X‐ray and synchrotron diffraction studies of 2‐(pyridin‐2‐yl)‐1, 10‐phenanthroline in the role of ligand for two copper polymorphs or hydrogen bonded with 2, 2, 6, 6‐tetramethyl‐4‐oxopiperidinium hexafluorophosphate. (17th April 2013)