The syntheses of the new compounds [W(η-C5H5)(η-C5H4B(C6F5)2R})H3], where R = (C6F5) 1, Ph 2, H 3 or Cl 4, [Mo(η-C5H5)2(H)(η1-HB(C6F5)3)] 5, [Mo(η-C5H5)2(H)(η1-H2B(C6F5)2)] 6, [Mo(η-C5H4Me)2(H)(η1-HB(C6F5)3)] 7, [Re(η-C5H5)(η-C5H4B(C6F5)3)H2]·0.5C6H5Me 8, [Ta(η-C5H5)2(H)2(η1-HB(C6F5)3)] 9 and [Re(η-C5H5)(η-C5H4B(C6F5)2})(C6F5)] 10 are described. The crystal structures of compounds 4 and 10 have been determined. Initial electrophilic addition of the Lewis acid B(C6F5)3 occurs either by exo-addition to a carbon of a η-cyclopentadienyl ring with formation of an exo-(C6F5)3B}C5H5, or by formation of an Mâμ-HâB two-electron three-centre bond.
新化合物[W(δ--
C5H5)(δ--
C5H4B(
C6F5)2R})H3]的合成,其中 RÂ =Â ( ) 1, Ph 2, H 3 或 Cl 4, [Mo(δ- )2(H)(δ-1-HB( )3)] 5、[Mo(δ-- )2(H)(δ-1-H2B( )2)] 6, [Mo(δ-- Me)2(H)(δ-1-HB( )3)] 7, [Re(δ-- )(δ-- B( )3)H2]Â-0.5C6H5Me 8、[Ta(δ-- )2(H)2(δ-1-HB( )3)]9 和[Re(δ-- )(δ-- B( )2})( )]10。化合物 4 和 10 的晶体结构已经确定。
路易斯酸 B( )3最初的亲电加成是通过外加到δ-
环戊二烯环的一个
碳上,形成一个外加( )3B} ,或者形成一个Mâμ-HâB双电子三中心键。