Crystal structure of magnesium(II) diaquatetracarbamidenitrate

Abstract

416Numerous magnesium complexes with carbamide, formamide, acetamide, and dimethylcarbamide have been studied in a detailed way. The structural variety of magnesium(II) complexes with carbamide type ligands prepared from water-organic systems may be reduced to a few species that are conventionally described as [Mg(H 2 O) 2 (ur) 4 ] 2+ [1] and [Mg(ur) 6 ] 2+ [2-5]. We have also described a compound which con tains both [Mg(ur) 6 ] 2+ and [Mg(H 2 O) 4 (ur) 2 ] 2+ cations [6], where the apical arrangement of the carbamide type ligand is characteristic of the latter. The complex [Mg(H 2 O)(L)(ur) 4 ] (L = ) has the most interest ing configuration of the inner coordination sphere [7], where water molecules and the bulky sulfato group are positioned nonapically.This study deals with the crystal structure of the magnesium nitrate complex with carbamide, Mg(NO 3 ) 2 ⋅ 4CO(NH 2 ) 2 ⋅ 2H 2 O, which is produced by reacting magnesium nitrate and carbamide in aqueous media. EXPERIMENTALSingle crystals of Mg(NO 3 ) 2 ⋅ 4CO(NH 2 ) 2 ⋅ 2H 2 O were synthesized using magnesium nitrate hexahy drate (chemically pure grade) and carbamide (pure for analysis grade). For the reason that the complex is congruently soluble in water, the reagents were taken in a stoichiometric proportion (Mg(NO 3 ) 2 : CO(NH 2 ) 2 = 1 : 4) and dissolved in water at 50°С. The resulting aqueous solution was slowly concentrated at room temperature. Separated crystals of the complex were identified by chemical analysis, differential thermal analysis, and IR spectroscopy. SO 2 4 − X ray crystallography. An experimental data set for complex I was collected on a Bruker SMART APEX2 CCD diffractometer at 293 K(MoK α radiation) from a single crystal 0.30 × 0.20 × 0.15 mm. An absorption correction was applied using APEX2 software [8]. The Abstract-Magnesium(II) diaquatetracarbamidenitrate nitrate was structurally studied. Crystals of compo sition [Mg(H 2 O) 2 (ur) 4 ](NO 3 ) 2 (I) are monoclinic, Z = 2, P2 1 /n, a = 6.449(1) Å, b = 17.670(2) Å, c = 7.578(1) Å; β = 91.637(2)°. In the structure of complex I, the central magnesium atom has octahedral geometry: the four carbamide molecules are in equatorial positions, and water molecules occupy axial positions.

Reactive Mechanosynthesis of Urea Ionic Cocrystal Fertilizer Materials from Abundant Low Solubility Magnesium- and Calcium-Containing Minerals

“…A detailed comparison of every reactant, product, and simulated product’s (obtained from the Cambridge Crystallographic Data Centre (CCDC)) XRD pattern of the reported molecular crystals in the literature is shown. The XRD patterns were simulated of the target product crystals using conventional solution-based routes of CaSO 4 ·4CO­(NH 2 ) 2 , Ca­(H 2 PO 4 ) 2 ·4CO­(NH 2 ) 2 , Ca­(NO 3 ) 2 ·4CO­(NH 2 ) 2 , MgSO 4 ·6CO­(NH 2 ) 2 ·0.5H 2 O, Mg­(H 2 PO 4 ) 2 ·4CO­(NH 2 ) 2 , and Mg­(NO 3 ) 2 ·4CO­(NH 2 ) 2 ·2H 2 O . Unsurprisingly, the overall urea conversion and the corresponding product distribution were different from those obtained during the mechanohemistry of pure magnesium and calcium salts and urea .…”

“…In MgO case for this adduct, trace amounts of secondary unidentified product was formed as observed by the peaks at 2Θ of 15, 31, and 49°. An unidentified adduct was formed when all three magnesium minerals were reacted to yield the corresponding nitrate, which did not match the Mg­(NO 3 ) 2 ·4CO­(NH 2 ) 2 ·2H 2 O crystalline pattern . We hence labeled it as Mg­(NO 3 ) 2 · x CO­(NH 2 ) 2 · y H 2 O in Figure .…”

“…This work provides for novel mechanochemical route to yield urea ionic cocrystals from the alkaline (Mg or Ca) low solubility minerals and urea inorganic acid cocrystals. These ionic cocrystals have otherwise been synthesized through solution-based methods, necessitating large volume solution handling, crystallization, and evaporation. − , The resulting sulfates, phosphates, and nitrates improve urea nitrogen management and decrease its hydrolysis rate. Additionally, the resulting fertilizer materials can be seen as a further alternative to urea acid fertilizers, which were previously synthesized on an industrial scale but suffer from high hygroscopicity.…”

“…The XRD patterns were simulated of the target product crystals using conventional solution-based routes of CaSO 4 • 4CO(NH 2 ) 2 , 52 Ca(H 2 PO 4 ) 2 •4CO(NH 2 ) 2 , 53 Ca(NO 3 ) 2 •4CO- 53 and Mg(NO 3 ) 2 •4CO(NH 2 ) 2 •2H 2 O. 56 Unsurprisingly, the overall urea conversion and the corresponding product distribution were different from those obtained during the mechanohemistry of pure magnesium and calcium salts and urea. 12 However, we were able to convert most of our insoluble mineral precursors at the considerable conversion into the same urea ionic cocrystal products.…”

“…An unidentified adduct was formed when all three magnesium minerals were reacted to yield the corresponding nitrate, which did not match the Mg(NO 3 ) 2 • 4CO(NH 2 ) 2 •2H 2 O crystalline pattern. 56 We hence labeled it as Mg(NO 3 ) 2 •xCO(NH 2 ) 2 •yH 2 O in Figure 2. A series of varying composition magnesium nitrate−urea ionic cocrystals was previously synthesized using ternary systems of magnesium nitrate, urea, and water.…”