in dichloromethane under N2 atm. mixt. fc(SiMe2CH2SnMe2CH2SiMe2)2fc and 2 equiv. Me2SnCl2 was stirred for 2 days at 110°C, Me2SnCl2 and Me3SnCl were removed in vacuo, residue was dissolved in CH2Cl2, (PPN)Cl in CH2Cl2 was addedand mixt. was stirred for 1 h; soln. was filtered, hexane was added; elem. anal.;