Draw the complete Lewis structure of (CH3)2CHCH(NH2)CO2H and identify all H-bond donors and all H-bond acceptors. Please explain what the parentheses mean.
The Correct Answer and Explanation is:
To draw the complete Lewis structure for (CH₃)₂CHCH(NH₂)CO₂H, let’s break it down:
Step 1: Identify the Components
- (CH₃)₂CH: This is an isopropyl group. It’s composed of two methyl groups (CH₃) attached to a central carbon atom (CH).
- NH₂: This represents an amine group, with nitrogen bonded to two hydrogens.
- CO₂H: This is a carboxyl group, consisting of a carbonyl group (C=O) attached to a hydroxyl group (OH).
Step 2: Assemble the Structure
- The isopropyl group (CH₃)₂CH is attached to the carbon (C) in the NH₂ group.
- The NH₂ group is connected to the carboxyl group (CO₂H).
- The carboxyl group has a carbonyl group (C=O) and a hydroxyl group (-OH).
The structure looks like this:
H2N
|
CH3-CH-CH-COOH
|
CH3
Step 3: Lewis Structure
- The isopropyl group will have single bonds with each CH₃ group attached to the central carbon.
- The amine group (NH₂) has nitrogen single-bonded to two hydrogens.
- The carboxyl group is connected to the central carbon by a single bond, and the carbon is double-bonded to oxygen (C=O). The same carbon is single-bonded to the hydroxyl group (OH).
Step 4: Identify H-bond Donors and Acceptors
- H-bond donors are atoms attached to a hydrogen atom, where the hydrogen is involved in a hydrogen bond. In this molecule, the NH₂ group and the OH group are potential hydrogen bond donors.
- H-bond acceptors are atoms that can accept a hydrogen bond, usually due to their lone pairs. The NH₂ group (because nitrogen has a lone pair), and the O atoms in the CO₂H group are potential hydrogen bond acceptors.
The Parentheses
The parentheses (CH₃)₂ around the methyl groups indicate that the two CH₃ groups are both attached to the same carbon atom in the isopropyl group. This notation avoids writing the full structure repeatedly and simplifies the chemical representation.
