Chemistry Which Group Exhibits a Stronger Inductive Effect, Sec-Butyl or Propyl?

[Physics lover]

Homework Statement

Which has more +I effect Propyl or Sec butyl

Relevant Equations

Inductive effect
Difference in electronegativity
Distance dependent

I am confused.If i think in terms of distance than propyl group in sec butyl is far away than in normal propyl.But if think in no. of Carbon atoms then sec butyl should have more +I effect as it is has more Carbon atoms.
Tell me which is the correct one?

 

[epenguin]

Homework Statement: Which has more +I effect Propyl or Sec butyl
Homework Equations: Inductive effect
Difference in electronegativity
Distance dependent

I am confused.If i think in terms of distance than propyl group in sec butyl is far away than in normal propyl.But if think in no. of Carbon atoms then sec butyl should have more +I effect as it is has more Carbon atoms.
Tell me which is the correct one?

Your second sentence practically does not mean anything that I can understand. Distance of what from what?

Don't think so much about rules as mechanisms – what is the mechanism of the inductive effect? Then look at the structures and see what that seems to imply.

 

[Physics lover]

i

Your second sentence practically does not mean anything that I can understand. Distance of what from what?

Don't think so much about rules as mechanisms – what is the mechanism of the inductive effect? Then look at the structures and see what that seems to imply.

think sec butyl has more inductive effect as there is 1 more ch3 group in it than n propyl.So am i Correct?

 

[epenguin]

i

think sec butyl has more inductive effect as there is 1 more ch3 group in it than n propyl.So am i Correct?

Maybe, but not precise enough to convince a sceptical examiner completely. 2-methylpropan-1-ol ("isobutanol") also has one more -CH3 group than propan-1-ol ( using the proper names is also more helpful and convincing) - does that have a greater inductive effect?
You need to briefly invoke and specify the physical mechanism of the inductive effect, not just rules and names.

 

[Physics lover]

Maybe, but not precise enough to convince a sceptical examiner completely. 2-methylpropan-1-ol ("isobutanol") also has one more -CH3 group than propan-1-ol ( using the proper names is also more helpful and convincing) - does that have a greater inductive effect?
You need to briefly invoke and specify the physical mechanism of the inductive effect, not just rules and names.

ok as we know inductive effect occurs due to difference in electronegativity of atoms.In this case the terminal carbon atom in sec butyl would be more electronegative than that in n propyl as it will have more partial negative charge on terminal carbon due to presence of 1 more ch3 group than n propyl.Therefore sec butyl should be weaker +i group than n propyl.Am i correct now?

 

[epenguin]

I don't think so, but even if you are it is not doing you much good because of the lack of clarity with which you express it.
I.e. wouldn't do you much good for grades or examinations. As one Prof said to me, is the student is on top of the question it hits you in the face as soon as you see his answer.

With other answers he might be saying to himself yes, no, maybe.If you are lucky enough that you can have some interaction with him he might try to ascertain or to hint or remind you or set you thinking by asking a further question.If then you don't reply to that what is he going to conclude? He'll put that down as a No.

In your answer it will also help clarity if you can use the systematic terminology that I am using in #5.You may not have learned this yet, but the examples are sufficient for all you need to this problem.Then each atom has a number and you can state which atom you are referring to C1, C4 or what.