  Monoclinic CuO is anomalous both structurally as well as electronically in
the 3$d$ transition metal oxide series. All the others have the cubic rock salt
structure. Here we report the synthesis and electronic property determination
of a tetragonal (elongated rock salt) form of CuO created using an epitaxial
thin film deposition approach. In situ photoelectron spectroscopy suggests an
enhanced charge transfer gap $\Delta$ with the overall bonding more ionic. As
an end member of the 3d transition monoxides, its magnetic properties should be
that of a high $T_N$ antiferromagnet.
