Co-crystallized Water Molecules Research Articles

Carbon dioxide capture from air leading to bis-[N-(5-methyl-1H-pyrazol-3-yl-κN2)carbamato-κO]copper(II) tetra-hydrate.

A mononuclear square-planar CuII complex of (5-methyl-1H-pyrazol-3-yl)carbamate, [Cu(C5H6N3O2)2]·4H2O, was synthesized using a one-pot reaction from 5-methyl-3-pyrazolamine and copper(II) acetate in water under ambient conditions. The adsorption of carbon dioxide from air was facilitated by the addition of di-ethano-lamine to the reaction mixture. While di-ethano-lamine is not a component of the final product, it plays a pivotal role in the reaction by creating an alkaline environment, thereby enabling the adsorption of atmos-pheric carbon dioxide. The central copper(II) atom is in an (N2O2) square-planar coordination environment formed by two N atoms and two O atoms of two equivalent (5-methyl-1H-pyrazol-3-yl)carbamate ligands. Additionally, there are co-crystallized water mol-ecules within the crystal structure of this compound. These co-crystallized water mol-ecules are linked to the CuII mononuclear complex by O-H⋯O hydrogen bonds. According to Hirshfeld surface analysis, the most frequently observed weak inter-molecular inter-actions are H⋯O/O⋯H (33.6%), H⋯C/C⋯H (11.3%) and H⋯N/N⋯H (9.0%) contacts.

Structural and spectral studies of hydrated hexaamminecobalt(III)–hexafluororhenate(IV)

The crystal structure of the [Co(NH3)6]2[ReF6]3·3H2O (I) salt is reported. The salt crystallizes in the trigonal space group P31m with the following unit cell dimensions: a = 15.8714(4) Å, b = 15.8714(4) Å, and c = 9.8657(4) Å. The structure of (I) consists of [Co(NH3)6]3+ cations, [ReF6]2− anions, and co-crystallized water molecules which are linked by hydrogen bonding. In (I), independent [ReF6]2− anions and [Co(NH3)6]3+ cations octahedron are slightly distorted. Characteristic vibration bands of the [Co(NH3)6]3+ cation, [ReF6]2− anion as well as the co-crystallized H2O molecules are observed in the infrared spectra of (I). UV-Visible analyses in water showed that the absorption of the [Co(NH3)6]3+ cation predominate the spectra of (I).

Zwitterion coordination to configurationally flexibled10cations: synthesis and characterization of tetrakis(betaine) complexes of divalent Zn, Cd, and Hg

AbstractThed10ions MII(M = Zn, Cd, Hg) and four equivalents of the neutral zwitterion trimethylglycine (betaine, bet) aggregate to discrete six-coordinated cationic complexes. With nitrate as counter anions, solids of the composition [M(bet)4](NO3)2·H2O are obtained. Their structural characterization reveals close relationship: they crystallize in metrically similar unit cells adopting three different subgroups of a hypothetical aristotype. In all cases, the divalent cations exhibit a strongly distorted coordination sphere in which two betaine ligands bind with both carboxylato O atoms and the other two with only one oxygen to the cation. Non-coordinating O atoms of different betaine ligands act as hydrogen bond acceptors towards co-crystallized water molecules. At least for the Pearson-soft HgIIcations, this coordination is unexpected: to the best of our knowledge, HgIIcomplexes with four carboxylato ligands have not yet been characterized. Without the necessity for charge balancing, the composition of zwitterion complexes is dominated by steric requirements and possibly by competition with alternative dipole molecules such as solvent water.

Hexa-aqua-dodeca-μ2-iodido-octahedro-hexa-tantalum diiodide tetra-hydrate.

In the crystal structure of the cluster salt, [Ta6I12(H2O)6]I2·4H2O, the octa-hedral {Ta6} cluster core is μ2-coordinated by twelve iodido ligands (inner ligand sphere) whereas the six aqua ligands coordinate each at the six outer positions. The discrete, inversion-symmetric cluster complex is double-positively charged, and two iodide anions are present in the crystal structure as counter-ions. In addition, four water mol-ecules are co-crystallized. Hydrogen bonds between the cluster unit, the iodide anions and co-crystallized water mol-ecules stabilize the charge-assisted packing in the crystal structure.

Synthesis, spectral characterization and DFT calculations of novel Ag(I) π-coordination polymeric complexes based on N-allylmorpholine-4-carbothioamide

Two complexes of Ag(I) with the N-allylmorpholine-4-carbothioamide (HL) with general formula ([Ag(HL)NO3]·3H2O)n (1) and [Ag(HL)NO3]n (2) were synthesized and isolated in crystalline state. X-ray diffraction study of compounds showed that both complexes are coordination polymers which differ by coordination manners of nitrate anions and presence of cocrystallized water molecules. In solid state in both complexes the ligand molecules are coordinated in bridging mode by μ2-S atom and the CC double bond of the allyl moiety with formation of stable six-membered chelate metallocycles and 1D Ag–S–Ag polymeric chains. However dissolution of the complexes in DMSO leads to cleavage of polymeric chains as well as Ag-(CC) π-coordination bonds, as evidenced by the 1H and 13C NMR spectroscopy data. Crystallographic data have also revealed so-called “additional” coordination of Ag+ ions, which complements the “usual” coordination polyhedra of Ag+ expanding its coordination numbers from 3 to 5 and 6, leading to stabilization of such compounds in solid state. Results of DFT calculation of IR spectra were compared with experimental data and fragmentation of complexes was investigated by MALDI-TOF mass spectrometry and TPD MS methods.

A new non-centrosymmetric Chlorobismuthate(III) hybrid material: Crystal structure, optical properties and antibacterial study

As part of our interest in organic-inorganic metallate complexes, we had prepared a novel non-centrosymmetric chlorobismuthate (III) compound with the chemical formula (C6H7NCl)3 [BiCl6]·H2O, by slow evaporation method at room temperature. It was characterized by single crystal X-ray diffraction (SCXRD), X-ray powder diffraction (PXRD), spectroscopic measurements, thermal study, Hirshfeld surface analysis, DFT investigation, and antimicrobial activity. A preliminary SCXRD structural analysis revealed that the compound crystallizes in the Orthorhombic system (P212121 space group) with the following unit cell parameters a = 7.3432 (1) Å, b = 13.8257 (2) Å and c = 28.2140 (5) Å with Z = 4 and V = 2864.42 (8) Å3. The examination of the structure shows that its atomic arrangement can be described as inorganic [BiCl6]3- units isolated from each other by the organic cations and the co-crystallized water molecules. The cohesion between these entities is performed via the NH⋯Cl, NH⋯O, CH⋯O, CH⋯Cl, and OH⋯Cl hydrogen bonding interactions between the 4-dichloroanilinium cations, the [BiCl6]3- anions and water molecules forming a 3D network. The Hirshfeld surface calculation was conducted to investigate: intermolecular interactions, associated 2D fingerprint plots, and enrichment ratio, indicating the relative contribution of these interactions in the crystal structure quantitatively. Thermal analysis reveals the decomposition of the compound at 180 °C. The quantum mechanical calculations such as geometry optimization, vibrational frequencies, simulated UV–Visible spectrum, FMOs analysis were made together with the experimental studies. Furthermore, the new synthesized compound was screened for its antibacterial activity. Results revealed that it has the most effective activity against all the tested bacteria compared to the amine alone and to the BiOCl.

Synthesis and Crystal Structures of Ethyl 2-(4-Methoxyphenyl)-1H-benzo[d]imidazole-5-carboxylate Dihydrate and Its Building Block 4-Fluoro-3-nitrobenzoic Acid

The title compound, ethyl 2-(4-methoxyphenyl)-1H-benzo[d]imidazole-5-carboxylate dihydrate (5), was synthesized and its crystal structure was studied by single-crystal X-ray diffraction technique. Compound 5 is crystallized in the centrosymmetric triclinic space group $$P\bar {1}$$ with Z = 4 and Z′ = 2, and unit-cell parameters of a = 8.9190 (3) A, b = 12.6888 (4) A, c = 14.7111 (5) A, α = 98.4855 (10)°, β = 101.6379 (9)°, γ = 95.4346 (10)° and V = 1599.43 (9) A3. Its starting material, 4-fluoro-3-nitrobenzoic acid (1), is crystallized in the non-centrosymmetric monoclinic space group P21 and Z = 4 with unit-cell parameters of a = 3.7170 (4) A, b = 12.6475 (13) A, c = 15.5237 (15) A, α = 90°, β = 91.9786 (16)°, γ = 90° and V = 729.35 (13) A3. It was noted that strong hydrogen bonds play important roles in the crystal packing of both compounds, especially in 5, in which the co-crystallized water molecules act as both strong hydrogen bond donor and strong hydrogen bond acceptor. Two molecule of compound 5 crystallized in a non symmetrical manner with four co-crystallized water molecules which play an important role in the crystal packing as strong hydrogen-bond donors.

Dimorphism of Hexaaquanickel(Ii) Bis(p-Nitrobenzoate) Dihydrate Salt: A New Triclinic Crystal Form

Room temperature crystallization from a water/ethanol solution of NiSO4, p-nitrobenzoic acid (HPNBA), and thiourea yields single crystals of [Ni(H2O)6](PNBA)2·2H2O. Crystal data are: a = 5.9626(8), b = 7.3552(11), c = 12.3459(17) A, α = 97.885(12), β = 96.714(11), γ = 91.158(11)°, V = 532.28(13) A3, space group Pī, Z = 1. An alternative monoclinic crystal form of the same compound with a slightly lower packing efficiency was previously obtained. The Ni(II) cation is located on a crystallographic inversion center and octahedrally coordinated by six water molecules. The PNBA moieties occupy an outer coordination sphere acting as counter-anions. An intricate system of H bonds between the complex cation, the PNBA anions, and the co-crystallized water molecules results in a three-dimensional network.

Molecular and crystal structure and the Hirshfeld surface analysis of 1-amino-1-deoxy-α-d-sorbopyranose and 1-amino-1-deoxy-α-d-psicopyranose (“d-sorbosamine” and “d-psicosamine”) derivatives

Sorbosamine and psicosamine are the last two 1-amino-1-deoxy-hexuloses for which no structural data were available. We report on a13C NMR and a single crystal X-ray diffraction study of 1-deoxy-1-(N-methylphenylamino)-d-sorbose (1) and 1-deoxy-1-(N-methylphenylamino)-d-psicose (2). In solutions, both aminosugars are conformationally unstable and establish equilibria, with 90.7% α-pyranose, 3.8% α-furanose, 1.0% β-pyranose, 0.5% β-furanose, and 4.0% acyclic keto form for 1 and 32.4% α-furanose, 27.2% α-pyranose, 21.0% β-pyranose, 9.1% β-furanose, and 11.0% acyclic keto form for 2. X-ray diffraction data provided detailed structural information on 1 and 2 in the α-pyranose form. Both molecules adopt the 5C2 ring conformations, the bond distances and valence angles compare well with respective pyranose structures. All hydroxyl groups in crystal structures of both 1 and 2 participate in two-dimensional hydrogen bonding networks, the H-bonding pattern in 1 is dominated by co-crystallized water molecules. The Hirshfeld surface analysis revealed a significant contribution of non- or weakly polar interactions to the packing forces for both molecules, with crystal structure of 2 featuring short H⋯H contacts. Other structural features found in 2 are a significant planarity of the tertiary amino group (the pyramid heights are 0.127 Å in 2 vs 0.231 Å in 1), a concomitant non-involvement of the amine nitrogen in heteroatom contacts, and a unique anti-periplanar conformation around the C1C2 bond.

The ephemeral dihydrate of sulfanilic acid

Evaporation of an aqueous solution of sulfanilic acid (systematic name: 4-aminobenzene-1-sulfonic acid) at 273 K affords a crystalline dihydrate, C6H7NO3S·2H2O. The organic molecule exists as a zwitterion; two zwitterions are aligned in an antiparallel fashion about a crystallographic centre of inversion. They interact directly via two N-H...O hydrogen bonds between the ammonium group of one zwitterion and the sulfonate group of its symmetry-related counterpart, and their aromatic rings are π-stacked, with an interplanar distance of 3.533 (3) Å. One of the cocrystallized water molecules connects the resulting pairs into layers and the second crosslinks the layers into a three-dimensional network. All H atoms connected to N or O atoms find acceptors in suitable geometries. In the resulting crystal, polar and hydrogen-bond-dominated slabs alternate with stacks of organic arene rings. Although the new dihydrate shows efficient space filling, with a packing coefficient of 75.7%, it is unstable and undergoes fast desolvation at room temperature. In this process, the orthorhombic ansolvate forms as a pure phase.

Dimorphism of hexaaquanickel(II) bis(p-nitrobenzoate) dihydrate salt: A new triclinic crystal form

Room temperature crystallization from a water/ethanol solution of NiSO4, p-nitrobenzoic acid (HPNBA), and thiourea yields single crystals of [Ni(H2O)6](PNBA)2·2H2O. Crystal data are: a = 5.9626(8), b = 7.3552(11), c = 12.3459(17) Å, α = 97.885(12), β = 96.714(11), γ = 91.158(11)°, V = 532.28(13) Å3, space group P1̅, Z = 1. An alternative monoclinic crystal form of the same compound with a slightly lower packing efficiency was previously obtained. The Ni(II) cation is located on a crystallographic inversion center and octahedrally coordinated by six water molecules. The PNBA moieties occupy an outer coordination sphere acting as counter-anions. An intricate system of H bonds between the complex cation, the PNBA anions, and the co-crystallized water molecules results in a three-dimensional network.

Iodide and triiodide anion complexes involving anion-π interactions with a tetrazine-based receptor.

Protonated forms of the tetrazine ligand L2 (3,6-bis(morpholin-4-ylethyl)-1,2,4,5-tetrazine) interact with iodide in aqueous solution forming relatively stable complexes (ΔG° = -11.6(4) kJ mol-1 for HL2+ + I- = (HL2)I and ΔG° = -13.4(2) kJ mol-1 for H2L22+ + I- = [(H2L2)I]+). When solutions of [(H2L2)I]+ are left in contact with air, crystals of the oxidation product (H2L2)2(I3)3I·4H2O are formed. Unfortunately, the low solubility of I3- complexes prevents the determination of their stability constants. The crystal structures of H2L2I2·H2O (1), H2L2(I3)2·2H2O (2) and (H2L2)2(I3)3I·4H2O (3) were determined by means of X-ray diffraction analyses. In all crystal structures, it was found that the interaction between I- and I3- with H2L22+ is dominated by anion interactions with the π electron density of the receptor. Only in the case of 1, the iodide anions involved in close anion-π interactions with the ligand tetrazine ring form an additional H-bond with the protonated morpholine nitrogen of an adjacent ligand molecule. Conversely, in crystals of 2 and 3 there are alternate segregated planes which contain only protonated ligands hydrogen-bonded to cocrystallized water molecules or I3- and I- forming infinite two-dimensional networks established through short interhalogen contacts, making these crystalline products good candidates to behave as solid conductors. In the solid complexes, the triiodide anion displays both end-on and side-on interaction modes with the tetrazine ring, in agreement with density functional theory calculations indicating a preference for the alignment of the I3- molecular axis with the molecular axis of the ligand. Further information about geometries and structures of triiodide anions in 2 and 3 was acquired by the analysis of their Raman spectra.

A Three-Dimensional Samarium Coordination Polymer with Benzene-1,2,4,5-tetracarboxylic Acid, Synthesis, Characterization and Thermal Decomposition to Sm2O3 Nanoparticles

A treatment of benzene-1,2,4,5-tetracarboxylic acid (btcH4) and pyridine-2,3-dicarboxylic acid (pydcH2) with Sm(NO3)3·6H2O led to the formation of a new three-dimentional samarium(III) coordination polymer (just with btcH4),{[Sm(btcH2)0.5(btc)0.5(H2O)]·2H2O}∞ (1). Compound 1 was characterized by infrared spectroscopy, elemental analyses as well as by X-ray diffraction studies. The results of the single-crystal X-ray diffraction analyses reveal that compound is a 3D coordination polymer. The polymeric network of 1 contains Sm(III) ions bridged by btcH2 2− and btc4− ions. Each four-dentate btcH22− ion is connected to four Sm3+ ions through the four oxygen atoms of two deprotonated carboxyl groups and btc4− is coordinated to six Sm3+ ions as tree-dentate coordination through the four carboxylate groups. btc4− is also connected to two additional Sm3+ ions through the oxygen atoms. Samarium(III) ion is nine coordinated by oxygen atoms of two different btcH2 2−, two btc4− ligands and one water molecule. Many hydrogen bonds of the O–H···O type are also present in the crystal structure of 1 and assemble the polymeric chains and the co-crystallized water molecules into a 3D architecture. The coordination polymer 1 was used for the preparation of the Sm2O3 nanoparticles. Synthesized Sm2O3 nanoparticles were characterized by infrared spectroscopy, powder X-ray diffraction (PXRD) and scanning electron microscopy. The body- centered cubic structure of Sm2O3 was determined by PXRD.

Crystal structures of coordination polymers from CaI2 and proline.

Completing our reports concerning the reaction products from calcium halides and the amino acid proline, two different solids were found for the reaction of l- and dl-proline with CaI2. The enanti-opure amino acid yields the one-dimensional coordination polymer catena-poly[[aqua-μ3-l-proline-tetra-μ2-l-proline-dicalcium] tetra-iodide 1.7-hydrate], {[Ca2(C5H9NO2)5(H2O)]I4·1.7H2O} n , (1), with two independent Ca(2+) cations in characteristic seven- and eightfold coordination. Five symmetry-independent zwitterionic l-proline mol-ecules bridge the metal sites into a cationic polymer. Racemic proline forms with Ca(2+) cations heterochiral chains of the one-dimensional polymer catena-poly[[di-aquadi-μ2-dl-proline-calcium] diiodide], {[Ca(C5H9NO2)2(H2O)2]I2} n , (2). The centrosymmetric structure is built by one Ca(2+) cation that is bridged towards its symmetry equivalents by two zwitterionic proline mol-ecules. In both structures, the iodide ions remain non-coordinating and hydrogen bonds are formed between these counter-anions, the amino groups, coordinating and co-crystallized water mol-ecules. While the overall composition of (1) and (2) is in line with other structures from calcium halides and amino acids, the diversity of the carboxyl-ate coordination geometry is quite surprising.

Luminescent zinc aliphatic dicarboxylate coordination polymers with bis(4-pyridylmethyl)piperazine: Effect of chain length and steric bulk on topology and water molecule aggregation

Hydrothermal reaction of zinc nitrate, aliphatic dicarboxylic acids, and the long-spanning hydrogen-bonding capable tethering ligand bis(4-pyridylmethyl)piperazine (4-bpmp) has produced seven coordination polymer solids that were characterized via single-crystal X-ray crystallography. [Zn(suc)(4-bpmp)(H2O)2]n (1, suc=succinate) shows 2D+2D→3D mutually inclined interpenetrated parallel coordination polymer layers with (4,4) grid topology. {[Zn2(dms)2(4-bpmp)]·2H2O}n (2, dms=2,2-dimethylsuccinate) exhibits 1-D [Zn2(dms)2]n ribbons featuring {Zn2(OCO)2} dimeric units pillared into 2-D by 4-bpmp ligands. {[Zn(glu)(4-bpmp)]·6H2O}n (3, glu=glutarate) manifests a 3-fold interpenetrated 3-D 66 diamondoid topology with embedded C(10)A(4) water chains. [Zn(22dmg)(4-bpmp)]n (4, 22dmg=2,2-dimethylglutarate) and [Zn(33dmg)(4-bpmp)]n (5, 33dmg=3,3-dimethylglutarate) both display stacked zig–zag (4,4) grid layered topologies, and do not entrain any co-crystallized water molecules. Reduction of the steric hindrance by using 3-methylglutarate (3mg) afforded {[Zn(3mg)(4-bpmp)]·3H2O}n (6), which also displays a (4,4) grid topology, but with embedded R(4)A(2) water molecule hexamers connecting to three different layer motifs. [Zn(adp)(4-bpmp)]n (7, adp=adipate) possesses a system of 5-fold interpenetrated diamondoid nets. Thermal and luminescent properties of these materials are discussed herein.

Physico-Chemical Studies of Tris (adamantan-1-aminium) Hexachlorostannate (IV) Chloride Monohydrate

The structural characteristics of organic ammonium salts of the hexahalogenostannates (IV) with a general formula (R-NH 3)3SnX 6 have not yet been studied extensively. In the course of investigating these types of materials, the title compound, a double salt of adamantan-1aminium chloride and hexahalogenostannate (IV), with the formula (C 10 H18 N) 3[SnCl 6]Cl·H 2O, was crystallized. Its asymmetric unit contains three independent cations of protonated adamantan-1-amine, one chloride anion, one Hexachlorostannate (IV) ion and a hydrate water molecule. The atomic arrangement can be described as inorganic SnCl 6 2- units isolated from each other by the organic cations, the chloride anions and the cocrystallized water molecules. The compound exhibits bifurcated and simple hydrogenbonding interactions between the ammonium groups, the water molecules and the chlorine atoms, with little variation in the hydrogen-bonding interactions. The 119 Sn, 13 C and 15 N CPMAS NMR spectra are in agreement with the X-ray structure.

Influence of nitrogen donor ligands on the coordination modes of copper(ii) 2-nitrobenzoate complexes: structures, DFT calculations and magnetic properties

Three novel copper(II) 2-nitrobenzoate complexes, [Cu(γ-pic)2(2-nitrobenzoate)2] 1, [Cu(β-pic)2(2-nitrobenzoate)2(H2O)2] 2 and [Cu2(H2tea)2(2-nitrobenzoate)2]·2(H2O) 3 (where γ-pic = 4-methylpyridine, β-pic = 3-methylpyridine and H2tea = mono deprotonated triethanolamine), were isolated by addition of γ-pic, β-pic and H3tea to the hydrated copper(II) 2-nitrobenzoate, [Cu2(2-nitrobenzoate)4(H2O)2]·2H2O, suspended in a methanol : water (4 : 1) mixture. The newly synthesized complexes have been characterized by elemental analyses, thermogravimetric analysis (TGA), spectroscopic techniques (EPR, IR and UV/Visible), magnetic susceptibility measurements, single crystal X-ray structure determination and DFT study. All compounds crystallize in the monoclinic crystal system with the P21/c space group. X-ray structure determination revealed the presence of monomers in both 1 and 2 and dimer in 3 with the deprotonated oxygen atom of the H2tea ligand bridging two Cu(II) atoms. Two co-crystallized water molecules are also present in 3. The crystal lattice is stabilized by C–H⋯O hydrogen bonding interactions in 1 and O–H⋯O, C–H⋯O hydrogen bonding interactions in 2 and 3. The dimeric complex exhibits relatively strong ferromagnetic exchange with J = −100 cm−1 (corresponding to H = JS1S2). The zero-field splitting parameters (zfs) of the dimer triplet states D and E were derived from HF EPR spectra recorded at moderately low temperatures. The sign of D was determined from low-temperature HF EPR spectra.

N-(L-2-Aminopentanoyl)-L-phenylalanine dihydrate, a hydrophobic dipeptide with a nonproteinogenic residue

The title dipeptide, better known as L-norvalyl-L-phenylalanine {systematic name: (S)-2-[(S)-2-aminopentanamido]-3-phenylpropanoic acid dihydrate}, C14H20N2O3·2H2O, has a nonproteinogenic N-terminal residue. In the solid state, it takes on a molecular conformation typical for one of the three classes of nanoporous dipeptides, but like two related compounds with a hydrophobic N-terminal residue and a C-terminal L-phenylalanine, it fails to form channels or pores. Instead, the crystal structure is divided into distinct hydrophobic and hydrophilic layers, the latter encompassing cocrystallized water molecules connecting the charged N- and C-terminal groups.

Supramolecular 1D ribbons in complexes between a bicyclic-guanidine derivative and di- or monocarboxylic acids

Zwitterionic crystalline complexes between 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), a guanidine derivative, and two dicarboxylic acids (DCAs) (oxalic acid, adipic acid) as well as a special monocarboxylic acid (glycolic acid) have been analyzed by single crystal X-ray diffraction methods. In the solid state the carboxylic acid forms a monoanion by readily transferring an acidic proton to a TBD base, resulting in formation of strong +N–H⋯O− hydrogen-bonded R22(8) ring motifs, while O–H⋯O interactions expand the network into infinite one-dimensional supramolecular chains. Numerous C(sp3)–H⋯O interactions also contribute in crystal packing, including TBD as a weak donor and O atoms of carboxyl groups or co-crystallized water molecules as acceptors. The hydrogen bonding and crystal packing of all three complexes have been compared with the respective guanidine–carboxylate or related complexes reported previously.

The cerium(III) coordination polymer with mixed polycarboxylic acids. Preparation of the CeO2 nanoparticles by thermal decomposition of the polymer

A treatment of benzene-1,2,4,5-tetracarboxylic acid (H4btc) and pyridine-2,6-dicarboxylic acid (H2pydc) with Ce(NO3)3·6H2O (in the molar ratio 1:1:2) under hydrothermal conditions led to the formation of a new 1D cerium(III) coordination polymer {[(pydc)2Ce2(μ-H2btc)(H2O)6]·4H2O}n (1). Compound 1 was characterized by infrared spectroscopy, elemental analyses and by X-ray diffraction studies. The polymeric chain of 1 contains cerium(III) ions bridged by H2btc2− ligand. Each H2btc2− ion is connected to four cerium(III) ions via its two bidentate and bridging carboxylate groups. Cerium(III) ion is nine-coordinated by three oxygen atoms from two different H2btc2− ligands, two oxygen atoms and one nitrogen atom from the tridentate pydc2− ligand and three coordinated water molecules, resulting with a distorted tricapped trigonal prismatic arrangement. Many hydrogen bonds of the O–H⋯O type are also present in the crystal structure of 1 and assemble the polymeric chains and the co-crystallized water molecules into a 3D architecture. The coordination polymer 1 was used for the preparation of the CeO2 nanoparticles. Synthesized CeO2 nanoparticles were characterized by infrared spectroscopy, powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). The face-centered cubic structure of CeO2 was determined by PXRD.