in tetrahydrofuran addn. of equimolar amt. of cyclopropene to soln. of K-salt in THF at ambient temp. under N2; stirring for 15 min;; the carbene complex was not isolated but detected in soln. by IR spectroscopy; concn., addn. of toluene, filtration, crystn. from toluene/petroleum ether at -78°C or chromy. on silica at -10°C yield the CrSn- and C6H6Cr(CO)3 complexes;;
