Syntheses, spectroscopic characterization and crystal structures of some new phosphoramidates and an organotin(IV) complex of N-(4-fluorobenzoyl)-N′,N″-bis(piperidinyl)phosphoric triamide

Phosphoramides bearing isoxazole derivative: spectroscopic and structural characterization, study of hydrogen-bonding interactions and two lanthanide complexes (LnIII = Ce and Eu)

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.

Synthesis and structural study of some new phosphorus(v) hydrazide compounds: spectroscopic evidence and a theoretical approach

New phosphorus(v) hydrazides based on methyl and t-butyl carbazates are reported. Experimental trends are elucidated using DFT calculations.

Synthesis, spectroscopic characterization and theoretical calculations of ClF2CC(O)NPCl3 ([chloro(difluor)acetyl]phosphorimidic trichloride)

The synthesis of [chloro(difluor)acetyl]phosphorimidic trichloride (ClF2CC(O)NPCl3), together with a tentative assignment of the vibrational, NMR and mass spectra, are reported. Quantum chemical calculations (MP2 and B3LYP methods with 6-311+G(d) and 6-311+G(2df,p) basis sets) predict three stable conformers in the gas phase (syn, gauche and anti, defined according to the rotation around both the ClCCN and the CCNP dihedral angles). However, only a single C1 symmetry conformer is observed in the liquid phase, possessing the CO double bond in synperiplanar orientation with respect to the PN double bond, and the ClC bond distorted from the plane defined by the CC(O)NP entity. A Natural Bond Orbital (NBO) analysis was carried out for the title compound and related molecules in order to provide an explanation about the electronic properties.

Nanoparticles of novel organotin(IV) complexes bearing phosphoric triamide ligands

Four novel organotin(IV) complexes containing phosphoric triamide ligands were synthesized and characterized by multinuclear ((1)H, (31)P, (13)C) NMR, infrared, ultraviolet and fluorescence spectroscopy as well as elemental analysis. The (1)H NMR spectra of complexes 1-4 proved that the Sn atoms adopt octahedral configurations. The nanoparticles of the complexes were also prepared by ultrasonication, and their SEM micrographs indicated identical spherical morphologies with particles sizes about 20-25 nm. The fluorescence spectra exhibited blue shifts for the maximum wavelength of emission upon complexation.

A second monoclinic polymorph of N-[bis-(morpholin-4-yl)phosphino-yl]-4-fluoro-benzamide with the P2(1)/n space group

A second monoclinic polymorph of the title mol­ecule, C₁₅H₂₁FN₃O₄P, is reported in the space group P2₁/n and compared to the previously reported C2/c space group [Gholivand et al. (2006 ▶). Polyhedron, 25, 711–721]. The asymmetric unit of the title compound consists of two independent mol­ecules. The P atoms adopt a distorted tetra­hedral environment. In the C(O)NHP(O) fragment, the P=O and the N—H groups are in a syn conformation with respect to each other and in the crystal, inter­molecular N—H⋯O=P hydrogen bonds form dimeric aggregates.

Solid-state and gas-phase structures of two conformers of N-(4-methylphenyl)-N′,N′′-bis(morpholinyl) phosphoric triamide; insights from X-ray crystallography and DFT calculations

A phosphoric triamide with the formula (4-CH3—C6H4NH)P(O)(NC4H8O)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 OP...H—N (OP 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(OP) → σ*(N—H), LP(OP) being the lone pair of OP, 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.

Syntheses, spectroscopic study and X-ray crystallography of some new phosphoramidates and lanthanide(III) complexes of N-(4-nitrobenzoyl)-N′,N′′-bis(morpholino)phosphoric triamide

New phosphoramidates with the formula RC(O)N(H)P(O)X 2, R = 2-NO2—C6H4, 3-NO2—C6H4 and 4-NO2—C6H4, X = N(CH2CH3) (1)–(3), NC4H8 (4)–(6), and NC4H8O (7)–(9) were synthesized and characterized by 1H, 13C, 31P 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.