Mix-Solvothermal Syntheses, Characterization, and Properties of New Zinc Diphosphonates with Zn−O−P Chains, Layers, and 3D Frameworks

Eight new zinc diphosphonates, [NaZn(O3P(CH2)2PO3H)] (1), [K2Zn2(HO3P(CH2)2PO3H)(O3P(CH2)2PO3)] (2), [(NH4)(H3N(CH2)2NH3)0.5Zn3(O3P(CH2)2PO3)2] (3), [(NH4)2Zn3(O3P(CH2)3PO3)2] (4), [(H3N(CH2)4NH3)0.5Zn(O3P(CH2)3PO3H)] (5), [KZn(O3P(CH2)4PO3H)] (6), [KZn(HO3P(CH2)4PO3H)(Cl)] (7), and [NH4Zn(O3P(CH2)4PO3H)] (8), have been successfully synthesized
under mixed solvothermal conditions and characterized by X-ray single-crystal diffraction together with elemental analysis, infrared
spectroscopy, thermogravimetric analysis, and powder X-ray diffraction. In 1 and 2, 1,2-ethylenediphosphonate groups combine
cations (Na+, K+) and Zn−O−P layers into 3D frameworks, while in 3 and 4, ethylene and propylene groups are enclosed in novel
3D Zn−O−P frameworks, respectively, which possess 8-membered ring (8MR) and 12MR channels. In 5−8, Zn−O−P infinite
chains are pillared by 1,3-propylene- and 1,4-butylenediphosphonate groups into hybrid layers. It is interesting that in 7 K−Cl
lamellae link the Zn−O−P hybrid layer to form a 3D sandwichlike framework. If 1 is synthesized with commercial fluorescent
whitener (disodium 4,4‘-bis(2-sulfonatostyryl)biphenyl) in the initial reaction mixture, it exhibits bright purple-blue luminescence
with a short lifetime. Photoluminescent properties of 4 and 8 are also discussed.