Thèse de doctorat en Chimie organiqueChimie organique
Soutenue en 2012
à Rouen en cotutelle avec l'Universitatea Babeș-Bolyai (Cluj-Napoca, Roumanie) , dans le cadre de École doctorale normande de chimie (Caen) , en partenariat avec Chimie organique, bioorganique : réactivité et analyse (Mont-Saint-Aignan, Seine-Maritime ; 1996-....) (laboratoire) .
Our work described in this Ph. D Thesis comprises two parts entitled as Chapters. The research reported in Chapter1 concerns the synthesis and photophysical properties of new fluorophore A-π-D using diazine moiety as π-acceptor. The research reported in Chapter 2 concerns the design, synthesis and structural analysis of some new spiro-dendritic chiral melamines with peripheral units of type serinol / serinol-aminoacetal. The first Chapter presents the synthesis of a new A-π-D fluorophore using Sonogashira cross coupling reaction and copper-catalyzed Huisgen 1,3-dipolar cycloaddition. The target compounds consist of diazines as electron acceptor group A, N,N-dmethylaniline as electron-donating group D and fluorene as a π-conjugated central transmitter. All compounds have been fluorescent. Generally, good quantum yields were obtained, up to 72%, broad Stokes shifts and two-photon absorption cross-section values up to 367 GM. The second Chapter describes the preparation and stereochemistry of new G-0, -1 small dendrimers, seen as "model compounds" for the next investigated iterative syntheses of G-1, -2 target dendrimers. These structures contain, for the first time in the dendritic chemistry, the 7,11,18,21-tetraoxa-3,15-diazatrispiro[5. 2. 2. 5. 2. 2]heneicosan-3,15-diyl chiral skeleton as internal or central linker. The target dendrimers contained C-2 substituted 2-aminopropane-1,3-diols (Serinols, "open-chain" motif) and enantiopures amino-1,3-dioxanes ["closed-chain" motif, derivatives of (1S,2S)-2-amino-1-(4-nitrophenyl)-propane-1,3-diol] as peripheral units. The stereochemistry of rotational phenomena occurring about the C(s-triazine)-N(exocyclic) partial double bonds involving the peripheral units is discussed by means several methods and parameters : NH Gradient Temperatures (GT, from 1H NMR), rotational barriers ΔG* (from VT 1H NMR), hydrodynamic diameteres dH (from 2D-1H DOSY NMR), spatial (dipolar) interactions (from 2D-1H, 1H-NOESY and QC 13C NMR) and optical rotations [α]D20 (polarimetry).