The title compound [Cu2(μ2-dppm)2(MeCN)2(μ2-MeCN)](ClO4)2·MeCN (dppm = bis(diphenylphosphino)methane) has been prepared and characterized. It crystallizes in the monoclinic system,space group P21/n,with a = 11.904(6),b = 20.755(11),c = 24.744(13)A,β = 98.226(12)°,C58H56Cl2Cu2N4O8P4,Mr = 1258.93,V = 6051(5) A^3,Z = 4,Dc = 1.382 g/cm^3,μ = 9.52 mm^-1,F(000) = 2592,R = 0.0533 and wR = 0.1295 for 6175 observed reflections with I 〉 2σ(I). Each Cu(I) center is tetrahedrally coordinated by two phosphine atoms from two bridging dppm ligands,one nitrogen atom from a terminally coordinated acetonitrile molecule,and another nitrogen atom from a μ2-acetonitrile molecule. The two Cu(I) centers are bridged by two dppm ligands as well as a unique acetonitrile molecule. The full molecule exhibits a 'chair-like' configuration. This dinuclear complex exhibits intense or middle photoluminescence at room temperature in the solid state or actonitrile solution at 486 nm.