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All industrial processes especially metal cleaning procedures dealing with dangerous solutions should be used as little as possible and their emission into the aquatic environment should be controlled. In this study, in order to find a proper and efficient cleaning process, lead pollution was removed from the solid matrix by using a cleaner solution containing EDTA and H2O2 as chelating and oxidizing agents respectively. An orthogonal array design (OAD), OA9, was employed as a chemometric method for the optimization of the procedure. The results of experiment revealed that, lead pollution (~3 g) at the predicted optimum condition can be effectively removed from the solid matrix during 4 minutes. Cleaning quality was checked by SEM/EDAX, ICP and UV spectroscopy methods. Finally, the results of this investigation showed that H2O2/EDTA system can be considered as a novel, safe and an efficient cleaning solution, due to its proper processing parameters. [ABSTRACT FROM AUTHOR]

Some new carbacylamidophosphate derivatives with the general formula RC(O)NHP(O)[NH(C5H9)]2: (R=CCl3), 1a; (R=CHCl2), 2a; (R=CH2Cl), 3a; (R=CF3), 4a; (R=C6H5), 1b; (R=p-Cl-C6H4), 2b; (R=p-Br-C6H4), 3b; (R=p-Me-C6H4), 4b; were synthesized and characterized by 1H, 13C, 31PNMR and IR spectroscopy and elemental analysis. The crystalline solids of 1a and 4b were studied by single crystal X-ray diffraction analysis. The dimeric aggregate and the centrosymmetric dimer formed via intermolecular N-H....O=P and N-H....O=C hydrogen bonds in 1a and 4b, respectively. In all the synthesized molecules, similar spectral patterns were obtained in the 13C NMR spectra for carbon atoms of cyclic amines with 2JPNC = 0 and 3JPNC ranging from 4 to 6 Hz. [ABSTRACT FROM AUTHOR]

In this study, the synthesis and spectroscopic characterization of new phosphoramides based on 3-amino-5-methylisoxazole with the formula R2P(O)[NH-C4H4NO], R = C6H5O (1), C6H5 (2), RP(O)[NH-C4H4NO]2, R = C6H5O (3), CH3-C6H4O (4), C6H5NH (5), (C6H5)ClP(O)[NH-C4H4NO] (6) and two lanthanide complexes [Ln(2)2(NO3)3(EtOH)]·EtOH, Ln(III) = Ce (7) and Eu (8), have been reported. The structural study of (3) shows the presence of two conformers (crystallographically independent molecules) in the crystalline lattice, caused by different orientations of the phenyl and isoxazole rings. For (3), the intermolecular interactions have been studied by Hirshfeld surface analysis and fingerprint plots. Furthermore, the electronic and energy aspects of hydrogen bonds between molecules of (3) have been explored by density functional theory (DFT) calculations. X-ray crystallography of complexes (7) and (8) reveals that two phosphoramide ligands take part in coordination to the metal, one as monodentate from O(phosphoryl), and the other one as chelate through O(phosphoryl) and N(ring). The complexes are also composed of two conformers in the solid-state structure. Quantum theory of atoms in molecules (QTAIM) analysis discloses the electrostatic nature of the Ln-ligand interaction.

The bisphosphoramidate (C(6)H(5)O)(2)P(O)NH(CH(2))(4)NHP(O)(OC(6)H(5))(2) crystallizes in two polymorphs, one (ndl) with a needle habit from tetrahydrofuran (THF)/ethanol and another (prm) which forms prisms from H(2)O/ethanol. The molecules in the two forms differ from each other in some torsion angles and the orientation of the diaminobutane bridge, although the differences between the similar bond lengths are not significant for the two polymorphs. The geometry optimizations at the B3LYP/6-31+G* level for isolated molecules show that the two conformers which exist in the crystalline state also represent local gas-phase energy minima. The decrease in the N-H distance from the optimized to the crystal structures has been described in terms of the decrease in electron density (ρ) at the bond-critical point (b.c.p.) of the N-H bond path when the molecule participates in hydrogen bonding, comparing the results of atoms-in-molecules (AIM) and natural bond orbital (NBO) analyses for fully optimized structures ndl and prm with their hydrogen-bonded model clusters.

All industrial processes especially metal cleaning procedures dealing with dangerous solutions should be used as little as possible and their emission into the aquatic environment should be controlled. In this study, in order to find a proper and efficient cleaning process, lead pollution was removed from the solid matrix by using a cleaner solution containing EDTA and H2O2 as chelating and oxidizing agents respectively. An orthogonal array design (OAD), OA9, was employed as a chemometric method for the optimization of the procedure. The results of experiment revealed that, lead pollution (-3 g) at the predicted optimum condition can be effectively removed from the solid matrix during 4 minutes. Cleaning quality was checked by SEM/EDAX, ICP and UV spectroscopy methods. Finally, the results of this investigation showed that H2O2/EDTA system can be considered as a novel, safe and an efficient cleaning solution, due to its proper processing parameters.

A phosphoric triamide with the formula (4-CH(3)-C(6)H(4)NH)P(O)(NC(4)H(8)O)(2) has been synthesized and characterized. X-ray crystallography at 120 K reveals that the title compound is composed of two symmetrically independent molecules in the solid state. Density functional theory (DFT) calculations reveal that two conformers A and B are very close to each other from an energy point of view. Thus there is equal chance that the presence of two conformers in the lattice may lead to hydrogen-bonded chains with an ABABAB arrangement. Hydrogen bonds of the type O(P)...H-N (O(P) being the phosphoryl O atom) are established between the two conformers with binding energies of -18.8 and -20.3 kJ mol(-1) (at B3LYP/6-31+G*). The electronic delocalization LP(O(P)) → σ*(N-H), LP(O(P)) being the lone pair of O(P), leads to a decrease in the strength of the N-H bond during hydrogen bonding between the conformers. The charge density (ρ) at the bond critical point (b.c.p.) of N-H decreases by ∼0.012-0.014 e Å(-3) when the molecule participates in hydrogen bonding. This may explain the red shift of the ν(N-H) stretching frequency from a single molecule in the gas phase to a hydrogen-bonded one in the solid state.

The title salt, [P(NHCH(2)C(6)H(5))(4)](+)·Cl(-), crystallizes with the P atom and Cl(-) anion lying on a twofold rotation axis. The P atom has a slightly distorted tetra-hedral geometry with two classes of N-P-N angles [101.15 (10) and 100.55 (11)° and 113.07 (9) and 114.83 (8)°] and the environments of sp(2)-hybridized N atoms are essentially planar (sum of angles = 359.9 and 360.1°). In the crystal, the phospho-nium ion inter-acts with each neighboring chloride ion via two approximately equal N-H⋯Cl inter-actions, forming parallel chains along the c axis.

New phosphoramidates with the formula RC(O)N(H)P(O)X(2), R = 2-NO(2)-C(6)H(4), 3-NO(2)-C(6)H(4) and 4-NO(2)-C(6)H(4), X = N(CH(2)CH(3)) (1)-(3), NC(4)H(8) (4)-(6), and NC(4)H(8)O (7)-(9) were synthesized and characterized by (1)H, (13)C, (31)P NMR and IR spectroscopy, and elemental analysis. The reaction of (9) with hydrated lanthanide(III) nitrate leads to ten- or nine-coordinated complexes, (10)-(13). The crystal structure has been determined for (3), (5), (9), (10) and (13). In contrast to all of the previously reported similar phosphoramidate compounds, the -C(O)-N(H)-P(O) skeleton in the free ligand (9) shows a cisoid conformation, with the C=O and P=O double bonds adopting a nearly syn conformation. Quantum chemical calculations were applied for clarifying this exceptional conformational behavior. The monodentate neutral ligand (9) is coordinated to the metal ions via the phosphoryl O atom, adopting the usual anti conformation between the C=O and P=O groups.