Natural Number makes a difference

Since we know that $i=e^{i\pi/2}$ , which of the following is correct one?

$\large 1. i^i=e^{(i)(i)\pi/2}=e^{-\pi/2}$

$\large 2. i^i =i^{(-1)^{1/2}}=(-i)^{1/2}= \frac{\sqrt{2}}{2} ( -1 + i )$