Triphenylmethanol Synthesis Lab Report

The purpose of this experiment was to synthesize triphenylmethanol (TPM), purify it by recrystallization, and to evaluate its purity using melting points and IR/NMR spectrums. In comparing the standard IR spectrum to that of the synthesized products, similar peaks were observed. A small, broad peak at 3500 cm-1 indicated the presence of a O-H bond. The small peaks to the left of 3000 cm-1 suggested the presence of C-H sp2 aromatic bonds. Additionally, a small peak at 1600 cm-1 indicated C=C bonds. When the NMR spectrums for the standard and synthesized product were compared, similar peaks were observed as well. One small peak at 2-3 ppm and one large peak at 7-8 ppm was present. These similarities in spectrum patterns implies that the target molecule, triphenylmethanol, was indeed synthesized and was relatively pure. This conclusion was further supported by the product’s melting

This resulted in a 7.2% yield of pure TPM and a percent recovery of 16%. Evidently, TPM was lost throughout the experiment and/or it was not completely synthesized. The first crude yield of 69% suggests that loss of product may have occurred during the synthesis of TPM and/or the washing/extraction process. Some of the magnesium may not have reacted with the bromobenzene to yield the Grignard reagent. Additionally, the Grignard may not have completely reacted with the benzophenone, which may not have hydrolyzed entirely. Unreacted bromobenzene and Grignard reagent would have resulted in the formation of a biphenyl side product. Because Grignard reagents readily reacts with protic solvents, an anhydrous environment was required. Exposure to atmospheric humidity may have decomposed the reagent, thus further limiting TPM yield. Furthermore, during the liquid-liquid extraction, the alkoxide salt may not have reacted completely with HCl, causing it to be loss in the aqueous