20208-95-1Relevant articles and documents
Tris(2,4,6-triamino-1,3,5-triazin-1-ium) Dihydrogenphosphate Monohydrogenphosphate Tetrahydrate
Hausner, Josef,Butterhof, Christian,Martin, Thomas,Milius, Wolfgang,Breu, Josef
, p. 2871 - 2875 (2014)
When "recrystallizing" the commercial flame retardant melaminium orthophosphate, surprisingly a hydrate with a diverging stoichiometry of melaminium (M) and phosphate (P) was obtained (M3P2 ·4H2O). The structure of M3P2 ·4H2O was solved by single-crystal X-ray diffraction analysis. The arrangement of positive melaminium and negative phosphate layers found in the crystal structure allows for both electrostatic attraction and hydrogen bonding networks. The melaminium layers are comprised of hydrogen-bonded ribbons of melaminium, which in turn are connected by π-π interactions into layers. The negatively charged phosphate layers are comprised of hydrogen bonded dihydrogenphosphate dimers and hydrogenphosphate dimers, which in turn are interconnected by direct and water-mediated hydrogen bonding into layers.
Melamine-based functionalized graphene oxide and zirconium phosphate for high performance removal of mercury and lead ions from water
Awad, Fathi S.,Bakry, Ayyob M.,Bobb, Julian A.,El-Shall, M. Samy,Ibrahim, Amr A.
, p. 37883 - 37897 (2020)
Heavy metal ions are highly toxic and widely spread as environmental pollutants. This work reports the development of two novel chelating adsorbents, based on the chemical modifications of graphene oxide and zirconium phosphate by functionalization with melamine-based chelating ligands for the effective and selective extraction of Hg(ii) and Pb(ii) from contaminated water sources. The first adsorbent melamine, thiourea-partially reduced graphene oxide (MT-PRGO) combines the heavier donor atom sulfur with the amine and triazine nitrogen's functional groups attached to the partially reduced GO nanosheets to effectively capture Hg(ii) ions from water. The MT-PRGO adsorbent shows high efficiency for the extraction of Hg(ii) with a capacity of 651 mg g-1 and very fast kinetics resulting in a 100% removal of Hg(ii) from 500 ppb and 50 ppm concentrations in 15 second and 30 min, respectively. The second adsorbent, melamine zirconium phosphate (M-ZrP), is designed to combine the amine and triazine nitrogen's functional groups of melamine with the hydroxyl active sites of zirconium phosphate to effectively capture Pb(ii) ions from water. The M-ZrP adsorbent shows exceptionally high adsorption affinity for Pb(ii) with a capacity of 681 mg g-1 and 1000 mg g-1 using an adsorbent dose of 1 g L-1 and 2 g L-1, respectively. The high adsorption capacity is also coupled with fast kinetics where the equilibrium time required for the 100% removal of Pb(ii) from 1 ppm, 100 ppm and 1000 ppm concentrations is 40 seconds, 5 min and 30 min, respectively using an adsorbent dose of 1 g L-1. In a mixture of six heavy metal ions at a concentration of 10 ppm, the removal efficiency is 100% for Pb(ii), 99% for Hg(ii), Cd(ii) and Zn(ii), 94% for Cu(ii), and 90% for Ni(ii) while at a higher concentration of 250 ppm the removal efficiency for Pb(ii) is 95% compared to 23% for Hg(ii) and less than 10% for the other ions. Because of the fast adsorption kinetics, high removal capacity, excellent regeneration, stability and reusability, the MT-PRGO and M-ZrP are proposed as top performing remediation adsorbents for the solid phase extraction of Hg(ii) and Pb(ii), respectively from contaminated water. This journal is
Synthesis, characterization and thermal behavior of tetrakis(melamine2+) bis(melamine+) pentakis(monohydrogenphosphate) tetrahydrate
Youcef, Hakima Ait,Chafaa, Salah,Doufnoune, Rachida,Douadi, Tahar
, p. 138 - 143 (2016/07/06)
A new organic-inorganic salt, tetrakis (2,4,6-Triamino-1,3,5-Triazin-1,3-diium) bis (2,4,6-Triamino-1,3,5-Triazin-1-ium) pentakis (monohydrogenphosphate) tetrahydrate, 4C3H8N6+2. 2C3H7N6+. 5HPO42-. 4H2O was synthesized through the reaction of melamine and phosphoric acid in an acidic medium HCl/H2O. It was then characterized by X-ray diffraction. The title compound crystallizes in monoclinic system with non-centrosymetric space group P 21 with lattice parameters a = 11.3008 ?, b = 20.9798 ?, c = 12.2679 ?, α = 90°, β = 117.236°, γ = 90°, Z = 2 and V = 2586.10 (?)3. The UV-vis absorption spectrum UV-vis showed that the crystal has a good optical transmittance in the entire visible region with a lower cut off wavelength of 290 nm. The vibrational frequencies of various functional groups present in the crystal were identified by FT-IR analysis. The chemical structure of the compound was also confirmed by 1H, 13C and 31P NMR spectroscopy. TGA-DTA analysis revealed that the materials have a good thermal stability without any melting.
