Grignard Synthesis of Triphenylmethanol Lab Report Essay
Organic Chemistry Lab II
March 19, 2012
Abstract The purpose of this experiment was to synthesize the Grignard reagent, phenyl magnesium bromide, and then use the manufactured Grignard reagent to synthesize the alcohol, triphenylmethanol, by reacting with benzophenone and protonation by H3O+. The triphenylmethanol was purified by recrystallization. The melting point, Infrared Spectroscopy, 13C NMR, and 1H NMR were used to characterize and confirm the recrystallized substance was triphenylmethanol.
A Grignard reagent is a type of organometallic, which consists of a bond between a metal and a carbon. There are three types of carbon-metal bonds: ionic, polar covalent, and …show more content…
A dry reflux apparatus is used to heat a solution without gaining any water from the atmosphere. Reflux is the cycle of a liquid going through vaporization and condensation. In order to speed up reactions or to increase the solubility of a compound, chemists often times reflux reaction mixtures. This step implies that the reaction mixture is brought to a boil. The lowest boiling compound in the mixture determines the temperature when this occurs, usually the solvent. It condenses and returns into the reaction vessel (3). There are some other benefits to using a reflux apparatus. First, molecules dissolve faster in heated liquids because the molecules are moving faster and thus collide faster and more often. Second, the heat needed to cause the solution to reflux is energy that can assist molecules in acquiring enough energy to overcome the activation energy barrier to go from liquid to vapor. The liquid in the flask boils, vaporizes, and then hits the cool condenser and condenses back into the flask. The water running through the condenser keeps it cool and allows the vapors rising out of the reaction vessel to condense and drip back down into the solution. The CaCl2 in the drying tube keeps any water from the atmosphere from entering the system. The set up of a dry reflux apparatus is a round bottom flask clamped