You didn't really show us what you've tried and how it's failing, so about the best we can do is demonstrate some techniques for creating a list of complex numbers given some input list. Here are a few:

use strict;
use warnings;
use feature 'say';
use Math::Complex;

my @array = map {cplx($_->[0], $_->[1])} (
    [1, 8],
    [2, 5],
    [6, 4],
);

say for @array;
[download]

The output will be:

1+8i
2+5i
6+4i
[download]

You could also use List::Util's pairmap:

use strict;
use warnings;
use feature 'say';
use Math::Complex;
use List::Util 'pairmap';

my @array = pairmap {cplx($a, $b)} (1, 8, 2, 5, 6, 4);

say for @array;
[download]

This produces the same output.

Per the documentation for Math::Complex, cplx() is approximately synonymous with Math::Complex->make(), so this would also work:

use strict;
use warnings;
use feature 'say';
use Math::Complex;

my @array;
push @array, Math::Complex->make($_->[0], $_->[1])
    for ([1,8], [2,5], [6,4]);

say for @array;
[download]

And the output will be the same.