Facile and one-pot synthesis of magnetic nanoparticles containing mesoporous carbon

Abstract

Magnetic nanoparticles containing mesoporous carbon materials have been synthesized via an one-pot strategy associated with a direct carbonization process from resol, metal ion sources (Co(NO₃)₂·6H₂O, Ni(NO₃)₂·6H₂O) and triblock copolymer F127. The samples exhibited well-ordered 2-dimensional (2-D) hexagonal mesostructures with p6mm symmetry. The Brunauer-Emmet-Teller (BET) surface area and pore size 1.0wt%Co- and 1.0wt%Ni-FDU-15(700) with 1.0?wt% Co and 1.0?wt% Ni content were 700, 528 m²/g and 17.2, 36.4 Å, respectively, after carbonization at 700?°C. The saturation magnetization values of 1.0wt%Co- and 1.0wt%Ni-FDU-15(700) after carbonization at 700?°C were 1.3 and 1.0?emu/g, respectively.     

Effect of the surfactant nature on the thermo-stability of surface modified SnO2 nanoparticles

The modification of particle surface properties by the addition of small surfactant molecules in the initial sol is one strategy to minimize the strong tendency to aggregation and coarsening of nanoparticles prepared from the sol–gel process. In this work, the effect of the nature of the surfactant, Tiron^® ((OH)₂C₆H₂(SO₃Na)₂ · H₂O, anionic) or Catechol^® (C₆H₄-1,2-(OH)₂, non-ionic) or Maptac^® ([N(CH₃)₃(CH₂)₃NHCOC(CH₂CH₃)]⁺Cl^?, cationic), grafted on the SnO₂ nanoparticles on the mesoporosity of powders fired at 600 °C is presented. SnO₂ powders were prepared from an one-pot sol–gel route in which the hydrolysis of SnCl₄ · 5H₂O in aqueous solution was carried out in presence of the surfactant. The Fourier transform infrared (FTIR) spectroscopy and gravimetric and differential thermo-analysis (TG/DTA) results show that the thermo-stability of surface grafted SnO₂ nanoparticles obeys the following series: Tiron^® > Catechol^® > Maptac^®. The N₂ adsorption isotherms results evidence that the mesopores texture (specific surface area, pore volume and average pore size) can be tuned in a controlled way by increasing the amounts of Tiron^® or Catechol^® molecules grafted on the surface of SnO₂ nanoparticles.     

Crystal Structure and Hirshfeld Surface Analysis of Bis(3-thienoyl) Disulfide

The spectroscopic characterization (¹H, ¹³C{¹H} NMR, UV–Vis) and single-crystal X-ray diffraction (scXRD) analysis accomplished by inspection of the Hirshfeld surface of bis(3-thienoyl) disulfide (1) is described. The title compound 1 crystallizes in the monoclinic space group P2₁/n. The unit cell parameters are a?=?7.9959(3) Å, b?=?6.4348(3) Å, c?=?22.4924(9) Å, β?=?100.108(4)°, V?=?1139.32(8) ų, Z?=?4, R_gt(F)?=?0.0278, wR_ref(F²)?=?0.0667. The packing of 1 is dominated by S?O and S?S interactions, giving a 2D layer structure parallel to (101). The X‐ray crystal structure analysis revealed the packing of 1 is dominated by S?O and S?S interactions, giving a 2D layer structure parallel to (101). The intermolecular interactions in 1 were analyzed using the Hirshfeld surface method including 2D fingerprint plots and enrichment ratios (E), which shows that the most favored intermolecular contacts are the O?H and C?S indicated by E values above 1.30. The interaction energies between molecular pairs revealed the importance of the weak O?H and C?S interactions in stabilizing the molecular structure of 1.

Graphic Abstract

Single crystal X-ray structure analysis, DFT calculations and Hirshfeld surface analysis to identify intermolecular interactions within the solid state structure of bis(3-thienoyl) disulfide (1).

     

Synthesis by precipitation method and investigation of SnO2 nanoparticles

In this paper the synthesis of SnO₂ nanoparticles with average particle size up to about 70 nm using SnCl₂2H₂O and NH₄OH in 1‐botanol solution by the precipitation method is reported and the inhibition of sodium dodecyl sulphate (SDS) on the SnO₂ particle growth is investigated by soaking SnO₂precursor in the SDS solution for 24 h. The as‐prepared SnO₂and SDS modified‐SnO₂ powders, then, were calcined at different temperatures and the X‐ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT‐IR) were used to characterize the output samples. The XRD results reveal that the structure of tin‐dioxide is tetragonal rutile and the as‐prepared SnO₂ nanoparticles grow with increasing the annealing temperature, while the SDS treatment prevents the particle growth under the same condition. Furthermore, the FT‐IR results indicate the formation of tin‐hydroxyl group which are then converted into tin‐dioxide with heat treatment. Further characterization of the samples by the transmission electron microscopy (TEM) and the photoluminescence (PL) spectroscopy was carried out. The room temperature PL spectra of SnO₂exhibits broad and strong peak attributed to the surface defects such as oxygen vacancies and intensity of which decreases with the increase in particle size. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Fabrication and characterization of ‘self-binding’ nanocrystalline SnO2 powder based thick film ethanol sensor

Sensing response of ‘self-binding’ nanoparticles of tin dioxide powder deposited on alumina substrate has been investigated. The nanocrystalline SnO₂ powder has been derived from stannic chloride. It has been prepared through fine crystallization in liquid phase. SnO₂ powder has been characterized using SEM, TEM and XRD techniques, which reveal that the average crystallite size is of 12 nm. The slurry blobs deposited on alumina substrate of the powder-thus-prepared have been studied for sensing response to ethanol at various temperatures and concentrations. The observations reveal that the material prepared is ‘self-binding’ and is very sensitive even without catalyst.     

Synthesis and X-ray diffraction study of (Cs0.5Ba0.25)[UO2(CH3COO)3] and Ba0.5[UO2(CH3COO)3]

Uranyl triacetate complexes (Cs_0.5Ba_0.25)[UO₂(CH₃COO)₃] (I) and Ba_0.5[UO₂(CH₃COO)₃] (II) are synthesized for the first time and their structures are determined by X-ray diffraction. Both compounds crystallize in the cubic crystal system. The crystal data are as follows: a = 17.3289(7) ?, V = 5203.7(4) ?³, space group I2₁3 and Z = 16 (I); a = 17.0515(8)?, V = 4957.8(4) ?³, space group I $ \bar 4 $ \bar 4 3d, and Z = 16 (II). In I and II, as in all uranyl triacetates studied earlier, the coordination polyhedron of the uranium atom is a hexagonal bipyramid whose vertices are occupied by the oxygen atoms of the uranyl and three acetate groups. The uranium-containing group belongs to the AB ₃⁰¹ (A = UO₂²⁺, B ⁰¹ = CH₃COO⁻) crystal chemical group of uranyl complexes. It was found that compound II is isostructural to the (Rb_0.50Ba_0.25)[UO₂(CH₃COO)₃] studied earlier.     

Preparation of New Fibrous Organic-Inorganic Layered Compounds Derived from Zinc Hydroxyde

Abstract

A new preparation method of the fibrous organic-inorganic nanohybrids was established by the reaction of Zn(OH)₂ with various organic carboxylic acids. Interlayer spacings of the reaction products of Zn(OH)₂ with benzoic acid and p-phenyl azobenzoic acid were 1.46 and 2.04 nm, and these reaction products have layered structure. In IR spectra, new peaks of RCOO-Zn band appeared at around 1400 cm^?1 and 1550 cm^?1 indicating that hydroxyl groups reacted with organic carboxylic acids. SEM images of these reaction products showed fibrous morphology. The TEM image showed that the layer structure was constructed along the fiber direction.     

Synthesis and Crystal Structure of Copper II and Silver I Complex with 1,4-diazabicyclo[2.2.2]octane[Cu(CBC)2(Dabco)(H2O)] n (1) and [Ag2(HBC)2(Dabco)] n (2)

Two 1D polymeric complex, [Cu(CBC)₂(Dabco)(H₂O)] _n (1) and [Ag₂(HBC)₂(Dabco)] _n (2) have been synthesized and characterized by X-ray single crystal analysis, where CBCH is p-chlorobenzoic acid, HBCH 2 is 2-hydroxybenzoic acid and Dabco is 1,4-diazabicyclo[2.2.2]octane. Complex 1 has been obtained in high yield by hydrothermal synthesis from CuO and CBCH and Dabco, and complex 2 has been obtain by evaporation of the solvent from silver salicylate and Dabco, 1 crystallizes in the orthorhombic space group Pmn2 ₁ with a = 24.3310(5) ?, b = 6.9050(6) ?, c = 5.9980(5) ?, Z = 2, V = 1007.70(4) ?³ and Dx = 1.657 g cm⁻³, 2 crystallizes in the monoclinic space group P2 ₁ /m with a = 10.292(3) ?, b = 6.913(2) ?, c = 14.417(4) ?, β = 95.660(5), Z = 2, V = 1020.8(5) ?³ and Dx = 1.959 g cm⁻³. The final R value is 0.0302 for 1323 measured reflections for 1 and the final R value is 0.0684 for 1545 measured reflections for 2. The atomic arrangement is built by infinite one-dimensional polymeric chain in both complexes. These chains are cross-linked by hydrogen bonds involving the coordinated water molecules to form a two-dimensional framework in complex 1.     

Crystal structure of chloro[1-hydroxyethane-1,1-diphosphonato(3−)]ditin(II) monohydrate Sn2(HL)Cl · H2O

The synthesis and X-ray structure analysis of Sn₂(HL)Cl · H₂O, where HL ^3? is the anion of 1-hydroxyethane-1,1-diphosphonic acid, are reported. The coordination polyhedra of two independent tin(II) atoms are the Sn(1)O₂Cl and Sn(2)O₃ trigonal pyramids, in which one of the vertices is occupied by a lone electron pair (Sn-O, 2.144–2.218 Å and Sn-Cl, 2.573 Å). The pyramids are complemented by weaker Sn?O and Sn?Cl contacts to form severely distorted (3 + 3) octahedra. The SnO₂Cl and SnO₃ pyramids are linked by the HL ^3? bridging ligands into the [Sn₂(HL)Cl]₆ cyclic molecules, which, in turn, are joined by additional Sn?O, Sn?Cl, O(H₂O)?O(L), and O(H₂O)?Cl contacts with each other and with crystallization water molecules into a three-dimensional framework.     

The preparation and crystal structures of [Ru(bpy) (η2-tpy)(CO)CH2OAc]PF6 and [Ru(η3-tpy)(CO)CH2OAc] PF6 (bpy = 2,2′-bipyridine; tpy = 2,2′:6′,2″ terpyridine)

The first titled compound, 1, was obtained by treating [Ru(bpy)(η²-tpy)(CO)CH₂OH]PF₆ with acetic anhydride. Heating 1 in acetonitrile afforded 2, [Ru((η³-tpy)(MeCN)(CO) CH₂OAc]PF₆. Allowing 2 to stand in CH₂Cl₂ followed by concentration and precipitation afforded the second titled compound, 3 ([Ru((η³-tpy)(CO)–CH₂OAc]PF₆), in which the acetoxymethyl group had become bidentate. Crystal data for 1, monoclinic crystal system, space group C2/c, a=26.001(4) ?, b=13.0395(18) ?, c=20.718(3) ?, β=107.700(2)°, V=6691.7(16) ?³, Z=8; for 3, monoclinic crystal system, space group P2₁/n, a=10.864(2) ?, b=16.922(4) ?, c=11.127(2) ?, β=90.907(3)°, V=2045.4(8) ?³, Z=4.     

Synthetic and structural studies of the trans bis(2-N-H-pyrrolylcarbaldimine) complexes of nickel(II) and palladium(II)

The molecular bis(2-N-H-pyrrolylcarbaldimine)nickel(II) and palladium(II) complexes are isolated in moderate yield (30–35%) from in situ assembly of the Schiff base with metal(II) salt, base, and pyrrole-2-carbaldehyde in aqueous ammonia solution. The nickel(II) complex, 1, is monoclinic, space group P2₁/c, with a=11.289(6) ?, b=5.611(3) ?, c=8.287(5) ?, β=111.620(6)°, and V=488.0(5) ?³ with Z=2, for d _calc=1.667 Mg/m³. The palladium analog, 2, is isomorphous, space group P2₁/c, with a=11.481(3) ?, b=5.5738(10) ?, c=8.276(2) ?, β=110.923(12)°, and V=494.7(2) ?³ with Z=2, for d _calc=1.965 Mg/m³. In both crystal structures, the metal resides on an inversion center. In the IR spectra, ν(C=N) appears at 1561 cm⁻¹ in 1, and 1557 cm⁻¹ in 2, while ν(N–H) shows at 3345 cm⁻¹ and 3335 cm⁻¹, respectively. The ¹H-nmr spectra reveal the C–H and N–H protons of the imine group as sharp and broad doublets, respectively, at 7.62 and 8.38 δ in 1 and at 7.92 and 9.73 δ in 2.     

Synthesis and crystal structure of Mn(II) and Zn(II) complexes with 1,3,5-tris(carboxymethoxyl)benzene ligand

Two complexes (H₂bipy)[M₂(TB)₂(H₂O)₈]·5H₂O (M = Mn 1, Zn 2) (bipy = 4,4′-bipyridine, H₃TB = 1,3,5-tris(carboxymethoxyl)benzene) were synthesized by the reaction of the corresponding metal salt with ligand H₃TB and 4,4′-bipy in an aqueous methanol solution at room temperature, respectively. Their structures were determined by single crystal X-ray diffraction analysis. Both complexes 1 and 2 crystallize in the triclinic space group with the crystal parameters of 1: a = 9.725(12) ?, b = 10.651(13) ?, c = 10.882(13) ?, α = 91.72(2)°, β = 96.41(2)°, γ = 97.72(2)°, V = 1109(2) ?³, Z = 1 and 2: a = 9.610(10) ?, b = 10.55(2) ?, c = 10.83(2) ?, α = 91.60(4)°, β = 95.32(2)°, γ = 97.73(4)°, V = 1082(3) ?³, Z = 1. Complexes 1 and 2 have the same dinuclear structure, in which each metal atom is six coordinated with distorted octahedral geometry by two oxygen atoms from two different TB³⁻ ligands and four ones from four coordinated water molecules. The dinuclear units are further linked by hydrogen bonding and π–π interactions to form the three-dimensional framework structure.     

The effect of organic linkers on the supramolecular structures of two new Ni(II) cyclen complexes (cyclen = 1,4,7,10-tetraazadodecane)

Two new nickel(II)(cyclen) coordination polymers, {[Ni(cyclen)·(bipy)]·(ClO₄)₂}_n (1) and [Ni(cyclen)]₂·(squa)·(ClO₄)₂ (2) have been synthesized and characterized structurally, where cyclen is 1,4,7,10-tetraazadodecane. Compound 1 crystallizes in the monoclinic system, space group C2/c, with a = 10.5339(17) ?, b = 14.565(2) ?, c = 16.133(3) ?, β = 102.799(2)°, V = 2413.4(7) ?³. Compound 2 crystallizes in the orthorhombic system, space group P _{nm a} with a = 25.722(3) ?, b = 11.1168(12) ?, c = 11.4580(13) ?, V = 3276.3(6) ?³. In both compounds, each Ni^II center is in a distorted octahedral coordinated environment with four N_cyclen atoms and two N_pyridine atoms from 4,4′-bipyridine linker for 1 and two O_aqueou atoms from the coordinated water for 2, respectively. The complex 1 exhibits infinite zigzag 1D chains by linking of 4,4′-bipyridine coordinated. In complex 2, 2D sheet supramolecule generated through self-assembling by hydrogen bond.     

Wide band-gap organic molecules containing benzodithiophene and difluoroquinoxaline derivatives for solar cell applications

Abstract

Two new semiconducting organic small molecules, namely BDTQ-BDT(EH) and BDTQ-BDT(OC), were prepared by attaching electron accepting 2,3-didodecyl-6,7-difluoro-5,8-di(thiophen-2-yl)quinoxaline (DTQ) unit on 2,6-position of electron donating 4,8-bis(2-ethylhexyloxy)benzo[1,2-b:4,5-b']dithiophene (BDT(EH)) and 4,8-bis(octyloxy)benzo[1,2-b:4,5-b']dithiophene (BDT(OC)) units. Molecule BDTQ-BDT(EH) showed higher thermal stability (5% weight loss temperature, T_d “349 ^оC), slightly lower band-gap (E_g “2.10?eV) and deeper highest occupied molecular orbital energy level (HOMO “–5.36?eV) level compared to those (T_d “336 ^оC, E_g “2.11?eV, and HOMO “–5.30?eV, respectively.) of the molecule BDTQ-BDT(OC). The organic solar cells (OSCs) made with the synthesized molecules as an electron donor and [6,6]-phenyl C₇₁ butyric acid methyl ester (PC₇₀BM) as an electron acceptor gave a maximum power conversion efficiency (PCE) of 1.20% and 0.83%, respectively, for BDTQ-BDT(EH) and BDTQ-BDT(OC). This study confirmed that the substituents attached on the 4,8-position of BDT unit greatly alter the properties of the resulting molecules.     

Synthesis and Characterization of Nickel(II) Complex of 3,14-Dimethyl-2,6,13,17-Tetraazatricyclo[14,4,01.18,07.12]Docosane Containing Pyrazine-2-Carboxylate Ligand

Abstract  

The reaction of [Ni(L)]Cl₂·2H₂O (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane) with pyrazine-2-carboxylic acid (H-pyc) yields mononuclear nickel(II) complex, [Ni(L)(pyc)₂]·2H₂O (1). This complex has been characterized by X-ray crystallography, electronic absorption and cyclic voltammetry. The crystal structure of 1 exhibits a distorted octahedral geometry with four nitrogen atoms of the macrocycle and two pyrazine-2-carboxylate ligands. It crystallizes in the triclinic system P-1 with a = 9.6643(17), b = 10.116(3), c = 16.99(4) ?, V = 1633(3) ?³, Z = 2. Electronic spectrum of 1 also reveals a high-spin octahedral environment. Cyclic voltammetry of 1 undergoes two waves of a one-electron transfer corresponding to Ni^II/Ni^III and Ni^II/Ni^I processes.     

Raman study of fluorine effects on silica with embedded SnO2 nanoparticles

Silica samples with embedded SnO₂ nanoparticles have been produced by sol–gel method with a synthesis modified by the introduction of fluorinated silicon precursors. The structural features of silica network and SnO₂ nanophase have been mapped inside the samples by means of confocal micro-Raman scattering spectroscopy. The results show that the detection of residual fluorine into the matrix as Si–F groups is accompanied by network dehydration, by intensity depletion of the D₂ peak assigned to three-member rings of coordinated tetrahedra, and by SnO₂ nanoparticles with much larger sizes than in fluorine-free material.     

Synthesis and Crystal Structures of 3,3,6,6-tetramethyl-9-(2,4-dichlorophenyl)-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione and 3,3,6,6-tetramethyl-9,10-di(4-methoxyphenyl)-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione

The title compounds 3,3,6,6-tetramethyl-9-(2,4-dichlorophenyl)-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione 1 (C₂₃H₂₅Cl₂NO₂, Mr = 418.34) and 3,3,6,6-tetramethyl-9,10-di(4-methoxy-phenyl)-3,4,6,7,9,10-hexahydro-2H,5H-acridine-1,8-dione 2 (C₃₁H₃₅NO₄, Mr = 485.60) were synthesized and crystallized. The crystals of compound 1 are monoclinic, space group P2₁/c, a = 9.826(3), b = 19.866(5), c = 11.471(3) ?, β = 111.929(4)°, Z = 4, V = 2077(1) ?³; The compound 2 crystallizes in space group P2₁/c, with cell parameters a = 12.089(2), b = 11.447(2), c = 19.742(3) ?, β = 101.00(1)°, V = 2681.8(8) ?³ and D _calc = 1.203 g/cm³ for Z = 4. X-ray analysis reveals that atoms C(1), C(6), C(7), C(8), C(13) and N(1) form a 1,4-dihydropyridine ring in compound 1, which adopts half-chair conformation. In compound 2 the atoms C(1), C(6), C(7), C(8), C(13) and N form a 1,4-dihydropyridine ring which adopts boat conformation. In addition, the two outer six-membered rings display half-chair conformations in the crystal structures 1 and 2.     

Crystal structure of R[UO2(CH3COO)3] (R = NH 4+ , K+, or Cs+)

The single crystal structure of NH₄[UO₂(CH₃COO)₃] (I), K[UO₂(CH₃COO)₃] (II), and Cs[UO₂(CH₃COO)₃] (III) is studied by X-ray diffraction. I and II crystallize in the tetragonal crystal system. The crystal data are as follows: a = 13.6985(3) and c = 27.5678(14) ?, V = 5173.1(3) ?³, space group I4₁/a, Z = 16, and R = 0.023 for I; a = 13.8890(5) and c = 26.0839(18) ?, V = 5031.7(4) ?³, space group I4₁/a, Z = 16, and R = 0.037 for II. Crystals III are orthorhombic, a = 18.176(2), b = 13.119(2), and c = 22.088(4) ?, V = 5267(1)?³, space group Pbca, Z = 16, and R = 0.0424. In structures I–III, the uranium-containing structural units are represented by discrete mononuclear [UO₂(CH₃COO)₃]⁻ groups, which belong to the AB ₃⁰¹ (A = UO₂²⁺, B ⁰¹=CH₃COO⁻) crystal chemical group of uranyl complexes.     

Synthesis and Crystal Structure of the Salt [PPN+]2[Cu2I2Cl2]2−

Abstract The synthesis of the PPN (PPN=Ph₃P=N=PPh₃) salt of di-μ-iodo-dichlorocuprate (I) anion [Cu₂I₂Cl₂]²⁻ is described and the crystal and molecular structures of this compound are reported. It was found that the compound has the formula [PPN]₂[Cu₂I₂Cl₂]_0.7[Cu₂I₄]_0.3 (3). Compound 3 crystallizes in an orthorhombic crystal system, space group Pbca, with a = 19.654(3), b = 16.130(2), c = 20.108(3) ?, V = 6374.3(16) ?³ and Z = 4. The crystal contains 70% [Cu₂I₂Cl₂]²⁻ anions and 30% [Cu₂I₄]²⁻ anions. This was also confirmed by MSES spectroscopy. The anion [Cu₂I₂Cl₂]²⁻ is planar and the Cu atoms have a trigonal planar configuration. Graphical abstract Synthesis and Crystal Structure of the Salt [PPN ⁺ ] ₂ [Cu ₂ I ₂ Cl ₂ ] ²⁻ Andrey A. Yakovenko, Tatiana V. Timofeeva and Mikhail Yu. Antipin The title compound was synthesized and structurally investigated. The crystal contains 70% [Cu₂I₂Cl₂]²⁻ anions and 30% [Cu₂I₄]²⁻ anions. This was confirmed by MS ES spectroscopy.      

Crystal and molecular structure of Sr2( Edta ) · 5H2O, Sr2(H2 Edta )(HCO3)2 · 4H2O, and Sr2(H2 Edta )Cl2 · 5H2O strontium ethylenediaminetetraacetates

Three Sr²⁺ compounds with the Edta ⁴⁻ and H₂ Edta ²⁻ ligands—Sr₂(Edta) · 5H₂O (I), Sr₂(H₂ Edta)(HCO₃)₂ · 4H₂O (II), and Sr₂(H₂ Edta)Cl₂ · 5H₂O (III)—are synthesized, and their crystal structures are studied. In I, the Sr(1) atom is coordinated by the hexadentate Edta ⁴⁻ ligand following the 2N + 4O pattern and by two O atoms of the neighboring ligands, which affords the formation of zigzag chains. The Sr(2) atom forms bonds with O atoms of five water molecules and attaches itself to a chain via bonds with three O atoms of the Edta ⁴⁻ ligands. The Sr(1)-O and Sr(2)-O bond lengths fall in the ranges 2.520(2)–2.656(3) and 2.527(3)–2.683(2) ?, respectively. The Sr(1)-N bonds are 2.702(3) and 2.743(3) ? long. In II and III, the H₂ Edta ²⁻ anions have a centrosymmetric structure with the trans configuration of the planar ethylenediamine fragment. The N atoms are blocked by acid protons. In II, the environment of the Sr atom is formed by six O atoms of three H₂ Edta ligands, two O atoms of water molecules, and an O atom of the bicarbonate ion, which is disordered over two positions. In III, the environment of the Sr atom includes six O atoms of four H₂ Edta ²⁻ ligands and three O atoms of water molecules. The coordination number of the Sr atoms is equal to 8 + 1. In II and III, the main bonds fall in the ranges 2.534(3)–2.732(2) and 2.482(2)–2.746(3) ?, whereas the ninth bond is elongated to 2.937(3) and 3.055(3) ?, respectively. In II, all the structural elements are linked into wavy layers. The O-H…O interactions contribute to the stabilization of the layer and link neighboring layers. In III, hydrated Sr²⁺ cations and H₂ Edta ^– anions form a three-dimensional [Sr₂(H₂ Edta)(H₂O)₃] _n ²ⁿ⁺ framework. The Cl⁻ anions are fixed in channels of the framework by hydrogen bonds with four water molecules. In II and III, the N-H groups form four-center N-H…O₃ hydrogen bonds, which include one intermolecular and two intramolecular components. PACS numbers: 61.66.Hq Original Russian Text ? I.N. Polyakova, A.L. Poznyak, V.S. Sergienko, 2009, published in Kristallografiya, 2009, Vol. 54, No. 2, pp. 262–267.