The reaction of Mo2Br2(CO)2(PPh3)2 with aqueous NaBF4 in CH2Cl2 leads to [Mo2(μ-X)(μ-F)2(CO)4(PPh3)4]+ (X Br, F, Cl, OH). The initially formed bromide can be isolated under appropriate conditions and crystallographically characterized as the unusual fluroide salt [Mo2(μ-Br)(μ-F)2(CO)4(PPh3)4]F (x hexane). The molecular unit is a triply bridged dimer with very long MoBr distances [2.694(3) and 2
MO 2 Br 2(CO)2(PPh 3)2与NaBF 4
水溶液在CH 2 Cl 2中的反应产生[MO 2(μ-X)(μ-F)2(CO)4(PPh 3)4 ] +(XBr,F,Cl,OH)。可以在适当的条件下分离初始形成的
溴化物,并在晶体学上表征为不寻常的
氟化物盐[MO 2(μ-Br)(μ-F)2(CO)4(PPh 3)4] F(x己烷)。该分子单元是三键桥接的二聚体,具有非常长的MOBr距离[2.694(3)和2.693(3)Å],这是由两个几乎共线的CO
配体的反式影响所致(BrMO CO约165°)。
溴是通量的,从可变温度31 P NMR光谱中可以明显看出MOBr的裂解过程。在反应条件下,
溴化物被排出,从而形成[MO 2(μ-X(μ-F)2(CO)4(PPh 3)4 ] +(XF,Cl,OH)。 WBr 2(CO)2(PPh 3)2反应形成[W(μ-F)n(μ-Br) 3−