Hide PDF's from Right-Split view

Is it possible to hide the PDF column in right-split view in the endnote (X7) Library (Mac)? I thought I once knew the answer, but no longer do. thx

You could either: 1) change the Layout to “Right” which will make the Reference window the default (or you could change the default to Preview); or 2) drag the left-edge border of the PDF window all the way to the right.