What is the difference between NをNとする and NをNとして/に?


I am very confused about とする vs. として/に. I am working on the Try book for N2
and in one of the practices it's asking to pick between とする, として, and に in
example sentences.

> 企業は利益を上げることを目的(として/とする),日々、経済活動を行っている。




Simply, ～とする is adjectival (modifies a _noun_ as a relative clause), and ～として
is adverbial (modifies a _verb_ as a te-form).

The next _noun_ after the modifier in question is 日々. It's a noun that also
works as an adverb, just like 明日, 去年, 今月, etc. If you say 利益を上げることを目的と **する**
, it looks like it modifies 日々, and the whole sentence would look like
"Companies conduct economic activities in the profit-pursuing days", which
makes little sense because there is no such a thing as "non-profit-pursuing
days" of a company. Instead, this modifier must modify the next _verb_ ,
(経済活動を)行う.

> 企業は利益を上げることを目的として日々経済活動を行っている。  
>  Companies conduct economic activities every day with the purpose of making
> a profit.

In the English translation, you can see "with the purpose of making a profit"
is modifying not "every day" but "conduct economic activities".

AをBに is also adverbial. It's perfectly fine to say
企業は利益を上げることを目的に日々経済活動を行っている, too.

* * *

By the way, What if there is no 日々?

>   1. 企業は利益を上げることを目的として経済活動を行っている。
>   2. 企業は利益を上げることを目的とする経済活動を行っている。
>

Both are grammatical, but still, the former is more natural. In Sentence 1,
経済活動を行っている is adverbially modified by 利益を上げることを目的として ("Why companies do
economic activities? Because they want to make a profit!"). This makes sense.
In Sentence 2, 経済活動 is adjectivally modified by 利益を上げることを目的とする ("What kind of
economic activity? The one that can make a profit!"). This sounds odd because
it sounds as if there were such a thing as "non-profit-pursuing economic
activity".

