Synthesis, Crystal Structures And Properties Of Transition Metal Phosphonates

Seven novel transition metal phosphonates have been hydrothermally synthesized by employing2-hydroxyphosphonoacetic acid (H2O3PCH(OH)CO2H),4-HOOCC6H4CH2NHCH2PO3H2, and1-hydroxyethylidenediphosphonic acid (H4hedp) as the phosphonate ligand. All above compounds were characterized by X-ray powder diffraction, X-ray single-crystal diffraction, thermogravimetric analysis and IR spectroscopy. The luminescent properties of compounds1and4have been studied. The molecular recognition properties of compound4in alkyl alcohol emulsions have been studied. The dehydration/hydration properties of compound2have been also studied. Surface photovoltage properties of the compounds2,3,5,6and7have been investigated. The chemical constitution formulas of the seven kinds of compounds were listed as follows:(1)[pzH2]0.5[Cd(HO3PCH(OH)CO2)Cl]·2H2O (2)[Mn(HO3PCH(OH)CO2)]H2O (3) Co[O3PCH2NH2CH2C6H4COO]·H2O (4) Cd3[(O3PCH2NCH2C6H4COO)2(H2O)3](5) Mn[O3PCH2NH2CH2C6H4COO](6) Fe[O3PCH2NH2CH2C6H4COO](7)[{Cu(2,2’-bipy)(H20)}(Mo0.5O)(H2hedp)]·6H2OCompounds1and2have been synthesized by employing2-hydroxyphosphonoacetic acid (H203PCH(OH)CO2H) as the carboxyphosphonates ligand. Compound1feature two-dimensional (2D) inorganic layers. Compound2features a3D framework structures. By employing4-HOOCC6H4CH2NHCH2PO3H2as the phosphonate ligand, our research efforts resulted in four novel metal carboxyphosphonates compounds (3-6) with a3D pillared-layered structure. Compound7have been synthesized by employing1-hydroxyethylidenediphosphonic acid (H4Hedp) as the carboxyphosphonates ligand. The π-π stacking interactions make compound7form a1D supramolecular structure. TG curve indicates that compounds1-6have better thermostability. The investigation of luminescent properties indicates that compound1and4may be good blue-light luminescent materials. We explore the potential of compound4for the sensing of alkyl alcohol by luminescent method. The luminescent intensity of compound4emulsions gradually increased with the addition of methanol, ethanol,1-propanol solvent. While we improved the content of1-butanol solvent in the emulsion of compound4, the luminescent intensity was evidence quenched. The luminescent intensity of compound4emulsion didn’t show significant changes by the addition of1-pentanol solvent. Such behavior indicates compound4could be potentially used for the sensing of methanol, ethanol,1-propanol,1-butanol. This is the first example of the studies on the molecular recognition property of transition metal phosphonate materials, which need to be further studied. The dehydration/hydration experiment reveals that compound3possess excellent dehydration/hydration properties. Furthermore, the SPS and FISPS of compounds2,3,5,6and7indicate that they exhibit surface photovoltage properties and showp-type semiconductor characteristic.