[BloodCrisis]

I was asked to build a emphiric table featuring EWG and EDG of common functional groups , arranging them by its "power". First a table of decreasing Inductive effect; secondly a table of decreasing mesomeric effect and at last a table comparing them and defining "decreasing" Electron Withdrawal Power (electrophylic power). Yes I Know is weird, but this "teacher" is kinda strange; I know that those things are kinda complicated to measure in first place.

The groups to arrange where:

-COOH
-COOR
-NO2
-CONH2
-CN
-SO2OH
-COCR
-COH
-COCl
-OCH3
-COCOCH3
-OH
-F
-Br
-I
-NH2
-F
-H
-CH3

*****

First I started it by considering only inductive effect and ignoring resonance issues.

I couldn´t find any "specific" tables on designated books, so I went to the chaotic world of internet. The thing is that I found two different versions:
Case 1
(From better I- to less I-)
NH3+ > NO2 > CN > SO3H > CHO > CO > COOH > COCl > CONH2 > F > Cl > Br > I > OH > OR > NH2 > C6H5 > H>CH3

Case 2 (Wikipedia)
(From better I- to less I-)
—NR3 > —NO2 > —SO2R > —CN > —COOH > —F > —Cl > —Br > —I > —OR > —COR > —OH > —C6H5 > —CH=CH2 > —H

Well, as you see there are mayor differences between them; so I decided to measure dipole moment (considering, it somehow can give me an indea on "electronegativy" of the group) using a rudimentary molecular simlator; Avogadro.

Case 3
I get this crap:
(From better I- to less I-)
-COOH>-COOR>-NO2>-CONH2>-CN>SO2OH>-COCR>-COH>-COCl>-OCH3>-OH>-F>-Br>-I>-NH2>-F>-H>-CH3

So, I don't really know wich of the three is the right one; of course if there really is a "one".

 I really need to understand how to measure -I effect so I can have a proper table. So

1)Can Anyone help me to do a "groups" generic (-I) table, or knows wich one of the previous is true one?


2)At least if you can, of course; can you arrange first given groups in Decreasing Electron Withdrawal power? (considering both inductive and mesomeric, as a whole, I guess is the standard table)


If you know where i can find dependable tables, can you pass me if you want.

That's all... Thanks for reading

[mjpam]

Do you notice any general patterns I how each list is ordered according to the strength of the inductive effect?

[BloodCrisis]

Obviously my trouble is on the middle of the lists; extremes are quite known.

*Cations go first (NH4+). Those groups which has positive formal charges cause a powerful induction and follows real cations (NO2)
*Hidrogen is the "base" so it has an I+ effect (low electronegativity).
*Alquyl groups are +I
*Because "pi" cloud phenyl group is a weak -I.

*Then is where my problems begins, mainly because two list revised are different....

/-SO2OH/-CN/-COOH/-COOR/ -COONH2/-COOCl/-COH/ -COR / Cl/-OR / -COOCOR / -NH2

So when I get to the carboxylic, carbonyl, halogen and -oxoalquilic groups I mess up.
So amines.

I don't know... they're so alike when you aren't comparing resonance that I cannot deduce the order.

*I guess teacher takes "-R" as a methyl for comparison.

I'm stuck there...

-------------------------

I've been researching and I guess Inductive effects alone are hard to understand; you need high level stuff like Hammer equation; so I suposse I misunderstood the asigment the professor should want me to order the list directly in their EW power; electrphilicity. Even so; i'm kinda confused.

In anyone has a gentle soul and wants to at least organize them by electron withdrawal capacity you'll have my eternal gratefullness (?) xD