Syntheses of [Pt6(CO)8(SnCl2)(SnCl3)4]4- and [Pt6(CO)8(SnCl2)(SnCl3)2(PPh3)2]2- Platinum-Carbonyl Clusters Decorated by SnII Fragments

The reaction of [Pt₆(CO)₆(SnCl₂)₂(SnCl₃)₄]^4- ( 1) with CO under atmospheric pressure resulted in the new [Pt₆(CO)₈(SnCl₂)(SnCl₃)₄]^4- ( 2) cluster by the addition of two CO ligands and the elimination of a stannylene SnCl₂ group. In turn, 2 reacted with 2 equivalents of PPh₃ under a CO atmosphere to afford [Pt₆(CO)₈(SnCl₂)(SnCl₃)₂(PPh₃)₂]^2- ( 3) by elimination of two stannyl [SnCl₃]^- ligands. Conversely, the reaction of 2 with 2 equivalents of PPh₃ under a N₂ atmosphere resulted in a species tentatively formulated as [Pt₆(CO)₅(SnCl₂)₂(SnCl₃)₂(PPh₃)₂]^2- ( 4- 5CO) on the basis of ¹³C NMR, ³¹P NMR spectroscopy and ESI-MS studies. Compounds 2- 4 were spectroscopically characterized by IR spectroscopy and multinuclear (¹³C and ³¹P) variable-temperature NMR spectroscopy. The crystal structures of 2 and 3 were determined by means of single-crystal X-ray diffraction, and their bonding was computationally investigated by DFT calculations. The possible structure of 4- 5CO was predicted by means of DFT methods. [ABSTRACT FROM AUTHOR]