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A new coordination polymer, poly[(acetato)aqua(μ3-phthalato)europium(III)], [Eu(C8H4O4)(CH3O2)(H2O)] n or [EuIII(phth)(OAc)(H2O)] (phth2− = phthalate and OAc− = acetate) was synthesized and characterized, revealing it to be a supramolecular assembly of one-dimensional [EuIII(phth)(OAc)(H2O)] chains. Each chain is built up of edge-sharing distorted tricapped trigonal–prismatic TPRS-{EuIIIO9} building motifs and assembled in a regular fashion through hydrogen-bonding and aromatic π–π interactions. The fully deprotonated phth2− ligand was shown to be an effective sensitizer, promoting the characteristic 5 D 0→7 FJ (J = 1–4) emissions of EuIII even in the presence of the non-sensitizing OAc− group.

The inclusion of α-cyclodextrin and both α- and γ-cyclodextrins in a multilayer framework composed of d-penicillaminato AuI3CoIII2 complex anions and aqua sodium(i) cations via solvent-mediated structural transformations are reported.

Treatment of Na3[Au3Co2(d-pen)6] (Na3[1]; d-H2pen = d-penicillamine) with M(OAc)2 (M = NiII, MnII) in water gave ionic crystals of [M(H2O)6]3[1]2 (2M) in which [1]3- anions are hydrogen-bonded with [M(H2O)6]2+ cations to form a 3D porous framework with a porosity of ca. 80%. Soaking crystals of 2Ni in its mother liquor afforded crystals of [Ni(H2O)6]2[{Ni(H2O)4}(1)2] (3Ni) in which [1]3- anions are connected to trans-[Ni(H2O)4]2+ and [Ni(H2O)6]2+ cations through coordination and hydrogen bonds, respectively, to form a 1D porous framework with a porosity ca. 60%. Further soaking crystals led to [{Ni(H2O)4}3(1)2] (4Ni), in which [1]3- anions are connected to cis-[Ni(H2O)4]2+ and trans-[Ni(H2O)4]2+ cations through coordination bonds in a dense framework with a porosity of ca. 30%. A similar two-step crystal-to-crystal transformation mediated by solvent proceeded when crystals of 2Mn were soaked in a mother liquor. However, the transformation of 2Mn generated [{Mn(H2O)4}(H1)] (4'Mn) as the final product, in which [H1]2- anions are connected to cis-[Mn(H2O)4]2+ cations through coordination bonds in a very dense framework with a porosity ca. 5% by way of [Mn(H2O)6]2[{Mn(H2O)4}(1)2] (3Mn), which is isostructural with 3Ni. While all the compounds adsorbed H2O and CO2 depending on the degree of their porosity, unusually large NH3 adsorption capacities were observed for 4Ni and 4'Mn, which have dense frameworks.

Inspired by the catalytic potential of lanthanide coordination polymers of 3,3',5,5'-azobenzenetetracarboxylic acid (H

Reactions of [Au2(dppe)(d-Hpen)2] (dppe = 1,2-bis(diphenylphosphino)ethane, d-H2pen = d-penicillamine) with M(NO3)3 (M = GaIII, InIII) afforded charge-separation-type ionic solids, [Au4M2(dppe)2(d-...

To compare efficiency of disulfide and thiol groups in removing mercury from aqueous medium without noteworthy influence from structural differences, a series of new [Ln

A new coordination polymer, poly[(acetato)aqua(μ

Treatment of Na

The crystal structures of five new transition-metal complexes synthesized using thiazole-2-carboxylic acid (2-Htza), imidazole-2-carboxylic acid (2-H2ima) or 1,3-oxazole-4-carboxylic acid (4-Hoxa), namely diaquabis(thiazole-2-carboxylato-κ2 N,O)cobalt(II), [Co(C4H2NO2S)2(H2O)2], 1, diaquabis(thiazole-2-carboxylato-κ2 N,O)nickel(II), [Ni(C4H2NO2S)2(H2O)2], 2, diaquabis(thiazole-2-carboxylato-κ2 N,O)cadmium(II), [Cd(C4H2NO2S)2(H2O)2], 3, diaquabis(1H-imidazole-2-carboxylato-κ2 N 3,O)cobalt(II), [Co(C4H2N2O2)2(H2O)2], 4, and diaquabis(1,3-oxazole-4-carboxylato-κ2 N,O 4)cobalt(II), [Co(C4H2NO3)2(H2O)2], 5, are reported. The influence of the nature of the heteroatom and the position of the carboxyl group in relation to the heteroatom on the self-assembly process are discussed based upon Hirshfeld surface analysis and used to explain the observed differences in the single-crystal structures and the supramolecular frameworks and topologies of complexes 1–5.

A series of monometallic [Ln2(BDC)3(DMF)2(H2O)2]n (Ln = EuIII, GdIII, TbIII; H2BDC = benzene-1,4-dicarboxylic acid; DMF = dimethylformamide) and the lanthanide luminophores-loaded [LnxGd2-x(BDC)3(DMF)2(H2O)2]n (Ln = EuIII and TbIII) were synthesized and used in photoluminescent study. The dependence of emitting colors of [LnxGd2-x(BDC)3(DMF)2(H2O)2]n on the luminophore contents is reported and discussed based on the sensitization efficiency of BDC2− antenna. On the basis of an explicit change in the emitting colors of [EuxGd2-x(BDC)3(DMF)2(H2O)2]n, colorimetric analysis has been introduced as a new and effective strategy to establish ratiometric-thermometric parameters. Within the sRGB and CIE XYZ color matching systems, the temperature-dependent ratiometric-thermometric parameters could be derived from both x/(x+y) and R/(R+G) over 303–348 K covering physiological temperatures. Temperature resolution in term of standard deviation of the measurements, repeatability and relative sensitivity of the successive measurements have been evaluated and are reported.

Crude water extract of the ground longan seeds which have been disposed in a large amount annually in Northern Thailand has been used in a simple and rapid microwave synthesis of ZnO nanoparticles. The particles were characterized by the UV-vis spectroscopy, Fourier-transformed infrared spectroscopy, X-ray diffraction, electron diffraction, energy dispersive X-ray spectroscopy, and transmission electron microscopy and revealed to be pure hexagonal phase. Influences of zinc precursor in the extract, microwave power, and irradiation time on particle sizes were studied. The use of 800 W and 30 cycles of the microwave irradiation provided the ZnO particles of 10–100 nm in size with an active surface area, a band gap energy, and a zero-point charge of 35 m2·g−1, 3.42 eV, and pH 7.7, respectively, after the calcination. Photocatalytic efficiencies of the synthesized particles were evaluated through the decolorization of methylene blue, malachite green, methyl orange, and orange II, and proved to be on par with commercially available titanium dioxide (Arroxide®P-25) under the same conditions. The use of the longan seeds biowaste as a sustainable supply of natural reagents for the green synthesis of ZnO nanoparticles which can be employed further for waste water treatment of the local textile dyeing industry is therefore presented.

The AgI ion is coordinated by two heterocyclic N atoms from two ligands in a linear configuration, forming a discrete coordination complex. There is an O—H⋯O hydrogen bond between 2-tza− and 2tzaH of adjacent complexes. The hydrogen atom is shared between the two oxygen atoms., The linear two-coordinate silver (I) complex [Ag(C4H2NO2S)(C4H3NO2S)] or [Ag(2-Htza)(2-tza)] is reported (2-Htza = 1,3-thia­zole-2-carb­oxy­lic acid). The AgI ion is coordinated by two heterocyclic N atoms from two ligands in a linear configuration, forming a discrete coordination complex. There is an O—H⋯O hydrogen bond between 2-tza− and 2tzaH of adjacent complexes. The hydrogen atom is shared between the two oxygen atoms. This inter­action produces a hydrogen-bonded tape parallel to the [110] direction, which is augmented through inter­molecular C—H⋯O hydrogen-bonding inter­actions between the bound thia­zole groups. There is a further rather long Ag⋯O inter­action [2.8401 (13) Å, compared with a mean of 2.54 (11) Å for 23 structures in the CSD] that assembles these tapes into columns, between which there are C—H⋯π inter­actions, leading to the formation of a three-dimensional supra­molecular architecture.

A new series of two-dimensional [LnIII(abdc)0.5(phth)(H2O)2]∙2H2O coordination frameworks, where LnIII = EuIII (I), GdIII (II), TbIII (III), abdc2− = trans-azobenzene-4,4ʹ-dicarboxylate, and phth2− = phthalate, were designed, synthesized and characterized. According to the single crystal data and powder X-ray diffraction, I-III are isostructural and composed of the two-dimensional [LnIII(abdc)0.5(phth)(H2O)2] layers built up of the one-dimensional [LnIII(phth)(H2O)2] ladders and abdc2− linkers. Similarity in layer registry and identical topology to the other coordination polymers of phth2− are presented, from which the successful implementation of reticular concept is illustrated. Correlation between the framework structures and thermal stability as well as the N2 and CO2 sorption/desorption behaviors are included. Solid state photoluminescence of I - III were then investigated manifesting the substantial influence of abdc2− on the completely silent emission of I - III through the phth2−-to-abdc2− energy transfer.

The new nanoporous framework [Gd4(di-nitro-BPDC)4(NO2)3(OH)(H2O)5]·(solvent) (I; di-nitro-BPDC2– = 2,2′-dinitrobiphenyl-4,4′-dicarboxylate) has been designed and synthesized through a simple one-po...

A new series of non-porous, three-dimensional coordination frameworks, i.e. [LnIII(bdc)0.5(phth)(H2O)2], where LnIII = EuIII, TbIII, HoIII, ErIII and TmIII, phth2- = 1,2-benzenedicarboxylate, and bdc2- = 1,4-benzenedicarboxylate, were synthesized and characterized. The frameworks have two-dimensional sheets of which the stoichiometry is the same as the framework containing only phth2-. Architecture, topology and thermal stability of the frameworks were examined. Temperature-dependent photoluminescent properties of the EuIII and TbIII frameworks were studied and discussed with reference to those containing only phth2- and bdc2-. The mixed EuIII/TbIII frameworks were also prepared and their temperature-dependent photoluminescent properties were investigated, revealing energy transfer from TbIII to EuIII and its dependence on EuIII content.

An unsaturated Mn(II)-centered metal-organic framework was synthesized. The presence of an unsaturated Mn(II) center, together with a guest-responsive structural changing feature, plays a crucial role for strong binding with water, leading to its potential application for water/ethanol separation. In addition, the present framework is thermally stable up to 400 °C, which is beneficial for the regeneration process after adsorption.

A facile phytosynthesis of Ag/AgCl and Ag nanoparticles (NPs) was developed using a crude water extract of Citrus hystrix DC (kaffir lime) leaves. The phytochemical and chloride contents of the extract, and various synthesis parameters were studied. The obtained Ag/AgCl and Ag NPs were of the cubic phase and mostly spherical in shape. Particle sizes of the yielded NPs were distributed in a narrow range with an average size of 20 and 38 nm for the Ag/AgCl and Ag NPs, respectively. The reducing function of the phytochemicals and the stabilizing ability of gelatin were demonstrated. The NPs showed significant anti-proliferative activities against the carcinoma HCT 116 and adenocarcinoma Caco-2 colorectal cell lines, but had a negative effect toward human fibroblasts. The NPs exhibited excellent antibacterial activities against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus. The inactivation kinetics obtained in the presence of the NPs showed a biphasic behavior that can be explained by the Cerf model.

The isostructural [Ln(L)0.5(NO2-BDC)(H2O)]·3H2O complexes (Ln = EuIII (I), TbIII (II), GdIII (III) and 0.012EuIII/0.494TbIII/0.494GdIII (IV); L = BDC2− or BDC2−/NO2-BDC2−; H2BDC = 1,4-benzenedicarboxylic acid) were synthesized and characterized by powder X-ray diffraction and wavelength dispersive X-ray fluorescence. Room temperature and temperature dependent photoluminescence behavior of the title complexes were studied in solid state using the ground crystals. The rare constant intensity of EuIII with increasing temperatures in complex I is reported, and a potential of the mixed complex IV as a ratiometric luminescence thermometer in a temperature range 333(2)–423(2) K is illustrated.

A series of nanoporous [LnIII4(di-nitro-BPDC)4(NO2)3(OH)(H2O)5]·n(methanol) (LnIII ​= ​PrIII, NdIII, SmIII, EuIII, GdIII, PrIII/GdIII and PrIII/EuIII; di-nitro-BPDC2- ​= ​2,2′-dinitrobiphenyl-4,4′-dicarboxylate) was synthesized and characterized. Founded on Lewis acidic LnIII possessing vacant coordination sites and functional groups of di-nitro-BPDC2-, their catalytic activities were evaluated based on the CO2 cycloaddition reactions with epoxides under ambient pressure and solvent-free conditions. Depending on catalytic conditions, satisfying turnover number and turnover frequency of 1106 and 276 h-1, respectively, could be yielded with ≥79(±4)% conversion and 87(±1)% selectivity. The correlation between the catalysis performance and structural factors is proposed on a basis of experimental and computation results. These include the restrained transportation even in the nanoporous framework and crystallographic disorder in the LnIII coordination environment. The excellent robustness of the catalysts, effects of lanthanide contraction, and synergistic activities of the heterometallic PrIII/GdIII and PrIII/EuIII catalysts are also included.

Six new lanthanide metal organic complexes, i.e. [La2(NO2-BDC)3(H2O)4] (1) [Ln(L)0.5(NO2-BDC) (H2O)]·3H2O (Ln = Eu (2), Tb (3), Dy (4) and Ho (5); L = BDC2− or BDC2−/NO2-BDC2-) and [Tm(NO2-BDC)1.5(H2O)]·H2O (6), have been synthesized using mixed ligands of benzene-1,4-dicarboxylic acid (H2BDC) and the in situ generated 2-nitro-benzene-1,4-dicarboxylic acid (NO2-BDC2-). Single crystal structures and topologies of the complexes are presented based on the single crystal X-ray diffraction and spectroscopic data. Whilst the structures of 1 and 6 contain negligible voids, the frameworks of 2–5 are microporous in nature and stable upon the removal of all the water molecules from the structures and thermal treatment to over 400 °C. Based on the study of 2, significant adsorption capacities for carbon dioxide (95 cm3·g−1 or 4.2 mmol·g−1) and hydrogen (79 cm3·g−1 or 4 mmol·g−1), as well as the remarkable stability of the framework upon the sorption/desorption experiments are revealed.

Ten lanthanide coordination polymers were designed and synthesized using pyridine-2,6-dicarboxylic acid (H2pdc) and two different heating techniques (conventional and microwave): [Ln(pdc)(H2O)4]3·3Cl {Pa3; Ln = Pr (I), Nd (II), Sm (III), Eu (IV), and Gd (V)}, [Ln(pdc)(Hpdc)(H2O)2]·3H2O {P21/c; Ln = Pr (VI), Nd (VII), and Sm (VIII)} and [Ln(pdc)(H2O)4]3·3Cl {Ia3; Ln = Sm (IX), and Eu (X)}. These complexes show variation in structures depending on the heating technique and the lanthanide ions. They can be classified into the cubic Pa3 (I–V) and Ia3 (IX, X), and the monoclinic P21/c (VI–VIII) complexes. The cubic complexes exhibit supramolecular isomerism and a tubular three-dimensional structure of interpenetrated lcs and pcu net topologies, while the monoclinic complexes are the supramolecular assemblies of the one-dimensional chains. As the cubic Pa3 structures are favored by the use of the microwave, there is variation in structures as conventional heating was employed, although the cubic Pa3 struc...

We have successfully prepared crystals of thiazole-5-carboxylic acid (5-Htza) (L) and three new thiazole-5-carboxylate-based Cu2+ coordination polymers with different dimensionality, namely, 1D [Cu2(5-tza)2(1,10-phenanthroline)2(NO3)2] (1), 2D [Cu(5-tza)2(MeOH)2] (2), and 3D [Cu(5-tza)2]·H2O (3). These have been characterized by single crystal X-ray diffraction and thermogravimetry. Interestingly, the 2D network structure of 2 can directly transform into the 3D framework of 3 upon removal of methanol molecules at room temperature. 2 can also undergo structural transformation to produce the same 2D network present in the known [Cu(5-tza)2]·1.5H2O upon heat treatment for 2 h. This 2D network can adsorb water and convert to 3 upon exposure to air.

A green, rapid, simple and reliable procedure was developed for nitrite determination using silver-miang nanocomposites as colorimetric agents and camera phone as a detector. The crude water extracts of miang (Camellia sinensis var. assamica) were adopted as natural reagents in a rapid one-pot microwave synthesis of the nanocomposites. The extracts’ phytochemical contents were studied and the synthesis conditions were optimized. The yielded nanocomposites were characterized by UV–vis and FT-IR spectroscopies, powder X-ray diffraction, transmission electron microscopy, selected area electron diffraction and thermogravimetry, and proved to be reliable colorimetric agents and selective for nitrite. The underlying reactions were investigated. The linear calibration plots could be established based on the ratiometric R/G parameters over 2.0–10 mg∙L−1 nitrite concentration range with satisfying detection limits (0.12–0.62 mg∙L−1). In practice, the procedure was validated and applied with water and commercialized meat samples. The long storage time of miang (>5 years) was also evaluated, manifesting viability and reliability in views of both the nanocomposites synthesis and the nitrite determination performance.

Crude water extract of Psidium guajava Linn. leaves was applied in the microwave synthesis of zinc oxide nanoparticles. The particles were characterized by transmission electron microscopy, selected area electron diffraction, powder X-ray diffraction, UV–vis and IR spectroscopies, thermogravimetry, and particle size and surface area analyses. The yielded particles are of hexagonal phase with 60–180 nm size distribution. The essential and functions of biomolecules in the extract and the influences of different zinc salts on the synthesis are presented. Photocatalytic activities were revealed to be excellent toward the degradation of methylene blue, methyl orange and orange II. The influences of the dyes' molecular structures on the degradation are discussed.

The rapid and facile microwave method has been employed to synthesize [Tb2(TTHA)(H2O)4]·9H2O (I; H6TTHA = 1,3,5-triazine-2,4,6-triaminehexaacetic acid) microcrystals. Based on the photoluminescent emission of I, which can be selectively turned off upon the coordination of nitrite, the selective determination of nitrite in water was developed without the use of Griess reagents. With the use of smartphone camera as a detector, the quantitative analysis of nitrite was conducted within the CIELAB colorimetric space, revealing the relative standard deviation of less than 5% for the working range of 3–12 μg. Sensitivity, detection limit and quantification limit of the measurements were evaluated, providing the values of 0.732 (Lcontrol/Lsample)·μg−1, 1 μg and 3 μg, respectively.

A series of [LnIII1.375(pydc)2(H2O)4] (Ln = SmIII (I), EuIII (II), GdIII (III), TbIII (IV), DyIII (V), HoIII (VI), ErIII (VII) and pydc2− = 2,5-pyridinedicarboxylate) were synthesized and characterized, disclosing a non-porous and highly disordering three-dimensional frameworks. The framework architecture is described based on four unique LnIII centers of two different square antiprismatic coordination spheres and discussed with reference to the closely relevant lanthanide coordination frameworks of pydc2−. Influences of the subtle change in synthesis parameters on crystallographic disordering and therefore diversity of the framework architectures are presented. The temperature-dependent photoluminescent properties of the titled complexes were studied, revealing variation in sensitization efficiency of pydc2− and the bi-exponential behavior in time-dependent luminescent decay. The influences of the crystallographic disorder in the framework structures on photoluminescent properties are demonstrated. Based on the temperature-dependent photoluminescent properties of the bimetallic [EuIIIxTbIII1.375−x(pydc)2(H2O)4] (VIII-X) and [SmIIIxTbIII1.375−x(pydc)2(H2O)4] (XI-XIII), the life times and the energy transfer efficiencies of the common TbIII-to-EuIII and the rare TbIII-to-SmIII energy transfer process have been studied. Temperature sensing performance of VIII-X and the potential of XIII as white light emitting material are also included.

An unsaturated Mn(II)-centered metal-organic framework was synthesized. The presence of an unsaturated Mn(II) center, together with a guest-responsive structural changing feature, plays a crucial role for strong binding with water, leading to its potential application for water/ethanol separation. In addition, the present framework is thermally stable up to 400 °C, which is beneficial for the regeneration process after adsorption.

Based on the mixed phthalate (phth2-) and adipate (ad2-), [Nd2(ad)(phth)2(H2O)4] (I) and [Ln(ad)0.5(phth)(H2O)2] (Ln = EuIII (II), GdIII (III), TbIII (IV), DyIII (V), ErIII (VI), TmIII (VII), 1EuIII:10TbIII (VIII), 3EuIII:10TbIII (IX), and 5EuIII:10TbIII (X)) were synthesized and characterized. Complexes VIII-X show excellent ratiometric temperature sensing behavior in physiological and higher temperature ranges (303-423 K) rendered by the TbIII-to-EuIII energy transfer process. The efficiency of the process as illustrated through the lifetime measurements depends on both the EuIII:TbIII mole ratio and the temperature. The performance of X in terms of relative sensitivity ( Sr), temperature resolution, and measurement repeatability were determined, revealing the maximum Sr ( Sm) of 1.21%·K-1 at 303 K with reliable temperature resolution and excellent repeatability.

Four new microporous lanthanide coordination polymers of general formula [Ln(C8H3NO6)(L)0.5(H2O)]·3H2O (Ln = Pr, Nd, Sm and Gd, and L = C8H4O4 or C8H4O4/C8H3NO6) were hydrothermally synthesized using in situ ligand synthesis. The complexes are isostructural featuring the NbO type framework, which is constructed from chains of edge-sharing {LnO9} polyhedra. The one-dimensional channel extending in the [1 0 0] direction with an aperture of approximately 4 × 8 A2 houses water of crystallization, which are ordered in edge-shared pentagons by hydrogen bonding interactions. Evidence for the significance of the hydrogen bonding interactions in stabilizing the framework is presented. Crystallographic disorder in the organic ligands, including rare substitutional disorder, is described. The complexes show type I gas sorption isotherms characteristic of microporosity, and are thermally stable up to approximately 400 °C. The solid state luminescence properties of these complexes are included.

A 1D coordination framework, {[La2(o-phen)2(SO4)3(H2O)2]}n (1) (o-phen = 1,10-phenanthroline) was hydrothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR, and UV-Vis spectroscopy. The crystal of 1 crystallized in the triclinic P,1. space group, a = 10.3228(5) A, b = 12.3644(7) A, c = 12.6579(6) A, α = 72.323(2)°, β = 75.610(2)°, γ = 82.785(2)°, V = 1488.82(13) A3, Z = 2. The structure exhibits a neutral 1D framework representing a five-connected uninodal 1-periodic net of (3,6)(0,2) topology. The framework structure comprises TPRS-9 {LaO7N2} units, chelating o-phen ligands and bridging sulfates of 3.1110 and 4.2211 coordination modes. These 1D chains are extended into a 3D supramolecular structure by hydrogen bonding interactions of, R22 (n) patterns. Thermogravimetric analysis shows the structure to be thermally stable up to approximately 400°C. Photoluminescence investigations on Eu3+ and Tb3+ doped samples suggest the competition between the ligand-to-me...

The ionothermal synthesis of two intercalated two-dimensional zinc benzenedicarboxylates, EMIm2[Zn3(C6H4(COO)2)3Cl2] (I) and BMIm2[Zn3(C6H4(COO)2)3Cl2] (II), employing the ionic liquids 1-ethyl-3-methylimidazolium chloride (EMIm-Cl) and 1-butyl-3-methylimidazolium chloride (BMIm-Cl) as solvents, is reported. Detailed characterization by X-ray diffraction, elemental analyses, vibrational and optical spectroscopies, and thermogravimetric analysis is described. The two compounds display an anionic two-dimensional structure with the composition [Zn3(C6H4(COO)2)3Cl2]2− which is intercalated and charge neutralized by the imidazolium cations. The compounds are remarkably stable: neither begins to lose mass until they are heated above 300 °C, above which temperature ZnO is obtained. The structural transformation of the anionic layered compounds I and II to a neutral one-dimensional structure with the composition Zn(C6H4(COO)2)(H2O)2 is described. The derived neutral compound shows better thermal robustness. Both the parent and the transformed structures display blue luminescence, arising from ligand centered π → π∗ and n → π∗ transitions.

New series of [Ln2 (pydc)2(SO4) (H2O)x]·yH2O (H2pydc = 2,5-pyridinedicarboxylic acid), differing in number of the coordinating (x) and the crystallizing (y) water, have been hydrothermally synthesized and characterized: (i) x = 2, y = 6, and Ln = La, Pr and Nd; (ii) x = 3, y = 2 and Ln = Pr and Nd; and (iii) x = y = 0 and Ln = Pr and Nd. Influences of the subtle change in reaction temperature (80–180 °C) and time (1–7 days) on x and y values, and structural diversity of the titled complexes are reported. The association between x and y values and the hydrogen bonding interactions facilitated by the water molecules, the aromatic π-π interactions of the pydc2− ligand, as well as the coordination modes of both pydc2− and sulfate is discussed. Dissimilar thermogravimetric behaviors and the framework stabilities are presented.

Nanoparticles of cubic zinc ferrites ( F d 3 ¯ m , a = 8.41(3)–8.44(1) A) were synthesized as a single phase by an ultrasonic cavitation-assisted solvothermal technique using ethyl alcohol–water mixed solvents at temperatures of 150 °C or higher for 18 h or more. The influences of the ultrasonic cavitation and the use of C 2 H 5 OH–H 2 O mixed solvents in diminishing average particle size and in improving particle size uniformity were illustrated. The largest average size of nanoparticles obtained was 20 nm as measured from SEM photographs, with crystallite size of approximately 10 nm as estimated from XRD results. The room-temperature field-dependent magnetization of the nanoparticles obtained showed a characteristic S feature with magnetization of 24.32 emu/g at 1 T.

A new flexible triazine-based polycarboxylate metal–organic framework, [Sm2(TTHA)(H2O)4]·9H2O (I) (TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetate), has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction, elemental analysis and FT-IR spectroscopy. Crystal data for I are monoclinic C2/c, a = 12.6974(13) A, b = 16.7309(12) A, c = 14.8076(15) A, β = 91.452(8)°, V = 3,144.7(5) A3. Each SmIII ion is 9-coordinate in a distorted tri-capped trigonal prismatic geometry; but, the principal inorganic building block is {Sm2O16}, which comprises two of these polyhedra that share an edge. The complex exhibits a three-dimensional open-framework structure of approximately 31 % void volume, which comprises two types of channels oriented in three directions; [0 0 1], [1 1 0] and [−1 1 0]. The network can be simplified into either the cooperite (pts) or anatase (ant) topologies depending on the choice of nodes. The UV–Vis spectra of the compound are dominated by the absorption of the TTHA ligand. Thermogravimetric analysis shows that the loss of channel and coordinated water upon heating occurs in two distinct steps.

The isostructural coordination polymers, M(isonicotinate)(tyrosinate)(H2O)2 [M = Co or Ni] have been synthesized by microwave-assisted hydrothermal methods. These compounds crystallize in the non-centric space group P21. At 290 K, for the cobalt analogue the unit cell parameters are a = 6.0658(6), b = 15.540(2), c = 9.1328(9) A, β = 107.052(7)°, V = 823.05(16) A3; for the nickel compound a = 6.0946(8), b = 15.443(2), c = 9.1202(11) A, β = 107.803(10)°, V = 817.28(19) A3. The structure contains linear chains with composition [M(isonicotinate)]∞ in which the isonicotinate is arranged head-to-tail and binds to octahedral cations through both pyridine and monodentate carboxylate functions. At each metal centre the coordination is completed by two cis water molecules and tyrosinate that chelates to the metal centre through monodentate carboxylate and amine groups. The chains run parallel to the crystallographic [101] direction. Between the chains there is extensive hydrogen bonding between bound water and carboxylate groups. The cobalt compound loses water upon heating above room temperature and continues to lose mass in ill-defined steps upon further heating; in contrast the nickel compound loses mass in well-defined steps. An achiral one dimensional chain can be decorated with the chiral auxiliary tyrosine to produce a homochiral coordination polymer.

The microwave-assisted S N Ar reaction of 2,4,6-trichloro-1,3,5-triazine with various unprotected amino acids was developed for the synthesis of C 3 -symmetrical polycarboxylate ligands which can be used as structural directing units in metal–organic frameworks. The reactions were performed in water using a domestic microwave oven as the heating device. In comparison to the reactions performed under conventional heating, the reactions under microwave irradiation proceeded much more rapidly within 20 min to afford the desired ligands in comparative yields to those obtained by conventional heating.

Single crystal of a new polymorph of 1,3,5-triazine-2,4,6-triaminehexaacetic acid has been growth and characterized. The structure of the title polymorph crystallized in the monoclinic space group C2/c with the unit cell parameters a = 20.443(4) A, b = 10.5104(14) A, c = 9.8022(11) A, β = 118.212(6)°, V = 1855.9(5) A3, Z = 4, R = 0.112, Rw = 0.273 and S = 1.038. The principal feature of the new polymorph is characterized by a bundle of molecular columns each of which is built up of molecular units stacked along c in the offset face-to-face manner. Significance of hydrogen bonding interactions in regulating the assembly of molecules in the structure is then demonstrated. Detailed differences in molecular conformation, type and pattern of hydrogen bonding interactions are discussed and distinguished from the previous polymorph. The vibrational and electronic spectroscopic studies are included. Microwave-assisted crystal growth and structure of 1,3,5-triazine-2,4,6-triaminehexaacetic acid new polymorph.

The molecular structure of a second form of [Ni(2,2′-bipyridine)(H 2 O) 3 (NO 3 )](NO 3 ) is reported. The previous report is for a blue monoclinic polymorph. The second form is orthorhombic and crystallises as green blocks with unit cell parameters a = 9.1201(12) A, b = 14.444(2) A, c = 21.805(4) A, V = 2872.4(8) A 3 , Z = 8. The complex was characterised by elemental analysis, infrared spectroscopy, UV–Vis spectroscopy, and thermogravimetry. The bipyridine acts as a bidentate ligand to Ni 2+ and the octahedral coordination is completed by three water molecules and one monodentate nitrate ion. A second nitrate forms hydrogen bonds to the bound water molecules. The difference between the two forms in terms of the molecular geometry is described in relation to other similar compounds. The key difference between the two forms is the orientation of the two nitrate anions, and hence the hydrogen bonding present.

Layered lanthanide sulfate compounds with three different structures have been prepared and characterized. The compounds [C10H10N2][La(SO4)2]·2H2O (I), [C10H10N2][La(SO4)2(H2O)2]2 (IIa), [C10H10N2][Pr(SO4)2(H2O)2]2 (IIb), [C10H10N2][Nd2(SO4)4(H2O)2]2 (IIIa), [C10H10N2][Sm2(SO4)4(H2O)2]2 (IIIb), and [C10H10N2][Eu2(SO4)4(H2O)2]2 (IIIc) have anionic lanthanide sulfate layers separated by protonated bipyridine molecules. The layers are formed by the connectivity between the lanthanide polyhedra and sulfate tetrahedra. The formation of a two-dimensional La−O−La layer (Ia), Pr−O−Pr chains (IIb), and a tetramer cluster (IIIa) is noteworthy. The compounds exhibit honeycomb (I), square (IIa, IIb), and honeycomb (IIIa−IIIc) net arrangements, when the connectivity between the lanthanide ions is considered. Optical studies indicate the observation of characteristic metal-centered emission at room temperature. The Nd compound (IIIa) exhibits a two-photon upconversion behavior.

Two extended solids displaying both one-dimensional coordination polymer and two-dimensional hydrogen-bonded structural features has been prepared under microwave-assisted hydrothermal conditions. [Co(H2O)4(4,4′-bipyridine)](4,4′-bipyridineH2)·2(SO4)·2H2O (1) contains one-dimensional coordination polymer chains of composition [Co(4,4′-bipyridine)(H2O)42+]n that are linked into a three dimensional framework by hydrogen bonding through uncoordinated sulfate and water. Within this framework is located a twice protonated 4,4′-bipyridine molecule (C10N2H102+) which forms two short N–H ⋯ O hydrogen bonds and eight further non-classical C–H ⋯ O interactions. The close approach of guest and framework and the large number of interactions between them suggest the cation is important in templating this phase. [Co2(4,4′-bipyridine)2(SO4)2(H2O)6]·4(H2O) (2) displays one dimensional chains of cobalt-bipyridine which are sinusoidal in nature. Two sets of these chains run parallel to the crystallographic [2 1 2] and [ 2 ¯ 1 2 ¯ ] directions. Two-dimensional hydrogen-bonded sheets parallel to the xz plane link these; further hydrogen bonds to uncoordinated water help to form a three-dimensional honeycomb network with the centroids of the six-membered rings aligned parallel to the a-axis. The use of microwave synthesis for framework solids of this type is described and the structures of the frameworks and the interactions responsible for their assembly are discussed. The thermal and spectroscopic behaviour of the two phases are described.

Microwave synthesis was used to grow single crystals of a new organic–inorganic supramolecular assembly, [V10O27(OH)] · 2(C6N2H14) · (C6N2H13) · (C6N2H12) · 2H2O, in a very short time compared to the conventional solution technique. In order to generate crystals suitable for single crystal experiments, an equimolar mixture of reactants and a few hours of microwave heating are required. Although non-merohedral twinning is an inherent problem, the crystal structure can be solved and refined in the orthorhombic space group Pna21 with a = 20.972(4) A, b = 10.3380(14) A, c = 20.432(3) A, Z = 4, with an excellent result, R(F2) = 0.0431. The assembly is hydrogen bond-assisted and built up of the monoprotonated decavanadate and 1,4-diazabicyclo[2.2.2]octane of various degrees of protonation. The number and location of protons on both the inorganic and organic motifs govern the formation of the extensive hydrogen bonding network, which in turn regulates the assembly architecture.

The first example of polyoxovanadate layered framework with a cobalt coordination complex as a pillaring unit, CoII(μ-C2N2H8)2[V 4 IV V 2 V O14], was readily synthesized under hydrothermal conditions. The structure can be solved and refined in monoclinic P2 1 /n with a = 9.143(3) A, b = 6.5034(11) A, c = 15.874(4) A, β = 101.90(2), V = 923.6(4) A3 and Z = 2. The crystal structure comprises two-dimensional {V 4 IV V 2 V O14}2− layers extending parallel to [101], constructed from tetrahedral {VVO4} and square pyramidal {VIVO5} building units. Adjacent layers are linked through the octahedral {CoIIO2(μ-C2N2H8)2} pillars, within which the CoII resides on an inversion center. The structure displays N–H···O and C–H···O hydrogen bonding between the ethylenediamine and vanadium oxide layers. A new polyoxovanadate layered framework pillared with a cobalt coordination complex, CoII(μ-C2N2H8)2[V 4 IV V 2 V O14], has been prepared hydrothermally and fully characterized.

The so-called sonocatalyzed ammonothermal technique has been developed for the preparation of lithium niobate fine powders from commercially as-received niobium pentoxide and lithium nitrate. The present work shows that the application of ultrasonic activation prior to the ammonothermal treatment can produce a single phase lithium niobate fine powder at a relatively low temperature of 220°C. The influences of Li-precursors, ammonia solution concentration, reaction temperature and time, as well as Li:Nb mole ratio - which is evidentially the most critical factor promoting a single phase formation - are discussed.

A pillared-layered coordination polymer of formula Co(H2NCH2CH2NH2)SO4 (1) has been synthesized under solvothermal condition, and fully characterized. The three-dimensional structure of 1 is built up from cobalt sulfate sheets, each of which is composed of regularly alternating CoO4N2 octahedra and SO4 tetrahedra, with ethylenediamine pillars connecting the adjacent sheets. The coordinate covalent and hydrogen bonds have been revealed to exhibit an important role in the organization of the structure. The compound is found to be thermally stable up to, and above, 573 K and exhibits paramagnetic behavior at room temperature.

A series of four diaminoalkane templated vanadium oxide polymeric frameworks, [V 2 IV O8V 2 V O2](C2H10N2), [V 2 IV O8V 2 V O2](C3H12N2), [V 4 IV O10V 2 V O4](C4H14N2) and [V 4 IV O10V 2 V O4](C5H16N2), have been successfully prepared under hydrothermal conditions. The crystal structures are fully characterized revealing layered structures composed of common inorganic building units, namely {VIVO5} square pyramids and {VVO4} tetrahedra. The layer registries are different depending on the molecular structure of the diaminoalkanes, and can be accounted for by the organic-inorganic interface interactions. The analysis of hydrogen bonds indicates their important role in directing two- and three-dimensional structural architectures. The influences of different diaminoalkanes are also apparent in both thermogravimetric and complex magnetic behaviors, and are discussed in details.

Effect of calcination conditions on phase formation and particle size of lead zirconate (PbZrO3) powders synthesized by a solid-state reaction with different vibro-milling times was investigated. A combination of the milling time and calcination conditions was found to have a pronounced effect on both the phase formation and particle size of the calcined PbZrO3 powders. The calcination temperature for the formation of single-phase perovskite lead zirconate was lower when longer milling times were applied. The optimal combination of the milling time and calcination condition for the production of the smallest nanosized (∼28 nm) high purity PbZrO3 powders is 35 h and 750 °C for 4 h with heating/cooling rates of 30 °C/min, respectively.

Hydrothermal synthetic parameters were studied and optimized for the preparation of new coordination polymeric materials based on Co(II) and 4,4′-bipy. A new polymeric compound, [Co2(H2O)2(OH)2(4,4′-bipy)8](NO3)2·2(4,4′-bipy) 10(H2O) (1), was prepared and structurally characterized by single crystal experiment. The framework of (1) is made up of two different one-dimensional substructures, i.e., the neutral chain A and positively charged chain B, both of which share the same nodes and node linkers. This is rarely found, especially from a one-pot crystal growth technique. Two other crystals were also identified, i.e., [Co(SO4)(H2O)3(4,4′-bipy)]·2(H2O), and K2Co(H2O)6(SO4)2. The optimization of synthetic parameters apparently favors the formation of different polymeric structures, and this can be experimentally fine tuned. The influences of these parameters on phase formation, purity and crystal growth are discussed. The complicated thermogravimetric property of the new compound is also reported.