Tham khảo tài liệu 'dendrimers ii episode 5', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | The First Organometallic Dendrimers Design and Redox Functions Didier Astruc1 Jean-Claude Blais2 Eric Cloutet1 Laurent Djakovitch1 Stéphane Rigaut1 Jaime Ruiz1 Valérie Sartor1 Christine Valério1 1 Groupe de Chimie Supramoléculaire des Métaux de Transition LCOO UMR CNRS No. 5802 Université Bordeaux 1 33405 Talence Cédex France E-mail 2 Laboratoire de Chimie Structurale Organique et Biologique EP CNRS No 103 Université Paris VI 4 Place Jussieu 75252 Paris France This review summarizes our original organometallic route to stars dendrimers metallostars and metallodendrimers and the redox functions of these macromolecules in catalysis and anionic recognition. The synthesis of metal-sandwich stars and dendritic cores was achieved using the CpM induced polyallylation and polybenzylation of polymethylbenzenes M Fe or Ru and pentamethylcyclopentadienyl ligands M Co or Rh . Subsequent functionalization of the polyallyl dendritic cores yielded polyols which are precursors of polyiodo polymesylates polynitriles polyamines and polybenzaldehaldehyde cores. The synthesis of dendrimers up to 144-nitrile and 243-allyl was subsequently achieved starting from mesitylene. Functionalization of the polybenzyl dendritic cores was achieved by regiospecific Friedel-Crafts reactions acetylation chlorocarbonylation in the para position. Various metallodendrimers were synthesized with amidoferrocene amidocobaltocenium and FeCp 6-N-alkylaniline termini in which the redox centers show a reversible behavior and are all independent as observed by cyclic voltammetry. The 9- 18- and 24-amidometallocene dendrimers were used for the recognition of the oxo anions H2PO- and HSO- by cyclic voltammetry whereas a 24-iron-alkylaniline dendrimer was efficient to recognize Cl- and Br- anions by 1H NMR with sharp dendritic effects. Differences between the responses to the different anions were large and the largest effects were found for the 18-Fc dendrimer dendritic effect . A .
