Stoichiometric molecular single source precursors to cobalt phosphides

Crystalline cobalt phosphides were synthesized by using three different, low oxidation-state organometallic clusters as precursors, [Co4(CO)10(μ-dppa)], [Co4(CO)10(μ4-PPh)2] and [Co4(CO)8(μ-dppa)2] (dppa = Ph2PNHPPh2), which are characterized by Co/P ratios of 2:1, 2:1 and 1:1, respectively. Depending on their Co/P ratio, these clusters are suitable single-source precursors to form CoP and Co2P without the need to add any other reagent or surfactant. The thermal behavior of these three clusters was investigated under different conditions. The results show how their Co/P ratios, the nature of the atmosphere used for their thermal activation and the temperature control the nature and composition of the resulting phases.