The expression is missing critical details. Could you clarify or provide the full expression? For example:

• Is the negative sign applied to a radical, such as $-\sqrt{23}$?
• Is the problem requesting the use of $i = \sqrt{-1}$ to convert a radical involving a negative number?

If the expression is $-\sqrt{23}$, it cannot involve $i$ because $-\sqrt{23}$ is already a real number. However, if the expression is something like $\sqrt{-23}$, it can be rewritten using $i$.

Let me know the specific details so I can assist further!