Check If IsEmpty, then Insert formula into cell accordingly

I want to check whether a cell in another worksheet is empty and then insert a formula accordingly.

My attempt looks like:

Range("IN47").Select
    If IsEmpty(Worksheets(1).Range("A2").value) = True Then
    Range("IN47").Formula = "=Concatenate('Name 1'!B2; " @ "; 'Name 1'!C2)"
    End If

I get invalid character the error message. If I directly paste the formula into the cell then it works as it should.

What am I doing wrong?