Bpm Synthesis Essay

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The lab report below was submitted as part of the coursework for CM3291 Advanced Experiments in Organic and Inorganic Chemistry. Please do not plagiarise from it as plagiarism might land you into trouble with your university. Do note that my report is well-circulated online and many of my juniors have received soft copies of it. Hence, please exercise prudence while referring to it and, if necessary, cite this webpage. Aim This experiment consists of two parts. The first part involves the synthesis of the bidentate ligand bis(pyrazolyl)methane (bpm). The second part of the experiment involves the bpm reacting in a ligand substitution reaction with molybdenum hexacarbonyl. Results & Calculations Part 1: Synthesis of the ligand (bpm) Molar mass of pyrazole: 2 x 14.01 + 3 x 12.01 + 4 x 1.0079 = 68.08 g mol-1 Molar mass of CH2Br2: 12.01 + 2 x 1.0079 + 2 x 79.90 = 173.83 g mol-1 Molar mass of bpm: 4 x 14.01 + 7 x 12.01 + 8 x 1.0079 = 148.17 g mol-1 Mass of pyrazole: 1.0081 g Number of moles of pyrazole: 1.0081 / 68.08 = 14.81 mmol Volume of CH2Br2: 0.50 ml Density of CH2Br2: 2.477 g ml-1 Mass of CH2Br2: 0.50 x 2.477 = 1.2385 g Number of moles of CH2Br2: 1.2385 / 173.83 = 7.12 mmol As the mole ratio of pyrazole to dibromomethane is 2:1, twice of 7.12 mmol is 14.24 mmol which is less than the number of moles of pyrazole. Thus, this means that dibromomethane was the limiting reagent in the reaction. Mole ration of CH2Br2 to bpm is 1:1. Number of moles of bpm: 7.12 mmol Theoretical mass of bpm: 7.12 x 10-3 x 148.17 = 1.0550 g Actual mass of bpm: 0.6330 g Percentage yield of bpm: 0.6330 / 1.0550 = 60.0% Melting point of bpm: 106.20 – 109.30 oC Part 2: Reaction with Mo(CO)6 Molar mass of Mo(CO)6: 95.94 + 6 x (12.01 + 16.00) = 264.00 g mol-1 Molar mass of Mo(CO)4bpm: 95.94 + 4 x (12.01 + 16.00) + 148.17 =

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