V. G. Petrov

Synthesis, structure, and properties of nitrilo-tris(methylenephosphonato)-triaquairon(II) {Fe[µ-NH(CH2PO3H)3](H2O)3}, as an ingredient of anticorrosive protective coatings on the steel surface

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.

Thermal stability and thermal decomposition mechanism of nitrilotris(methylene phosphonate) complexes of copper and zinc with varied coordination

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).

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

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.

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

Two complexes of Pb(II) with nitrilotris(methylenephosphonic) acid are synthesized and their crystal structures are determined. Nitrilotris(methylenephosphonato)lead(II) [Pb{μ5-NH(CH2PO3H)3}] is a coordination 3D polymer; space group Pī, Z = 2. The coordination polyhedron of Pb is a distorted pentagonal bipyramid with the N atom at one of the equatorial positions. Tetrasodium bis[aquanitrilotris(methylenephosphonatoplumbate( II)] decahydrate Na4[Pb2(H2O)2{μ3-N(CH2PO3)3H2}2] · 10H2O crystallizes in space group Pī, Z = 2. The degree of asymmetry of the coordination polyhedra of lead atoms characterizing the localization of the lone 6s electron pair is estimated.

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

A reaction of dimercury(I) dinitrate with nitrilotris(methylenephosphonic acid), N(CH2PO3)3H6, gave the complex [(Hg2)2(H2O){N(CH2PO3)3H2}] · H2O. The crystals of the complex are triclinic, space group

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

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Dihydronitrilotris(methylenephosphonato)dimercury(II)mercury(I) [(Hg 2 I )Hg II N(CH 2 PO 3 ) 3 H 2 ]: Synthesis and Structure

, Z = 2, a = 8.3436(3), b = 9.0744(3), c = 11.1124(4) Å, α = 91.875(3)°, β = 104.452(3)°, γ = 92.195(3)° (CIF file CCDC no. 1051860). The atoms of either dimercury cation are coordinated differently, making up a distorted tetrahedron and a distorted trigonal bipyramid. The ligand is coordinated to the Hg atoms through seven donor atoms: six (out of nine) O atoms and a N atom. The coordination involves the formation of chelate rings: two four-membered, three five-membered, a six-membered, and an eight-membered ring (CIF file CCDC no. 1051860).

Bis(nitrilo)tris(methylenephosphonato)dodecaaquatrihydrohexasodium Europium(III) [EuNa6H3(H2O)12{N(CH2PO3)3}2]: Synthesis and Structure

The sodium salt of heteroleptic molybdenum complex with nitrilotris(methylenephosphonic) acid (NTP), hydroxylamine, and nitrogen(II) oxide Na3[Mo(NO)(NH2O){N(CH2PO3)3H}]· 8H2O was synthesized, isolated, and studied (space group P21/c, Z = 4, a = 9.7385(2), b = 10.2542(2), c =21.6517(3) Å, β = 93.7060(10)°). The nitrilotris(methylenephosphonate) ion is monoprotonated at the PO3 group. The nitrogen atom is deprotonated and coordinates the Mo atom; the NTP denticity is 4. Hydroxylamine is ionized according to the acid type and is bidentate. The Mo–NO group is almost linear (176.31(19)° angle; Mo–N, 1.7599(13) Å; ν(N–O), 1756 cm–1), the electron density distribution attests to the formation of an Mo–N π-bond. The Mo coordination polyhedron is a distorted pentagonal bipyramid. Two Na ions are coordinated at the vertices of a distorted octahedron and the third one forms a distorted tetrahedral geometry. (CIF file CCDC no. 1543700.)