Tlc (Fluorene, 9-Fluorenol, 9-Fluorenone )
1. In table format, provide the Rf values you recorded for each of the 3 compounds in Part I. List compound on one axis of your table and solvent system on the other. If multiple spots were present for a compound, give Rf value for each component and state if the component was major or minor.
| 100% hexane | 25% EtOAc in hexane | 10% EtOAc in hexane | Fluorene | 0.34 cm | 0.94 cm | 0.67 cm | 9 - fluorenol | 0.00 cm | 0.49 cm | 0.05 cm | 9 - fluorenone | 0.00 cm | 0.69 cm | 0.21 cm |
2. Explain how Rf values were generally affected by polarity of the solvent/eluent systems. As part of your answer, rank the solvent/eluent systems in order of decreasing polarity (this can be done according to structure of the individual solvents and % composition of the mixtures). Also rank the 3 compounds in order of decreasing polarity (this compound ranking can be based on structure as well as on these TLC results). Explain each of your rankings.
Compounds: 9-fluorenone, 9-fluorenol. Fluorene Solvent: Ethyl acetate 10% in hexane, Ethyl acetate 25% in hexane, 100% hexane
Polarity of each compound reacted differently to each of the solvents used. As we know, ‘like’ interacts with ‘like’. Fluorene has the least amount of polarity based on structure and when it was mixed with non-polar and slightly polar solvents, its mobile phase moved the furthest. Such that when Fluorene was put in 25% EtOAc, which is 75% polar, its mobile phase was the furthest, followed by 90% polar in 10% EtOAc in hexane, and its most solid phase was in 100% hexane. 9 – fluorenol is the highest polar compound based on structure and when it was mixed with a polar solvent its mobile phase was the slowest, therefore, it did not travel very far up the silica gel plate. When 9-fluorenol was mixed in slightly polar solvent, 10% EtOAc, its mobile phase also did not travel very far. The only time 9-fluorenol mobile phase travelled up the silica gel plate is when it was combined with
| 100% hexane | 25% EtOAc in hexane | 10% EtOAc in hexane | Fluorene | 0.34 cm | 0.94 cm | 0.67 cm | 9 - fluorenol | 0.00 cm | 0.49 cm | 0.05 cm | 9 - fluorenone | 0.00 cm | 0.69 cm | 0.21 cm |
2. Explain how Rf values were generally affected by polarity of the solvent/eluent systems. As part of your answer, rank the solvent/eluent systems in order of decreasing polarity (this can be done according to structure of the individual solvents and % composition of the mixtures). Also rank the 3 compounds in order of decreasing polarity (this compound ranking can be based on structure as well as on these TLC results). Explain each of your rankings.
Compounds: 9-fluorenone, 9-fluorenol. Fluorene Solvent: Ethyl acetate 10% in hexane, Ethyl acetate 25% in hexane, 100% hexane
Polarity of each compound reacted differently to each of the solvents used. As we know, ‘like’ interacts with ‘like’. Fluorene has the least amount of polarity based on structure and when it was mixed with non-polar and slightly polar solvents, its mobile phase moved the furthest. Such that when Fluorene was put in 25% EtOAc, which is 75% polar, its mobile phase was the furthest, followed by 90% polar in 10% EtOAc in hexane, and its most solid phase was in 100% hexane. 9 – fluorenol is the highest polar compound based on structure and when it was mixed with a polar solvent its mobile phase was the slowest, therefore, it did not travel very far up the silica gel plate. When 9-fluorenol was mixed in slightly polar solvent, 10% EtOAc, its mobile phase also did not travel very far. The only time 9-fluorenol mobile phase travelled up the silica gel plate is when it was combined with