Vipin Kumar Saini - Carbosilane dendrimers with end-grafted silacrown- and crown-ether units

Version 1

      Publication Details (including relevant citation   information):

      Published in Synthesis, (8), 1243-1248(2004). (Impact factor   2.57) (Citations 3)


      The synthesis of the vinyl-functionalized silacrown ethers   1-methyl-1-vinylsila-8-crown-3 (3) and   1-methyl-1-vinylsila-11-crown-4 (4) by the   reaction of (H2C=CH)MeSi(OEt)2 (1) with   HO(CH2CH2O)nH (2a, n = 2; 2b, n = 3) in   presence of catalytic amounts of NaOMe is described. These   species can be attached to 1st and 2nd  generation carbosilane dendrimers by hydrosilylation. Treatment   of   Si(CH2CH2CH2SiMe2H)4  (5) or   Si[CH2CH2CH2Si-Me(CH2CH2CH2SiMe2H)2]4  (8) with 3 or   4 produces the respective silacrown ether   end-grafted carbosilane dendrimers 6,   7, 9 and 10 in nearly quantitative yield. In a similar manner   2-allyloxymethyl-12-crown-4 (11) gives with   5 and 8 the   12-crown-4 end-capped carbosilane dendrimers 12 and 13, respectively.

      The formation of analytical pure and uniform carbosilane   dendrimers  with crown ethers at the periphery is based on   elemental analysis, IR, 1H,   13C{1H} and 29Si{1H}   NMR spectroscopy. ESI-TOF MS studies reveal that 7, 10, 12  and 13 form complexes with alkali ions,   which enables such species to function as possible ionophores for   chemical sensors.

      Address (URL): http:// -2004-822349