ABSTRACT
The terminal diarsene HAs=AsH ligand attracts special interest concerning its bonding relation in comparison to its isolable relative, ethene. Herein, by the methanolysis of [{Fe(CO)4 }As(SiMe3 )3 ] (1) the synthesis of [{Fe(CO)4 }(η2 -As2 H2 )] (2) is reported, containing a parent diarsene as unprecedented side-on coordinated ligand. Following this synthetic route, also the D-labeled complex [{Fe(CO)4 }(η2 -As2 D2 )] (2D) could be isolated. The electronic structure and bonding situation of 2 was elucidated by DFT calculations revealing that 2 is best described as an olefin-like complex. Moreover, the reactivity of 2 towards the Lewis acids [{M(CO)5 }(thf)] (M=Cr, W) was investigated, leading to the complexes [Fe(CO)4 AsHW(CO)5 ]2 (3) and [{Fe(CO)4 }2 AsH{Cr(CO)5 }] (4), respectively.
