N-Butane Conformation Stability
Conformational analysis examines the relative energies of different spatial arrangements (conformations) of a molecule that arise from rotation around single bonds. For n-butane ($CH_3CH_2CH_2CH_3$), the rotation around the central C2-C3 bond leads to various conformations.
Energy Factors in N-Butane Conformations
The stability of these conformations depends on:
- Torsional Strain: Energy cost due to eclipsing electron densities of bonds.
- Steric Strain (or Van der Waals Strain): Repulsive interactions between non-bonded atoms or groups that are close to each other in space.
Analysis of N-Butane Conformations
The key conformations and their relative stability are:
- Fully Eclipsed (0°): Highest energy due to maximum steric strain (methyl groups eclipsed) and torsional strain.
- Gauche (approx. 60°): Lower energy than eclipsed forms. There is some steric strain between the two methyl groups, but less than in the fully eclipsed form.
- Eclipsed (approx. 120°): Higher energy than gauche due to torsional strain and some eclipsing interactions between H and $CH_3$.
- Anti (approx. 180°): Lowest energy conformation. The two methyl groups are positioned 180° apart, minimizing steric hindrance. Torsional strain is also minimized compared to eclipsed forms.
Conclusion on Stability
The Anti form is the most stable conformation of n-butane because it minimizes both torsional strain and, crucially, the steric repulsion between the bulky methyl groups.
Similar Questions
- Match the LIST-I with LIST-II
LIST-I Complex LIST-II Metal A. Haemoglobin I. Co B. Chlorophyll II. Fe C. Vitamin B$_{12}$ III. Pt D. Cis platin IV. Mg
Choose the correct answer from the options given below: - Non-stoichiometric KCl exhibits a blue lilac colour because of -
- Match the LIST-I with LIST-II
LIST-I Ligand LIST-II denticity A. Pyridine I. 3 B. DMG II. 6 C. EDTA III. 2 D. Dien IV. 1
Choose the correct answer from the options given below: - When alkali metal are dissolved in liquid ammonia the blue colour of solution is due to
- Which of the following is the cause of photochemical smog?
- Environmentalist use which of following compound as bleaching agent
- Which of the following group attached to benzene act as meta directing group
- Which of the following reaction intermediate can not show sp$^2$ hybridisation
- Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: The characteristic feature of the endosperm haustoria is that they are developed from the cellular endosperm only
Reason R: The endosperm haustoria are formed at the micropylar or chalazal or at both the ends and penetrate the nucellar tissue to absorb nutrition.
In the light of the above statements, choose the most appropriate answer from the options given below - Cleavage polyembryony is fairly common in
Important Questions from Mixed Topic (CUET PG)
- Who was the founder of Bolshevik Communist party?
- What is the key guide to statecraft in the realist tradition?
- Chronologically arrange the events in the Cold War period.
A. Berlin Wall is constructed
B. Communist China joins the UN
C. Soviet invasion of Czechoslovakia
D. Berlin Blockade
Choose the correct answer from the options given below: Morgenthau's principles of political realism are:
A. Politics is rooted in permanent and unchanging human nature which is basically self centred, self-regarding and self-interested
B. Politics is an autonomous sphere of action and cannot therefore be reduced to morals
C. International Politics is an arena of conflicting self-interests
D. The ethics of international relations is situational ethics which is very different from private morality
Choose the correct answer from the options given below:Who among the following political thinkers consider the anarchical self help system to be a compelling factor for States to maximise their relative power positions?
