Place every n-th character in string at n-7 position

I have string with 0's and 1's. It looks like this:

1110011011010000...

With spaces for better visualisation (original string from my program doesn't contain spaces)

11100110 11010000 ...

Every eight elements must be a letter of Unicode in binary.

What i need to do, is put every last 0 or 1 of each letter (every 8th element in full string) to the first place for this letter, so this string would be like this:

0111001101101000...

With spaces for better visualisation (original string from my program doesn't contain spaces)

01110011 01101000 ...

How can I do this in C#?