Well stabilized but highly strained masked transitionmetal frustrated Lewis pairs

Resumen del póster presentado a la XXXVIII Reunión Bienal de la Real Sociedad Española de Química, celebrada en el Palacio de Congresos de Granada, del 27 de junio al 30 de junio de 2022.Ligand design plays a preeminent role in organometallic chemistry. Obtaining the desired properties of an organometallic compound often depends on the judicious selection of the stereoelectronic features of the ligands. In the present work it is revealed how the preparation and properties of transition metal frustrated Lewis pairs (TMFLPs) are determined by the nature of the ligands employed. Frustrated Lewis pairs (FLPs) are intra- or inter-molecular systems in which a Lewis acid and a Lewis base do not yield the classical Lewis acid/base adduct because of steric and/or electronic factors. The interest of this type of compound lies in the novel cooperative reactivity between their acidic and basic components that encompasses a variety of stoichiometric and catalytic molecular activation processes. In the first reported examples, the roles of Lewis acid and Lewis base were played by main group elements but the potential of these systems strongly increased with the incorporation of components based on transition metals resulting in the socalled TMFLPs. For some FLP systems, the equilibrium between the dissociated acid and base and the classical Lewis acid/base adduct was detected. Interestingly, FLP reactivity has been observed even when the equilibrium was almost completely shifted toward the classical Lewis acid-base adduct, provided that the dissociated state was thermally accessible. To refer to the involved FLPs, the qualifying term “masked” was introduced.Here we describe the preparation of the pyridinyl-guanidine compounds H2L1 and H2L2 (Figure 1: Pyridinyl-guanidine ligands) and their application as ligands to the synthesis of new TMFLP compounds. Likewise, a detailed analysis of the structural features of these compounds that allow them to give rise to half-sandwich compounds of rhodium and iridium with FLP properties will be carried out. Some examples of the FLP reactivity of these organometallic compounds are also reported.Peer reviewe