Most of the time I don't split infinitives, but I see nothing inherently wrong with it, especially if doing so contributes to meaning.
In some contexts, splitting the infinitive with 'not' changes the meaning. Consider these two versions of a sentence:
- His instructions were not to give her the information.
- His instructions were to not give her the information.
Sentence 1 means this:
- His instructions were not this: "Give her the information."
Basically, here the word 'not' negates the verb 'be'.
In other words, he received instructions, but they were not "Give her the information". They were different. Maybe his instructions were very different, OR maybe his instructions were only a little bit different. For example: "Send her the information."
.
Sentence 2 means this:
- His instructions were this: "Don't give her the information."
Basically, here the word 'not' negates the verb 'give'.
So, whether or not you split the infinitive with 'not' may sometimes depend on what the intended meaning is.
for more explanation please take look on the links below in order:
1.Link1
2.Link2