7. Given the complex number $z=a+\mathrm{i}(a \in \mathbf{R})$ corresponds to a point in the second quadrant in the complex plane, and $|z(1+\mathrm{i})|>2$. Then the range of the real number $a$ is $\qquad$

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$$
\text { II, 7. } a2 \\
\Rightarrow 2 a^{2}+2>4 \Rightarrow a1 .
\end{array}
$$

Therefore, $a<-1$.