5 Multiple Answer 2 points Which of the following is not a nucleophile? \( \begin{array}{llll}\text { A) } \mathrm{H}_{2} \mathrm{O} & \text { B) } \mathrm{NH}_{3} & \text { C) CO } & \text { D) } \mathrm{BH}_{3}\end{array} \) E) \( \mathrm{H}_{2} \mathrm{~S} \) \( \begin{array}{l}\text { A } \\ \text { C } \\ \text { C } \\ \text { E } \\ \text { Previous }\end{array} \)

When we talk about nucleophiles, we're referring to species that can donate an electron pair to form a chemical bond. Interestingly, borane (BH₃) is not a typical nucleophile; rather, it acts as a Lewis acid because it can accept electron pairs rather than donate them. This characteristic makes BH₃ unique when compared to the other options, which are all capable of donating electron pairs. For a better understanding of nucleophiles, consider the classic reaction between ammonia (NH₃) and carbonyl compounds. In this reaction, NH₃ acts as a nucleophile, attacking the electrophilic carbon of the carbonyl, ultimately leading to the formation of an amine. This real-world application showcases the importance of recognizing nucleophilic behavior in organic reactions!