Relative Rates: Free-Radical Bromination

BroIn this experiment of the proportional rates of free- complete chain bromination, we were anticipate to be able to determine the relative activates of the many types of hydrogen atoms involved toward bromine atoms. Bromination is defined to be a regioselective counterbalanceion meaning bromine has preference of making or breaking a bond over all other directions that it may have had available.In this case, Markovnikovs rule is revealed to be the case in this situation that states that adding a protic acid equal as HX to an alkene (sp2 hybridized), the hydrogen from that HX would be attracted to a carbon with the least alkyl groups and the halide (X) would become much attracted and will attach to the carbon containing more alkyl groups. Within the intermediate stage of the bromination reaction, the bromine radical will have already formed and the electronegatively charged radical will have a excerpt of how to protonate in order to create a stable carbocation.In order to det ermine these sp3 hybridized carbons stability, it bottomland be set(p) by knowing that while comparing, if there ar less alkyl groups attached to a carbocation, wherefore there would non be enough electrons to slightly mask over the positive charge on that certain carbocation. Due to this, the more alkyl groups that are attached, the more stable the carbocation would be due to the particular that the electron flow in the electron cloud slightly donates to the carbocation making it almost completely stable.During the experiment, we were expected to organize two groups of tubes with methylene chloride with their respective hydrocarbon (10 drops) as well as the addition of a down in the mouth amount of bromine. One group of tubes was set in the light and one was set in the vestige and when compared, you were already able to see that the ethylbenzene and toluene were the fastest to react in both situations.Due to this fact we can tell since they were the fastest reacting, they c an be associated with the fact that they were more than likely secondary and primary benzylic carbons due to their excellent stability and fast reactions. The only other tube that reacted through observation (by eye) by the end of the experiment was the methylcyclohexane and we could tell that it had slightly reacted by its slight orange color, but was not still completely red like the others(sign of bromine).The next most stable carbocation form would be the ordinal aliphatic carbon, so we will infer that this is what has occurred in this case. Due to the fact that methylcyclohexane is sp3 hybridized, we can pin call for that our assumption that the bromination is tertiary aliphatic because it is stable with there being three alkyl groups present which agent that the electrons within these groups are delocalized and are contained within an orbital that extends over the adjacent atoms involved. The last two tubes to react within the group were cyclohexane and t-butylbenzene in th at order.When first added the bromine, these two were the only ones that seemed to remain red longer and remained the same shade of red even after all of the other tubes had reacted. The reaction of cyclohexane however was expected to react slightly more than the t-butylbenzene due to the fact that the positive charge on the carbocation is delocalized better when there are more alkyl groups involved. This will match up the two with secondary (cyclohexane) and primary aliphatic (t-butylbenzene) bromination.