A novel {FeI–FeII–FeII–FeI} iron thiolate carbonyl assembly which electrocatalyses hydrogen evolution

A novel tetra-iron thiolate carbonyl assembly is described in which two dithiolate tetracarbonyl di-iron centres with a ʹbutterflyʹ configuration of the {2Fe3S}-cores are fused by two bridging thiolates which form a central planar 2Fe2S unit and comprise the first example of a chain of four metal–metal bonded iron atoms supported by a bridging sulfur framework; the assembly electrocatalyses hydrogen evolution.