split string without a separator

How can I split a string without using a seperator?
This causes an Index is out of range error.

stringVar.Split(""[0]);

Strings are just Char arrays

string s = "abcdefghij";

		string part1 = "";
		string part2 = "";

		for (int i = 0; i < s.Length; i++) 
		{
			if(i % 2 == 0)
			{
				part1 += s*.ToString();*
  •  	}*
    
  •  	else*
    
  •  	{*
    

_ part2 += s*.ToString();_
_
}_
_
}*_

* Debug.Log(part1);*
* Debug.Log(part2);*
Output:
acegi
bdfhj