ORGANOBORATION OF cis-DIETHYNYLPLATINUM(II) COMPLEXES WITH R2P(CH2)2PR2 LIGANDS: PLATINACYCLOPENTADIENES AND THEIR BEHAVIOUR IN SOLUTION

Article abstract of DOI:10.1016/S0022-328X(00)99693-1

Organoboration of dppePt(C<*>CH)2 (1a) and depePt(C<*>CH)2 (1b) with BR¹₃ (2)(R¹=Me (a), Et₂ (b), or Prⁱ (c)) gives the platinacyclopentadienes, 3a-c and 4c, respectively, in high yield.The stability of 3 in solution increases with the size of R¹.In addition to slow decomposition of 3a (R¹=Me) in solution rearrangement into a platinum-borol complex was observed. 4a (R¹ = Me) decomposes at room temperature, but 4b (R¹ = Et2) reacts readily with an excess of triethylborane to give a new type of platinum-borol complex with an exocyclic BEt2 group and Pt coordination to only one half of the borol ?-system.Variable-temperature 31P NMR shows that rotation of the Pt fragment about the axis linking it to the borol ring is rapid on the NMR time scale.The new compounds have been characterized by 1H, 11B, 13C, 31P and 195Pt NMR spectroscopy.