* Chromium carbonyl
* Ferrocyanide
* Iron pentacarbonyl
* Nickel carbonyl
* Tetrakis(triphenylphosphine)palladium(0)
* Ferrocene
* Uranium hexafluoride
* tetraethyl lead
* tetramethyl lead
* tetrabutyl tin
* trimethylaluminium
* dimethylmercury
* Diethylzinc
* triethylborane
* Chromate 
* Permanganate 
* Ferroin
* bis(terpyridine)iron(II)