The Parent Diarsene HAs=AsH as Side-on Bound Ligand in an Iron Carbonyl Complex.

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) }As(SiMe ) ] (1) the synthesis of [{Fe(CO) }(η -As H )] (2) is reported, containing a parent diarsene as unprecedented side-on coordinated ligand. Following this synthetic route, also the D-labeled complex [{Fe(CO) }(η -As D )] (2D) could be isolated.