Four new inorganic–organic hybrid frameworks [Mn(L)(H 2 O) 2 ] n (1), {[Co(L)(H 2 O) 3 ]·2H 2 O·CH 3 OH} n (2), {[Zn(L)(H 2 O)]·H 2 O} n (3) and [Cd(HL) 2 ] n (4) [H 2 L=4-(isonicotinamido)phthalic acid] have been synthesized and characterized by single-crystal X-ray diffraction analysis. Complex 1 has three-dimensional (3D) structure and topology related to SrAl 2 (sra) with Schläfli symbol of (4 2 ·6 3 ·8). And 2 displays (3,3)-connected two-dimensional (2D) network with (4,8 2 ) topology, while 3 exhibits a uninodal (3,3)-connected (6,3) 2D network, which is further linked by N–H⋯O hydrogen bonding interactions to give 3D structure with hms topology and Schläfli symbol of (6 3 )(6 9 ·8). Complex 4 with partial deprotonated HL − ligands also has a 2D network structure. In addition, the magnetic property of 1, nonlinear optical property of 3 and photoluminescence of 3 and 4 were investigated.