T-shaped platinum boryl complexes: synthesis and structure

A series of cationic T-shaped 14-electron boryl complexes of the type trans-(Cy(3)P)(2)Pt{B(X)X'}](+) (X=Br; X'=ortho-tolyl, tBu, NMe(2), piperidyl, Br; XX'=(NMe(2))(2), catecholato) were synthesized by halide abstraction from trans-(Cy(3)P)(2)Pt(Br){B(X)X'}] (Cy=cyclohexyl) with NaBAr(f) (4)] (Ar(f)=3,5-(CF(3))(2)C(6)H(3)), KB(C(6)F(5))(4)], or NaBPh(4)]. X-ray diffraction studies were performed on all compounds, revealing a subtle correlation between the trans-influence of the boryl moiety and the Pt--H and Pt--C separations. However, no notable agostic C--H interaction with the platinum center was detected. trans-(Cy(3)P)(2)Pt(BCat)](+) (Cat=catecholato), the complex with the shortest Pt--H and Pt--C distances, was treated with Lewis bases (L), forming compounds of the type trans-(Cy(3)P)(2)Pt(L)(BCat)](+), thus proving a decisive influence of the degree of trans-influence exerted by the boryl ligands on the chemical reactivity of the title complexes. Another point that was investigated and clarified is the different behavior of trans-(Cy(3)P)(2)Pt(Br){B(Br)Mes}] (Mes=mesityl) towards KB(C(6)F(5))(4)] with formation of the borylene species trans-(Cy(3)P)(2)Pt(Br)(BMes)](+).