Thèse de doctorat en Géologie
Sous la direction de Jacques Barrau.
Soutenue en 2006
à Toulouse 3 .
Le premier chapitre est une mise au point bibliographique concernant les espèces divalentes hétéroleptiques halogénées stabilisées par le ligand b-diiminate L2(Cl)Ge ainsi que des dérivés germaniés porteurs de ligands type «pince» O-chélatants. Le deuxième chapitre concerne les complexes Germanium(II)-Tungstène [L2(X)Ge]nW(CO)6-n (L2 = NPhC(Me)CHC(Me)NPh ; n = 1, 2, X = Cl) ainsi que les réactions de métathèse avec des anions moins coordinants (TfO-, BPh4-, PF6-) pour accéder aux complexes cationiques correspondants. Le troisième chapitre présente des nouveaux composés du Germanium(IV) ArCH2GeHnS3-n (Ar = 2-(MeO)C6H4 ou 5-(Cl)-2-(MeO)C6H3 ; n = 0 et 3, S = X, Me, Ph, OMe ; n = 1, S = X, Me, Mes, OMe, OTf ; n = 2, S = Cl). Une étude théorique DFT, la structure RX de ArCH2GeH2OTf ainsi que l’ensemble des études spectroscopiques montrent que le ligand est O-coordonné au Germanium. Ce chapitre décrit les nouvelles espèces divalentes dérivées ainsi qu’un nouveau cluster à 9 germanium(II).
Non usual coordinences of Germanium : I. Germanium(II)-Tungsten complexes [L2(X)Ge]nW(CO)6-n stabilized by the b-diketiminato ligand L2 ; to the cationic complexes [L2Ge+]nW(CO)6-n (L2 = NPhC(Me)CHC(Me)NPh ; n = 1, X = OTf ; n = 2, X = Cl).II. Study of Germanium(IV) and Germanium(II) species stabilized with the 2-methoxybenzyl ligand ArCH2GeHnS3-n and ArCH2GeCl (Ar = 2-(MeO)C6H4 ou 5-(Cl)-2-(MeO)C6H3 ; n = 0 and 3, S = X, Me, Ph, OMe ; n = 1, S = X, Me, Mes, OMe, OTf ; n = 2, S = Cl)
The first chapter is a bibliographic review situating the work in the general context of halogenated heteroleptic divalent species L2(Cl)Ge stabilized by the b-diketiminato ligand L2 and germanium derivatives bearing O-chelating “pincer” type ligands. The second chapter concerns the Germanium(II)-Tungsten complexes [L2(X)Ge]nW(CO)6-n (L2 = NPhC(Me)CHC(Me)NPh ; n = 1, 2, X = Cl). Metatesis reactions with low coordinating anions (TfO-, BPh4-, PF6-) were envisaged to obtain the corresponding cationic species [L2Ge+]nW(CO)6-n. The third chapter presents new Germanium(IV) compounds ArCH2GeHnS3-n (Ar = 2-(MeO)C6H4 ou 5-(Cl)-2-(MeO)C6H3 ; n = 0 et 3, S = X, Me, Ph, OMe ; n = 1, S = X, Me, Mes, OMe, OTf ; n = 2, S = Cl). X-Ray structure and DFT theoretical study of ArCH2GeH2OTf and all the spectroscopic studies show that the ligand is O-coordinated to the Germanium. The description of new divalent heteroleptic derivatives and a new type of cluster with 9 Germanium(II) is also presented.
The structural evolution related to the uplift of the Andean Cordillera between 33 and 35ºS is well known in the eastern Argentinean flank of the belt, in which it has been developed an east vergent thrust system. In turn, deformation in the Chilean flank of the chain has not been very well constrained and several discrepancies exist in order to explain uplift and Central Depression development. This study shows that in the Andes of Central Chile, compressive deformation consisted in a tectonic inversion accommodating ca. 16 km shortening between 22 and 16 Ma. This shortening is much lesser than that accumulated in the eastern flank of the chain (1/5 of total shortening), in which more than 70 km of shortening has been accommodated between 16 and 4 Ma. Compressive tectonics and Andean uplift in Central Chile were diachronic. Surface uplift mainly occurred between 8 and 4 Ma, that is, several million years after deformation occurred in the Chilean flank of the belt. In fact, surface uplift essentially was the result of deep thickening because of an east-vergent detachment fault located at 10 km depth beneath the Principal Cordillera, which connects to the Benioff zone at 60 km depth through a ramp. This “ramp-flat” structure and its geometry are both controlled by lithospheric rheology. Moreover, this structure would have been essential during Andean evolution because it controls strain and stress transference from the subduction zone toward the continent, and because the flat segment facilitates shortening transfer at deep from higher deformed zones at surface. Therefore, this deformation mode in “simple-shear” would be the responsible for forearc uplift not only in Central Chile, but also along most of the Andean margin. . .