Reactivity of Pt(0) bromosilylene complexes towards ethylene.

The base-free carbazolyl bromosilylene RSiBr (R = 1,8-bis(3,5-di- tert -butyl-phenyl)-3,6-di- tert -butyl-carbazolyl) reacts with (η 2 -C 2 H 4 )Pt(PPh 3 ) 2 and Pt(PCy 3 ) 2 to form platinasilacyclobutane R(Br)Si(C 2 H 4 )Pt(PPh 3 ) 2 (1) and silylene platinum complex R(Br)SiPt(PCy 3 ) 2 (2), respectively. When silylene complex 2 is treated with C 2 H 4 , the six-membered metallasilacycle R(Br)Si(C 2 H 4 ) 2 Pt(PCy 3 ) 2 (3) is obtained. All compounds are characterised by XRD and multinuclear NMR spectroscopy.