Coordination Polymers, Crystal Engineering, Lanthanide, Mangetic A total of twelve new metal-organic coordination polymers were synthesized and characterized. Slow diffusion reactions at room temperature of metal chloride, ferric chloride, and two-connecting organodinitrile ligands in 1:2:3 ratio using nitromethane afforded [Fe(pdn)](FeCl4)2 (KCTRF1), [Fe(pdn)(H2O)](FeCl4)2 (KCTRF2), [Fe(hdn)](FeCl4)2 (KCTRF3), [Fe(adn)](FeCl4)2 (KCTRF4), and [Co(adn)](FeCl4)2 (KCTRF5), where pdn = p-phthalodinitrile, hdn = trans-3-hexenedinitrile, adn = adiponitrile. Compound KCTRF1 has a 3D framework cationic host framework of [Fe(pdn)3]2+ which is charged balance by two a distorted tetrahedral “guest” [FeCl4]− anions, and exhibits interesting half spin crossover. Compounds KCTRF2-KCTRF5 has a 2D layer structure, and all are in paramagnetic species. Three new cyanidebridged bimetallic compounds, KCTRF6, KCTRF7 and KCTRF8 were obtained by the using the [Ru(CN)6]2– or [Ag(CN)2]– donor building block. Compound KCTRF6 possesses a 1D neutral chain structure. Compound KCTRF7 has a neutral 3D heterometallic cyanide framework, and is antiferromagnetic behavior. While, compound KCTRF8 has a neutral 3D quartz-like framework. Using same stoichiometry and hydrothermal method, a beautiful series of a 3D samarium(III) framework containing mixed fumarate and terephatlate ligands, KCTRF9-KCTRF12, were isolated with different temperatures.