出版年：2017
• 出版时间：February 6, 2017
• 年：2017
• 卷：56
• 期：3
• 页码：1655-1668
• 全文大小：653K
• ISSN：1520-510X

文摘

The reactions of [Pt_3n(CO)_6n]^2– (n = 2–4) homoleptic Chini-type clusters with stoichiometric amounts of Ph₂PCH₂CH₂PPh₂ (dppe) result in the heteroleptic Chini-type clusters [Pt₆(CO)₁₀(dppe)]^2–, [Pt₉(CO)₁₆(dppe)]^2–, and [Pt₁₂(CO)₂₀(dppe)₂]^2–. Their formation is accompanied by slight amounts of neutral species such as Pt₄(CO)₄(dppe)₂, Pt₆(CO)₆(dppe)₃, and Pt(dppe)₂. A similar behavior was observed with the chiral ligand R-Ph₂PCH(Me)CH₂PPh₂ (R-dppp), and two isomers of [Pt₉(CO)₁₆(R-dppp)]^2– were identified. All the new species were spectroscopically characterized by means of IR and ³¹P NMR, and their structures were determined by single-crystal X-ray diffraction. The results obtained are compared to those previously reported for monodentate phosphines, that is, PPh₃, as well as more rigid bidentate ligands, that is, CH₂═C(PPh₂)₂ (P^P), CH₂(PPh₂)₂ (dppm), and o-C₆H₄(PPh₂)₂ (dppb). From a structural point of view, functionalization of anionic platinum Chini clusters preserves their triangular Pt₃ units, whereas the overall trigonal prismatic structures present in the homoleptic clusters are readily deformed and transformed upon functionalization. Such transformations may be just local deformations, as found in [Pt₉(CO)₁₆(dppe)]^2–, [Pt₉(CO)₁₆(R-dppp)]^2–, [Pt₁₂(CO)₂₂(PPh₃)₂]^2–, and [Pt₉(CO)₁₆(PPh₃)₂]^2–; an inversion of the cage from trigonal prismatic to octahedral, as observed in [Pt₆(CO)₁₀(dppe)]^2– and [Pt₆(CO)₁₀(PPh₃)₂]^2–; the reciprocal rotation of two trigonal prismatic units with the loss of a Pt–Pt contact as found in [Pt₁₂(CO)₂₀(dppe)₂]^2–.