NaHg(x) in tetrahydrofuran byproducts: NaCl; (N2), to cooled NaHg(x) added THF and (Co(CO)3PPh3)2, mixture stirred for 24 h, added to soln. of Sn-compound in THF under N2 (through a filtercovered with glasswool), mixture stirred at room temp. for 12 h; NaCl centrifuged, soln. evapd., chromd. (SiO2, C6H6/petroleum ether (1/3) at 40°C), crystd. with n-hexane, elem. anal.;