RelatedTo "and" and arrays I have something I can not get my head around.

This works as expected:

.relatedTo(['and',{targetElement:22},{targetElement:33}])


But when I am building an array to use as relation criteria like so:

{% set related = [{targetElement:22},{targetElement:33}] %}

.relatedTo(['and',related])


Nothing returns.

It’s pretty late here in Berlin and I might be missing something simple but can not see what exactly. Anyone?
I don’t know what it is – I swear: every time – but the next thing I tried, immediately after posting the question was this:

{% set related = ['and',] %}
{% for relation in relations %}
    {% set related = related|merge([{targetElement:relation}]) %}
{% endfor %}

{% paginate craft.entries
    .section('documents')
    .relatedTo(related)
    as entries %}   


That works.