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A new gadolinium(III)–pyridine‐2,5‐dicarboxylic acid (GdIII–2,5‐H2pdc)‐based three‐dimensional coordination polymer, namely, poly[dimethylazanium [bis(μ‐pyridine‐2,5‐dicarboxylato)gadolinium(III)]], {[(CH3)2NH2][Gd(C7H3NO4)2]}n, CP‐1, has been synthesized via a typical solvothermal method. The as‐synthesized material was characterized in the solid state using single‐crystal X‐ray diffraction, powder X‐ray diffraction, thermogravimetric analysis and FT–IR spectroscopy. During the synthesis of CP‐1, the in situ dimethylformamide (DMF) promotes the formation of a dimeric unit and these act as secondary building blocks in the assembly of a three‐dimensional anionic {[Gd(pdc)2]−}∞ framework. The framework has channels along the c axis which are filled by dimethylazanium cations. Interestingly, the framework shows a helical‐type assembly running down the a axis. A Hirshfeld surface analysis of CP‐1 suggests that extra stability is provided by hydrogen‐bonding interactions. The magnetic properties of CP‐1 showed weak antiferromagnetic couplings between adjacent Gd3+ ions. [ABSTRACT FROM AUTHOR]

Five transition metal–BTC–BIm based coordination polymers, namely [Zn2(HBTC)2(BIm)2(H2O)2]·(H2O)3, 1; [2-HABI]2[Zn2(BTC)2(2-ABI)(H2O)]·(H2O)5, 2; [Cu3(BTC)2(BIm)6][solvent], 3; [Co4(BTC)3(BIm)6][solvent], 4; and [(CH3CH2)2NH2][Zn(BTC)(BIm)]·(H2O), 5 have been synthesized and characterized using complementary techniques like single crystal X-ray analysis, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA) (BTC = 1,3,5-benzene tricarboxylic acid, BIm = benzimidazole and 2-ABI = 2-aminobenzimidazole). Crystal structure analysis of these compounds showed that 1 forms a 1D chain, 2 and 3 have 2D layers while 4 and 5 have three-dimensional architectures. 3 forms a hexagonal bronze sheet, 4 has a three-dimensional network with embedded paddlewheel SBUs and helical assembly, and 5 crystallizes in a polar space group (Pna21) with 3D helical networks with adamantane-type topology. The dielectric properties of 5 showed that the dielectric constant rapidly decreases with an increase in frequency suggesting dipole relaxation at low frequencies. [ABSTRACT FROM AUTHOR]

We report single crystal X-ray investigations of three d10 metal based oxalate–sulfite inorganic–organic hybrid open framework materials, namely [Zn2(SO3)2(C2O4)0.5(C6N2H13)]·(H2O)2, 1, [C4N2H12]0.5[Zn2(SO3)2(C2O4)0.5(H2O)2], 2 and [C4N2H12][Cd2(SO3)2(C2O4)(H2O)]·H2O, 3 which show layered and three dimensional structures with different organic templates. These materials were synthesized under hydrothermal conditions and characterized by techniques such as single crystal X-ray diffraction, dipole moment calculations, FTIR, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The common feature for 1 and 2 is the interconnection of embedded zinc-sulfite chains via oxalate anions in the framework and in 3, cadmium-oxalate chains are interconnected via sulfite anions. The coordination geometries of metal(ii) ions vary significantly resulting in a ladder-like layered structure in the case of 1, a 3D framework in case of 2 and a layered structure with an embedded one-dimensional channel in 3. The observed structures can also be partly attributed to the influence exerted by the presence of different structure directing agents (SDA) in the lattice. The dipole moments for metal polyhedra 1, 2 and 3 were calculated from bond valence analyses and are 2.39 D for Zn(1)O4N polyhedra and 1.66 D for Zn(2)O4 polyhedra in 1, 24.90 D for Zn(1)O6 and 29.52 D for Zn(2)O4 in 2 and 5.82 D for Cd(1)O7 and 2.90 D for Cd(2)O6 in 3. [ABSTRACT FROM AUTHOR]

The crystallographic signatures and characterization of two novel mixed metal hybrid open-frameworks [Na2Mn2(C2O4)(SO3)2(H2O)2] 1 and [NaEu(C2O4)(SO3)(H2O)3] 2 are reported for the first time; they are synthesized under hydrothermal conditions to generate 3D assemblies and honeycomb-like structures. They were further characterized by complementary techniques like PXRD, TGA and DSC. The magnetic properties of 1 show antiferromagnetic interactions between the metal centers and compound 2 shows good photoluminescence properties. [ABSTRACT FROM AUTHOR]

Protonation of trans-1,2-bis(4-pyridyl)ethylene (4,4′-bpe) with dilute sulfuric acid (33 %) afforded a protonated adduct [{4,4′-bpe⋅2 H+}2{HSO4}−2{SO4}−2{H2O}2] ( 1). The neighboring olefinic bond in 1 is in a suitable range (3.931-4.064 Å) to undergo a photochemical [2+2] cycloaddition reaction. Upon irradiation with UV light (365 nm), 1 undergoes a molecular sliding involving the 4,4′-bpe⋅2 H+ units, affording 2, stabilized through OSO4⋅⋅⋅π interactions. Heating 1 to 50° C leads to a 3D hydrogen-bonded organic framework (HOF) ( 3). This process occurs through thermal dissociation of the bisulfate anion. Diffusion of iodine through the crystal lattice of 1 and 3 enables the reduction of sulfate to bisulfate, affording a 1D hydrogen-bonded chain ( 4). Solid-state 13C CPMAS NMR, IR, DSC, and powder XRD studies further support stimuli-responsive structural tuning through crystal-to-crystal transformation. All these conversions occur with significant translational and rotational movements along with a series of bond-breaking and bond-forming processes. [ABSTRACT FROM AUTHOR]

The crystallographic signatures and characterization data of two novel organically templated open-framework zinc-sulfites (NH3CH2CH2NH3)[Zn3(SO3)4], 1, and (CN3H6)2[Zn(SO3)2], 2, are reported for the first time, synthesized under hydrothermal conditions using different amines, namely, ethylenediamine and guanidine, to generate 2D (for 1) and 3D (for 2) assemblies with 4-, 6-, 8- and 12-membered rings. [ABSTRACT FROM AUTHOR]

A series of six lanthanide‐containing germanotungstates of the formula: [(Ln2GeW10O38)4(W3O8)(OH)4(H2O)2]26− (Ln=Sm (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6) have been synthesized under ambient conditions. The synthetic procedure involves the use of trilacunary Na10[A‐α‐GeW9O34]⋅16H2O as a preformed precursor along with lanthanide salts in 0.5 M potassium chloride solution. The interaction of the trilacunary Na10[A‐α‐GeW9O34]⋅16H2O with the lanthanide salts leads to the formation of a tetrameric structure with four [GeW10O36]8− dilacunary Keggin units incorporating eight lanthanide ions and three additional tungsten atoms. All the polyanions were structurally characterized by Fourier‐transform infrared spectroscopy (FT‐IR), Single Crystal X‐ray Diffraction (SC‐XRD), UV/Visible spectroscopy, thermogravimetric analysis (TGA), electrochemistry, Electron‐spray ionization mass spectroscopy (ESI‐MS), Powder X‐ray diffraction (PXRD) and photoluminescence. FT‐IR spectroscopy reveals that all the polyanions are isomorphous and SC‐XRD shows that all the polyanions are isostructural and crystalize in the triclinic crystal system with P1‾ space group. Some of the polyanions show good photoluminescence properties. The cyclic voltammograms (CVs) of all the six compounds exhibit the same shape, each being composed of a pronounced reduction wave. [ABSTRACT FROM AUTHOR]

We report X-ray crystallographic investigations of two novel metal–organic frameworks (MOFs) by using 4,4′,4′'-s-triazine-2,4,6-triyltribenzoic acid [H 3 TATB] ligand with Ca metal for 1 and 1,3,5 benzene tri-carboxylic acid [H 3 BTC] ligand with Co metal for 2 respectively. The compound [Ca 6 (TATB) 4 (H 2 O)(DMA) 4 ] ( 1 ); (where DMA = dimethylacetamide); was successfully synthesized in a sealed tube at 110 °C for 72 h and shows the formation of a 3D network with embedded 1D channels which are occupied by solvent molecules. The structure of the compound 1 is relatively new and its structural differences with the reported Cu-TATB compounds are noteworthy. The compound Co-HKUST ( 2 ) was synthesized by solvothermal method at 140 °C for 72 h. Paddlewheel secondary building units are used to construct Co-HKUST ( 2 ) which is isostructural analogue of HKUST-1 enriching the series which consists of Cr, Fe, Ni, Zn, Mo, and Ru analogues. Both 1 and 2 are metastable MOFs characterized by complementary techniques namely powder X-ray diffraction and FTIR analysis. [ABSTRACT FROM AUTHOR]

An unprecedented thermal response is observed in [(4,4′-bpe·2H+)(HSO4−)2] (1), a hydrogen-bonded 1D coordination polymer. While 1 was photostable to irradiation at 365 nm, upon heating at 70 °C for 1 h, it transformed into 1·ph, a 2D polymer, through single-crystal-to-single-crystal transformation (SCSCT). In this conversion, a series of bonds are broken and re-formed simultaneously, leading to major changes in the packing pattern which is quite rare in SCSCT. [ABSTRACT FROM AUTHOR]

A series of copper (II) (1 and 3) and cobalt (II/III) (2, 4 and 5) complexes comprising different imino‐phenolate ligands DCH, DTH and DBH2 (where DCH = 2,4‐dichloro‐6‐((mesitylimino)methyl)phenol, DTH = 2,4‐di‐tert‐butyl‐6‐((mesitylimino)methyl) phenol and DBH2 = 2,4‐dibromo‐6‐((mesitylimino)methyl)phenol) have been prepared with excellent yield and high purity. By utilizing different spectroscopic tools such as UV–visible, electrospray ionization (ESI)‐mass, Fourier‐transform infrared (FTIR) spectrometry and elemental analysis, the prepared complexes (1–5) were thoroughly characterized. The molecular structure of the synthesized complexes was ascertained by using single‐crystal X‐ray diffraction studies (SCXRDs). The experiment reveals that Complexes 1–5 bind to calf thymus DNA (CT‐DNA) through non‐intercalative way with good interacting abilities. However, 1–5 are excellent quenchers of the fluorescence intensity of bovine serum albumin (BSA) following the static pathway. Additionally, they had shown remarkable cytotoxic potential against MCF‐7 (mammary gland adenocarcinoma) and A549 (lung adenocarcinoma) cell lines. The IC50 values associated with these complexes were much lower than the conventional drug cisplatin. Apoptosis‐induced cell death was confirmed from the DNA fragmentation studies and Hoechst 33342 staining. The 2′,7′‐dichlorofluorescein diacetate (DCFDA) assay indicates that the complex mediated reactive oxygen species (ROS) generation is accountable for governing the apoptosis mechanism via oxidative cell distress. Apart from these studies, by carrying out density functional theory (DFT) method, highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO) energy gap calculations and optimized structures of the synthesized complexes were accomplished. [ABSTRACT FROM AUTHOR]

A unique hexanuclear zinc(II) (1) and two mononuclear copper(II) (2 and 3) complexes anchored with imino phenol ligand HL1 and HL2 were synthesized with good yield and purity (where HL1 = 4‐tert‐butyl‐2,6‐bis((mesitylimino)methylphenol and HL2 = 5‐tert‐butyl‐2‐hydroxy‐3‐((mesitylimino)methyl)benzaldehyde). These complexes were characterized by utilizing various spectroscopic protocols like NMR, FTIR, UV as well as ESI‐Mass spectrometry, elemental analysis and single crystal X‐ray diffraction studies. Their potential to bind calf thymus DNA (CT‐DNA) was tested utilizing different techniques such as UV–visible and fluorescence spectroscopy. The experiment implies that they interact with CT‐DNA via non‐intercalative mode with moderate capabilities (Kb ~ 104 M−1). On the other hand, these complexes have high capabilities to quench the fluorescence of bovine serum albumin (BSA) following the static pathway. In addition, they are active catalysts for the oxidation reaction of 3,5‐di‐tert‐butylcatechol (3,5‐DTBC) to 3,5‐di‐tert‐butylquinone (3,5‐DTBQ) under aerobic condition. From the recorded EPR signals of all complexes, it has been concluded that the oxidation reaction proceeds via ligand oriented radical pathway instead of metal based redox participation. Kinetic studies using 1–3 indicate that it follows Michaelis–Menten type of equation with moderate to high turnover number (kcat). Apart from these aspects, complexes 1–3 were screened for their cytotoxic behavior towards HeLa cells (human cervical carcinoma) and found quite active with comparable IC50 values to cisplatin. [ABSTRACT FROM AUTHOR]