Four novel cadmium-btx (btx = 1,4-bis(triazol-1-ylmethyl)benzene) coordination polymers [Cd(btx)(2)(NO(3))(2)](n)(1), [Cd(btx)(2)Cl(2)](n)(2), [Cd(btx)(SO(4))(H(2)O)(2)](n)(3), and [Cd(btx)(S(2)O(7))(H(2)O)](n)(4) have been prepared by hydrothermal reaction (140 or 180 degrees C) and characterized. Both 1 and 2 have two-dimensional rhombohedral grid structures, 3 possesses a two-dimensional rectangular grid structure, and 4 displays a three-dimensional framework, which is formed by btx bridging parallel layers. To the author's best knowledge, polymer 4 is the first Cd(II) polymer in which the Cd(II) ion is eight-coordinated in a hexagonal bipyrimidal geometry. In addition, we studied the effects of temperature on the hydrothermal reaction system of btx and CdSO(4) and found that different products can be obtained at different temperatures. Furthermore, polymer 3 possesses a very strong third-order NLO absorptive effect with an alpha(2) value of 1.15 x 10(-)(9) m W(-1). Polymers 2-4 display strong fluorescent emissions in the solid state at room temperature. The DTA and TGA results of the four polymers are in agreement with the crystal structures.

A porous bilayered open coordination polymer [Zn(4,4'-bpy)(2)(FcphSO(3))(2)](n) (1; FcphSO(3)Na=m-ferrocenyl benzenesulfonate), has been assembled from Zn(NO(3))(2), m-ferrocenyl benzenesulfonate, and the bridging ligand 4,4'-bipyridine (4,4'-bpy). Ion-exchange induced products [Cd(0.6)Zn(0.4)(4,4'-bpy)(2)(FcphSO(3))(2)](n) (2), [Zn(0.75)Pb(0.25)(4,4'-bpy)(2)(FcphSO(3))(2)](n) (3), and [Cu(0.5)Zn(0.5)(4,4'-bpy)(2)(FcphSO(3))(2)](n) (4) could be obtained directly by suspending a big single crystal of 1 into concentrated solutions of Cd(NO(3))(2), Pb(NO(3))(2), and Cu(NO(3))(2), respectively. Most importantly, the big single crystal of 1 could be partly regenerated after immersion into concentrated aqueous solutions of Zn(NO(3))(2). On the other hand, powdered 1 could also be used as a metal ion adsorbent because of the well-defined pore size and pore shape. Ion exchange takes place along with the process of ion sorption. The big single crystal of 1 removes harmful metal ions by means of ion exchange, whereas powdered 1 removes toxic metal ions mainly through ion sorption. Also, compound 1 could be employed as a multi-ion analysis fluorescent probe to detect dangerous metal ions, such as Pb(2+), Cd(2+), Ag(+), and Cu(2+). The compounds described in this study may have potential applications in the design of new molecular devices.

Porous pillared bilayer open coordination polymer {[Cd(bpp) 2 (O 3 SFcSO 3 )] • (CH 3 OH) 2 • (H 2 O) 6 } n 1 (Fc ) ferrocene) and 3D porous coordination polymer {[Cd(bpy) 2 (O 3 SFcSO 3 )] • (CH 3 OH) 4 } n 2 have been assembled from Cd(NO 3 ) 2 , ferrocene-1,1′disulfonate, and bridging ligands 1,3-bis(4-pyridyl)propane (bpp) or 4,4′-bipyridine (bpy). Both of them show very special adsorption properties to copper salts. Along with the increase in the solution concentration of Cu(NO 3 ) 2 , the percentage of adsorbed copper ions falls, but the percentage of exchanged central cadmium ions and the amount of adsorbed copper ions rises. In dilute solution, there mainly exists metal ion sorption, whereas both ion sorption and exchange are in charge of the whole progress in strong solution. Meanwhile, such materials could be used as ideal metal ion adsorbent toward some other metal cations, including of Pb 2+ , Zn 2+ , Mn 2+ , Co 2+ , Ni 2+ . However, when all these metal ions coexist in a mixture solution, the two ferrocenyl complexes selectively adsorb large amounts of only Pb 2+ (for 1, 88.54%; for 2, 75.80%) and Cu 2+ (for 1, 90.94%; for 2, 79.45%). Ion sorption and central cadmium ion exchange might be considered as being dominated by the coordination ability of metal ions to free functional groups, ionic radii of adsorbed metal ions, and the solution concentration of adsorbed metal salts. On the basis of the recognition of ion exchange, the center metal ion-exchange product of 2, {[Cd 0.5 Cu 0.5 (bpy) 2 (O 3 SFcSO 3 )] • (CH 3 OH) 4 } n 3, could be obtained by ionexchange-induced single crystal to single crystal transformation.