Résumé:
The geometric parameters and electronic structures of a series of hypothetical compounds of general formula CpM(C13H9N) and (CO)3M(C13H9N) (M = first row transition metal, Cp = C5H5, and C13H9N = benzoquinoline ligand) are investigated by means of the density functional theory. The benzoquinoline ligand can bind to the metal through ɳ1 to ɳ6 coordination mode, in agreement with the electron count and the nature of the metal, showing its capability to adapt itself to the electronic demand of the metal as well as to the polycyclic aromatic hydrocarbons. In the investigated species, the most favored closed shell count is 18-electron except for the Ti and V models which are deficient open-shell 16- electron configuration. This study has shown the difference in coordination ability of this heteropolycyclic ligand: the coordination of the central C5N ring is less favored than the C6 rings, in agreement with the π electron density localization. Most of the investigated complexes are expected to exhibit a rich fluxional behavior. This flexibility favors the possibility for the existence of several isomers as well as their interconversion through haptotropic shifts.
We discussed in the second part, the electronic structure of benzoquinoline of general formula (L3M) 2 (C13H9N) (M = Ti, V, Mn, Cr, Fe, Co and Ni, L3 = (CO) 3 and Cp: C5H5 (C13H9N ligand benzoquinoline). The structures were studied with two syn and anti configurations. The bi-nuclear benzoquinoline complexation occurs on both cycles C6 or C6 cycles and C5N, the modes of coordination (ɳ2 and ɳ6) leading to syn and anti structures, respectively, and agree with the favored 18 electron configurations with a closed shell and 18-/16- EVM with a open shell. This study showed that communication depends on the binding with ligands and the nature of the metal centers and their oxidation state of the attached ligands.
The last chapter includes the study of species formation PtOs (CO) 4 (SnPh3) (PBut3) [μ-HC2 (H) Ph] from the insertion of an alkyne and the complex [IrRu (CO) 4 (.-C = C (H) R') (dppm) 2] [BF4] from an insertion of an alkene. One approaches the behavior of these species there also via structural variations on the ligands, the metal and the alkyne or the alkene, and finally, the reactivity of these substrates with different species or their precursors.
