Which of the following best represents the structure of 1,4-hexanediamine?

• A. $H2N–\mathrm{CH}2–\mathrm{CH}2–\mathrm{CH}2–\mathrm{CH}2–\mathrm{CH}2–\mathrm{NH}2$
• B. $H2N–\mathrm{CH}2–\mathrm{CH}2–\mathrm{CH}2–\mathrm{CH}2–\mathrm{NH}2$
• C. $H2N–\mathrm{CH}2–\mathrm{CH}2–\mathrm{NH}2$
• D. $H2N–\mathrm{CH}2–\mathrm{CH}2–\mathrm{CH}2–\mathrm{NH}2$

Answer: (B)

Verified step by step guidance

1. Identify the parent carbon chain length from the name 1,4-hexanediamine. The prefix 'hex' indicates a six-carbon chain.
2. Recognize that 'diamines' means there are two amine (-NH2) groups attached to the carbon chain.
3. Locate the positions of the amine groups on the carbon chain. The numbers 1 and 4 indicate that the -NH2 groups are attached to the first and fourth carbons.
4. Draw a straight chain of six carbon atoms: \(\mathrm{CH_3-CH_2-CH_2-CH_2-CH_2-CH_3}\), then replace the hydrogens on carbons 1 and 4 with amine groups, resulting in \(\mathrm{H_2N-CH_2-CH_2-CH_2-CH_2-CH_2-NH_2}\).
5. Verify that the structure matches the name by counting carbons and ensuring the amine groups are correctly positioned at carbons 1 and 4.