Highly Unsaturated Platinum-Rhenium Cluster Complex Adds an Unusually Large Amount of Hydrogen

General Data. Reagent grade solvents were dried by the standard procedures and were freshly distilled prior to use. Infrared spectra were recorded on a Thermo Nicolet Avatar 360 FT-IR spectrophotometer. 1H NMR and 31P{1H} NMR were recorded on a Varian Mercury 400 spectrometer operating at 400.1 and 161.9 MHz, respectively. 1H NMR spectrum of 2 was recorded on a Varian Inova 500 spectrometer operating at 500.2 MHz. 31P{1H} NMR spectra were externally referenced against 85 % ortho-H3PO4. Electrospray mass spectrometric measurements were obtained on a MicroMass Q-Tof spectrometer. Bis(tri-tert-butyl phosphine)platinum(0), Pt(PBu t3)2, and Re2(CO)10 were obtained from Strem and were used without further purification. Product separations were performed by TLC in air on Analtech 0.25 and 0.5 mm silica gel 60 Å F254 glass plates. Preparation of Pt3Re2(CO)6(PtBu3)3, 1. Under an atmosphere of nitrogen, Re2(CO)10 (29.0 mg, 0.044 mmol) and Pt(PBu t3)2 (160.0 mg, 0.267 mmol) were dissolved in 15 mL of octane. The reaction mixture was heated to reflux for 3 h, after which the solvent was removed in vacuo. The product was separated by TLC using a 3:1 hexane/methylene chloride solvent mixture to yiel