metalloporphirins; cu(tpp), mn(tpp)cl, co(tpp), fe(tpp)cl, zn(tpp) and mn(obp)cl catalyze region and chemoselective silylation of hydroxyl groups with hmds. fe(tpp)cl is the most effective catalyst and silylation occurs immediately in its presence at room temperature.

to study the existence of clostridium septicum as probable agent associated with currently occurrence of black quarter in urmia area, sheep-dung samples were collected. the bacteriological examinations on suspicious gram positive anaerobic spore-bearing bacilli which are in clostridia genus include isolation and biochemical identification were performed. the results showed 28 different types of...