A new salt, NO sub(2)BzDMAP sub(3)Cu sub(2)Cl sub(7) . H sub(2)O (1), has been synthesized, where NO sub(2)BzDMAP super(+) is 1-(4'-nitrobenzyl)-4-dimethylaminopyridinium. Herein, the synthesis, spectral and structural characterization, and magnetic behavior of 1 are reported. It is orthorhombic, with space group Pca2 sub(1), and a = 26.639(2) Aa, b = 9.638(1) Aa, and c = 20.011(2) Aa with V = 5137.5(7) Aa super(3) for Z = 4. The anion shows a chloride-bridged binuclear structure with Cu ... Cu distance of 3.872 Aa; the two Cu(II) ions have a tetrahedral geometry. The cations stack through p ... pi and pi ... pi interactions, and a complicated hydrogen-bonding network structure is formed through C-H ... Cl and C-H ... O hydrogen bonds. The variable temperature magnetic susceptibility measurements reveal that 1 exhibits strong antiferromagnetic interaction with J = -193.0 cm super(-1).