1. No. SN2 has a penta-coordinate transition state where the incoming nucleophile is making a bond and the leaving group is breaking its bond. The only charge you get here is a polarized bond which is caused by the leaving group pulling away from its carbon, leaving a partial positive on the carbon the incoming nucleophile is attacking.
2. It all depends on how you define these two I would think. A transition state actually does not really have a "time" associated with it. It is never there for a long enough time actually to see it. When you talk about intermediates, you usually think of stuff like "bromonium ions (bromine bridge), or an epoxide intermediate. An intermediate is usually the steps in between the starting material and final product. An epoxide or oxirane is actually a structure that is not a transition state. These two terms sort of go hand in hand as well if you think about it. You usually say, the "transition state intermediate", meaning that the reaction does not sit like that but will go on to form product from this structure.
3. Anti-Mark and Mark just have to do with addition across double or triple bonds. Lets say you have CH3CH=CH2 reacing with HBR. The H will add across the primary carbon of the molecule, leaving the carbocation on the 2 prime or most stable. Then Br- attacks the carbocation. An example of ANTI-MARK is HBR w/ ROOR. This adds the BR to the least stable part of the double bond, placing a dot in the most stable and then H will attack the dot. Also, a double bond reacting with 1. BH3/THF followed by 2. HOOH/OH- is also considered an ANTI-MARK addition. The speed of something reacting and forming a carbocation etc, actually has to do with 1,2 or 1,4 addition and thermodynamic and kinetic controls.
3. I would think internal alkenes and alkynes have higher BP because they are more stable molecules due to inductive effects. ie. CH3CH=CH-CH3. The middle carbons are sp2 hybridized and the outside methyl's are sp3. There is actually a slight dipole here pointing towards the lower energy state sp2 carbons because they are lower in energy and can be considered theoretically as more EN because the e-density of the methyl's will tend to be closer to the sp2 carbon and not the sp3 carbon. Here you have two methyl groups donating e-density towards a lower energy state. As with, CH3CH=CH2, now you only have one methly donating e- density towards that sp2 carbon so this is actually a higher energy molecule and will boil and lower temperatures. Same goes for alkynes.
4. NO2 off a benzene ring is deactivating and meta-directing because the N actually has a full positive charge. If you do out the resonance structures, attacking para or ortho will place the positive charge next to the full + on the N which is bad. Attacking meta will delocalize the + charge so that it never sits on the carbon next to the Nitrogen.
5. The reason for this is because CH3 off benzene=toluene and is activating and para/ortho directing. Now, there is two ortho sites and one para site, so thats where the percentages come into play.
6. Absolutely not. E1 will only occur when you have a strong acid such as H2SO4 or H3PO4 reacting with an alcohol. That is the ONLY time you get an E1 reaction. You can get SN1 with a weak base such as ethanol reacting with a molecule that has a leaving group or you react acids like HBR, HCL with alcohols. These are all SN1 mechanisms that go through a carbocation intermediate. E1 also goes through a carbocation intermediate but the incoming nucleophile sucks so therefore instead of substituting, you get H abstraction from H's located next to the carbocation.
Hope this helps.
1. can SN2 ever make a carbocation? is it ever possible?
2. What is an exact difference between a "Transition State" and and "intermediate"?
2. so I undrestand that the speed of addition between Cl and Br are different and Br adds alot faster than Cl... But what difference does that make on Markov and Anti markov or does it??
3. Why do internal alkenes or alkynes boil at a higher temp?? (is it because of delocalization)
4. is NO3 an activator or deactivator??
5. In Kaplan it states that on a "Toulene".... a "NO2" adds 63% on the ortho side and 34% on the para side. Why is that??
6. is heat the only way to tell the diff between E1 and SN1??
Thank you guys
