I want to define a range in my workbook, and can't figure out what's wrong with my syntax. Can I get some help? 

Worksheets("Lookups").Range(Columns(5),(ActiveCell, ActiveCell.End(xlDown)).Name = "PertPacs1"
Excel is saying this is invalid syntax (the bane of my existence!) but I don't understand why. I want to name the range of visible cells in column F of my Lookups worksheet. Any help is greatly appreciated.