Constructing porous lanthanide coordination polymers of 4,4'-bipyridine-N,N'-dioxide templated by single- and double-Keggin anions

Three porous coordination polymers, {[Nd(dpdo)(2)(H2O)(5)(CH3OH)(2)](PMo12O40)(CH3OH)-(H2O)(5)}(n) (1), {[Tb(dpdo)(4)(H2O)(3)](PMo12O40)(H2O)(2)CH3CN}(n) (2) and {[Tb(dpdo)(4)(H2O)(3)]H(SiMo12O40)(dpdo)(0.5)(CH3CN)(0.5)(H2O)(4)}(n) (3) (where dpdo is 4,4'-bipyridine-N,N'-dioxide), templated by single- or double-Keggin polyanions were synthesized and characterized by single crystal X-ray diffraction. The compounds exhibit three different 3D non-interwoven frameworks with large cavities occupied by the single- or double-Keggin-type anions. Thermogravimetric analyses suggest different stability for the three metal-organic frameworks. The SHG (second harmonic generation) efficiency of 1 confirms its noncentric framework.