The reaction of 2,6-[ArN(SiMe3)CH2]2NC5H3 (1, BDPP(SiMe3)2, Ar = 2,6-iPr2C6H3) with TaCl5 yields the complex mer-(BDPP)TaCl3 (2) and 2 equiv of ClSiMe3. The reduction of compound 2 with excess Na/Hg in the presence of alkynes yields the pseudo 5-coordinate Ta(III) derivatives (BDPP)Ta(η2-RC⋮CR‘)Cl (3a, R = R‘ = Pr; 3b, R = R‘ = Et; 3c, R = R‘ = Ph; 3d, R = Ph, R‘ = H). An X-ray study of 3a revealed
2,6- [ArN(SiMe 3)CH 2 ] 2 NC 5 H 3(1,B
DPP(SiMe 3)2,Ar = 2,6- i Pr 2 C 6 H 3)与TACl 5的反应产生复杂聚体- (B
DPP)TACL 3(2 ClSiMe的)和2当量3。化合物的还原2与过量的Na / Hg的
炔烃的存在下产生伪5-坐标的TA(III)衍
生物(B
DPP)TA(η 2 -RC⋮CR ')
氯(3a中,R = R'= PR;3b,R = R′= Et;3c,R = R′= Ph;3d,R = Ph,R′= H)。X射线对3a的研究表明,扭曲的方形
金字塔形几何结构中,
氯化物占据了顶端位置。化合物3A与LIC⋮CR反应得到的
乙炔化辛炔衍
生物(B
DPP)TA(η 2 -PrC⋮CPR)(C⋮CR)(图5a,R = Ph值;图5b,R =卜;图5c,R =森达3 ;在图5d中,R =o- Me 3 SiC 6 H