Abstract : An solvothermally synthesized acentric 3-D Cd(ii ) metal–organic framework was found to exhibit a unique threefold-interpenetration diamondoid architecture, second-harmonic-generation efficiency, potential ferroelectric property and photoluminescence. Abstract : An excellent one-center-acceptor–donor ligand, 2-aminoisonicotinic acid, was successfully employed to obtain an acentric 3-D metal–organic framework, which exhibits a unique threefold interpenetrated diamondoid network, second-harmonic-generation response, potential ferroelectric behaviors and photoluminescence.