R. M. Zakirova

Synthesis and structure of cobalt(II) complexes with nitrilotris(methylenephosphonic) acid [Co(H2O)3{NH(CH2PO3H)3}] and Na4[Co{N(CH2PO3)3}] ·13H2O

Nitrilotris(methylenephosphonato)triaquacobaltum(II) and tetrasodium nitrilotris(methylenephosphonato)cobaltate(II) tridecahydrate were synthesized and studied. The crystals of [Co(H2O)3{NH(CH2PO3H)3}] (I) are monoclinic, space group P21/c, Z = 4, a = 9.2092(2), b = 16.0540(2), c = 9.7445(2) Å, β = 115.778(3)°. The coordination polyhedron of cobalt is a distorted octahedron formed by oxygen atoms. The organophosphorus ligand bridges the neighboring cobalt atoms. The crystals of Na4[Co{N(CH2PO3)3}] · 13H2O (II) are triclinic, space group, P

Synthesis, structure, and properties of nickel complexes with nitrilotris(methylenephosphonic acid) [Ni(H2O)3N(CH2PO3H)3] and Na4[Ni(H2O)N(CH2PO3)3] ∙ 11H2O

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Synthesis, structure, and properties of the stabilized coordination chrome(II) complex with nitrilotris(methylenephosphonic) acid [CrII(H2O)3-μ-NH(CH2PO3H)3]

, Z = 2, a = 11.2240(8), b = 11.2663(8), c = 12.3296(8) Å, α = 108.513(6)°, β = 97.261(6)°, γ = 117.056(7)°. The cobalt atom is coordinated to form a distorted trigonal bipyramid. Complex II is a chelate in which the cobalt atom closes three five-membered N-C-P-O-Co rings sharing the Co-N bond. The Co atom is incorporated in the Co-O-Co-O ring. Upon dissolution in water, this ring is opened and cobalt(II) atom is hydrolyzed.

Nitrilotris(methylenephosphonato)potassium K[μ6-NH(CH2PO3)3H4]: Synthesis, structure, and the nature of the K–O chemical bond

A new non-electrolyte complex of iron(II), {Fe[μ-NH(CH2PO3H)3](H2O)3}, has been synthesized and investigated. The crystallographic characteristics of the complex are as follows: sp. gr. P21/c, Z = 4, a = 9.2619(3) Å, b = 16.0548(3) Å, c = 9.7570(3) Å, and β = 115.685(4)°. The iron atom is octahedrally coordinated by the three phosphonate oxygen atoms and three water molecules in the meridional configuration. The complex has a coordination polymer structure; each Fe atom closes the eight-membered chelating cycle Fe–O–P–C–N–C–P–O, and one of the phosphorus atoms of this cycle is bound with an iron atom of a neighboring structural unit.

Chelate complexes of lead(II) with nitrilotris(methylenephosphonic) acid [Pb{μ5-NH(CH2PO3H)3}] and Na4[Pb2(H2O)2{μ3-N(CH2PO3)3H2}2] · 10H2O: Synthesis, structure, and asymmetry of lone 6s pair

Nitrilotris(methylenephosphonato)triaquanickel and tetrasodium nitrilotris(methylenephosphonato) aquanickelate undecahydrate were synthesized and characterized. The crystal of [Ni(H2O)3N(CH2PO3H)3] is composed of linear coordination polymers and belongs to sp. gr. P21/c, Z = 4, a = 9.17120(10) Å, b = 16.05700(10) Å, c = 9.70890(10) Å, β = 115.830(2)°. The Ni atom is in an octahedral coordination formed by two oxygen atoms of one phosphonate ligand, one oxygen atom of another ligand molecule, and three water molecules in a meridional configuration. The crystal of Na4[Ni(H2O)N(CH2PO3)3] ∙ 11H2O has an island dimeric chelate structure and belongs to sp. gr. С2/c, Z = 8, a = 18.7152(2) Å, b = 12.05510(10) Å, c = 21.1266(2) Å, β = 104.4960(10)°. The Ni atom has a slightly distorted octahedral coordination involving one nitrogen atom and closes three five-membered N–C–P–O–Ni rings sharing the Ni–N bond.

Aquanitrilotris(methylenephosphonato)bis(dimercury(I)) hydrate, [(Hg2)2(H2O)N(CH2PO3)3H2] · H2O: Synthesis, structure, and properties

Thermogravimetry, XPA, and ESCA were used to study the thermal stability and decomposition mechanism of [Cu(H2O)3μ-N(CH2PO3)3H4], [Zn(H2O)3μ-N(CH2PO3)3H4], Na8[CuN(CH2PO3)3]2·19H2O, and Na4[ZnN(CH2PO3)3]·13H2O in the atmosphere of air and argon. It was shown that the decomposition point, decomposition mechanism, and composition of the products being formed depend on the composition and structure of coordination compounds, and for Na8[CuN(CH2PO3)3]2·19H2O m Na4[ZnN(CH2PO3)3]·13H2O, also on the composition of the atmosphere. The stability of the complexes is affected by the configuration of the coordination polyhedron and by the electron density distribution in the coordination environment of a metal. The complex Na4[ZnN(CH2PO3)3] has the highest thermal stability in both air and argon (onset of decomposition at about 400°C).

The trisodium monohydrogen-nitrilo-tris-methylenephosphonato-hydroxylaminato-nitrosyl-molybdate octahydrate Na3[Mo(NO)(NH2O){N(CH2PO3)3H}] · 8H2O: Synthesis, structure, and nature of coordination bond of transition metal with non-innocent ligand

The chrome(II) complex [CrII(H2O)3µNH(CH2PO3H)3] is synthesized and studied. The crystals are monoclinic, space group P21/c, Z = 4, a = 9.28230(10), b = 16.0778(2), c = 9.79790(10) Å, β = 116.081(2)° (CIF file CCDC 1045098). The chrome atom is coordinated at the vertices of the distorted octahedron by three atoms of the water molecules and three O atoms of two tridentate chelate-bridging ligands NH(CH2PO3H)3 (L = H4NTP2–). The compound is a linear polymer. The eight-membered cycle Cr–O–P–C–N–C–P–O is closed upon the coordination of ligand L by two oxygen atoms (O(1), O(6)). The O(5) atom is bound to the adjacent chrome atom. The stabilization of the oxidation state of Cr(II) is due to the delocalization of the electron density drawn aside from the metal atom in the PO3 groups.

Aquanitrilotris(methylenephosphonato)dirubidium [Rb2(H2O){μ12-NH(CH2PO3H)3}]: Synthesis and structure

The crystal structure of nitrilotris(methylenephosphonato)potassium K[μ6-NH(CH2PO3)3H4]—a three-dimensional coordination polymer—was determined. The potassium atom is coordinated by seven oxygen atoms belonging to the six nearest ligand molecules, resulting in distorted monocapped octahedral coordination geometry. The complex contains the four-membered chelate ring K–O–P–O. The K–O chemical bond is predominantly ionic. Meanwhile, the bonds of the potassium atom with some oxygen atoms have a noticeable covalent component. In addition to coordination bonds, the molecules in the crystal packing are linked by hydrogen bonds.