Bis(2,4,6-triisopropylphenyl)tin(IV) compounds: Synthesis, single-crystal X-ray characterization and reactivity toward ionizing species and polar monomers

The synthesis of new organotin compounds of general formula Tip(2)SnRR' (Tip = 2 4 6-triisopropyl benzene; R = R' = CH3 (1); R = R'= CH=CH2 (2); R = CH2Ph, R' = Br (3); R = R'= CH2CH=CH, (4)) is described herein. The compounds have been characterized by H-1, C-13, Sn-119 NMR, mass spectroscopy and elemental analysis. Characterization by single-crystal X-ray diffraction analysis has been obtained for compounds 2, 3 and 4. The reactivity with ionizing agents has been studied by NMR spectroscopy. Compounds 2 and 4 underwent alkyl abstraction by [(CH3CH2)(3)Si](+)[B(C6F5)(4)](-) affording stable cationic species (2a, 4a). For the cationic specie 4a a pi-interaction of the benzyl group to the metal centre was recognized by solution NMR studies. A cationic species (3a) was generated from compound 3 using AgSbF6 as ionizing agent. The cationic species (2a, 3a) exhibited moderate activity as initiator in the cationic polymerization of 1,4-butadiene and good activity in the ring opening polymerization (ROP) of propylene oxide and F-caprolactone. (c) 2005 Elsevier B.V. All rights reserved.