Magnetic susceptibility of (N H 3 C H 2 C H 2 N H 3 )Cu Cl 4 : A layered structure with strong interlayer magnetic coupling

The magnetic susceptibility of single-crystal (N${\mathrm{H}}_{3}$C${\mathrm{H}}_{2}$C${\mathrm{H}}_{2}$N${\mathrm{H}}_{3}$)Cu${\mathrm{Cl}}_{4}$ has been investigated between 4 and 300\ifmmode^\circ\else\textdegree\fi{}K and this compound was found to be a three dimensional antiferromagnet with a nearest-neighbor exchange of $\frac{J}{k}=23.0\ifmmode\pm\else\textpm\fi{}0.5\ifmmode^\circ\else\textdegree\fi{}$ K and a next-nearest-neighbor exchange of $\frac{{J}^{\ensuremath{'}}}{k}=\ensuremath{-}13.7\ifmmode\pm\else\textpm\fi{}0.5\ifmmode^\circ\else\textdegree\fi{}$ K. The transition to long-range order occurs at 31.5\ifmmode\pm\else\textpm\fi{}0.1\ifmmode^\circ\else\textdegree\fi{}K. The structure of (N${\mathrm{H}}_{3}$C${\mathrm{H}}_{2}$C${\mathrm{H}}_{2}$N${\mathrm{H}}_{3}$)Cu${\mathrm{Cl}}_{4}$ is similar to that of other compounds which exhibit a square-planar nature and comparisons to these compounds are made.