Phosphorus-centered radicals and biradicals

This thesis deals with the synthesis, reactivity and spectroscopic properties of P-centered mono- and biradicals. First, the addition of aldehydes to the biradical [•P(μ-NTer)2P•], a classical concerted reaction mechanism, was investigated and elucidated in detail. In contrast, radical reactivity for this molecule was observed during the addition of bromoalkanes to [•P(μ-NTer)2P•]. This led to the synthesis of the persistent, phosphorus-centered monoradical [•P(μ-NTer)2PEt], which could also be detected by EPR spectroscopy as an intermediate during the radical reaction mechanism proposed here. Based on the reaction of [•P(μ-NTer)2P•] with bromoalkanes, the bridging of two biradical units was finally achieved with a dibromoalkane. From this, a phosphorus-centered disbiradical was synthesized and its special electronic situation was elucidated by means of extensive EPR experiments and quantum chemical calculations.