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A doubly interpenetrated Cu(II)‐organic framework with formula [{Cu2(L)2(4,4′‐bpdc)2(H2O)2} ⋅ 8H2O ⋅ CH3OH]α (1) (where, L=N2, N6‐di(pyridin‐4‐yl)naphthalene‐2,6‐dicarboxamide and 4,4′‐bpdc=[1,1′‐biphenyl]‐4,4′‐dicarboxylate ion) has been synthesized and characterized with the help of several spectroscopic and analytical techniques including single crystal X‐ray analysis. A single crystal X‐ray analysis reveals that 1 exhibit interpenetrated two‐dimensional sheet‐like structure containing elongated channels of cross‐section 11.09×31.22 Å2 along the a‐axis. Finally, 1 has been exploited as a heterogeneous catalyst for the ipso‐hydroxylation of arylboronic acids yielding up to 99 % of the respective phenolic product. Importantly, the catalyst can be reused for five successive cycles without having a significant loss in its catalytic efficiency. [ABSTRACT FROM AUTHOR]

We report the synthesis and structural characterization of two coordination polymers (CPs), namely; [{Zn(L)(DMF)4} ⋅ 2BF4]α (1) and [{Cd(L)2(Cl)2} ⋅ 2H2O]α (2) (where L=N2,N6‐di(pyridin‐4‐yl)naphthalene‐2,6‐dicarboxamide). Crystal packing of 1 reveals the existence of channels running along the b‐ and c‐axis filled by the ligated DMF and lattice anions, respectively. Whereas, crystal packing of 2 reveals that the metallacycles of each 1D chain are intercalating into the groove of adjacent metallacycles resulting in the stacking of 1D loop‐chains to form a sheet‐like architecture. In addition, both 1 and 2 were exploited as multifunctional materials for the detection of nitroaromatic compounds (NACs) as well as a catalyst in the ipso‐hydroxylation of aryl/heteroarylboronic acids. Remarkably, 1 and 2 showed high fluorescence stability in an aqueous medium and displayed a maximum 88% and 97% quenching efficiency for 4‐NPH, respectively among all the investigated NACs. The mechanistic investigation of NACs recognition suggested that the fluorescence quenching occurred via electron as well as energy transfer process. Furthermore, the ipso‐hydroxylation of aryl/heteroarylboronic acids in presence of 1 and 2 gave up to 99% desired product yield within 15 min in our established protocol. In both cases, 1 and 2 are recyclable upto five cycles without any significant loss in their efficiency. [ABSTRACT FROM AUTHOR]

In the present work, a variety of symmetrical and unsymmetrical 2-pyridyl aryl selenium (IV) chlorides or bromides were prepared by the dropwise addition of a dilute solution of bromine or sulfuryl chloride to the corresponding 2-pyridyl aryl selenide in dried organic solvent with continuous stirring at 0 °C. Removal of the solvent under reduced pressure resulted in the synthesis of, 2-pyridyl aryl selenium (IV) bromides or chlorides, respectively, in quantitative yields. The titled dihalides prepared were characterized by elemental analysis, spectroscopic studies, and single crystal X-ray analysis. Single crystal X-ray analysis revealed that the 2-pyridyl aryl selenium (IV) bromides/chlorides have a distorted trigonal bipyramidal structure. The pyridyl and phenyl rings along with a lone pair of electrons on selenium are at equatorial positions whereas chloride/bromide atoms at axial positions of the distorted trigonal bipyramidal structure. [ABSTRACT FROM AUTHOR]

Herein, we report the syntheses and characterization of two novel CdII-based metal–organic frameworks (MOFs) with the formulae: [{Cd(INH)(hpdia)}·3H2O]α (Cd-MOF-1) and [{Cd(INH)(bdc)}·DMF]α (Cd-MOF-2) (INH = isoniazid, hpdia = 5-(4-hydroxyphenylazo)isophthalic acid, and H2bdc = 1,4-benzenedicarboxylic acid) using the mixed ligand and solvothermal protocol. Single crystal X-ray analysis reveals that Cd-MOF-1 and Cd-MOF-2 display overall 2D porous framework architectures. Cd-MOF-1 and Cd-MOF-2 have a two-dimensional zigzag network composed of a 4-connected uninodal network with sql topology and point symbol {4·4·6·2}. TGA analysis suggests that Cd-MOF-1 and Cd-MOF-2 are thermally stable. These MOFs exhibit fascinating luminescence properties. Cd-MOF-2 shows intense blue emission whereas Cd-MOF-1 shows nearly visibly intense white light emission with a CIE index of (0.34, 0.32) having a color correlated temperature (CCT) of 5121 K. Herein, we show how one can tune their spectral output by varying the emissive and non-emissive organic linkers. [ABSTRACT FROM AUTHOR]

We report the syntheses and structural characterization of a Zn(II) metallacycle [Zn2{(L)2(DMF)2(NO3)2}]·(NO3)2 (1) along with a Cd(II) coordination polymer [{Cd1(L)2(DMF)2}·(NO3)2]n (2) (where L = N,N′-bis-(3-pyridyl)terephthalamide; DMF = dimethylformamide) and their utilization as fluorescent probes for highly selective recognition (turn-off) of Fe3+ and CrO42− ions. Compounds 1 and 2 were prepared by utilizing ligand L and the nitrate salt of zinc and cadmium, respectively. Single crystal X-ray analysis reveals that 1 adopts an overall Zn(II) metallacycle architecture, whereas 2 displays a one-dimensional (1D) polymeric structure. Both 1 and 2 showed high fluorescence stability in aqueous solution and selectively detected Fe3+ and CrO42− ions with high quenching constants and low detection limits of 2.34 × 106 M−1 and 0.153 μM for Fe3+, 6.72 × 105 and 0.205 μM for CrO42− (for 1); 3.25 × 106 and 0.193 μM for Fe3+, 6.94 × 105 and 0.155 μM for CrO42− (for 2). Notably, ligand L itself did not display any type of recognition for any ions in DMF as well as in aqueous media. Moreover, 1 and 2 were also employed as heterogeneous catalysts for the ring-opening reaction (ROR) of epoxides with various assorted amines and up to 95% yield (TON, 47.5 and TOF, 11.9 h−1) was observed with perfect regioselectivity in the case of styrene oxide. [ABSTRACT FROM AUTHOR]

Bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)telluride (2) has been synthesised in good yield by reacting 1-(2-chloroethyl)-3,5-dimethylpyrazole with in situ prepared sodium telluride, Na2Te in an aqueous solution. A number of new organotellurium halides from bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)telluride have been synthesised by using different halogenating reagents. Reaction of 2 with bromine gave bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)telluride dibromide (5a) in addition to unexpected product bis(2-(4-bromo-3,5-dimethyl-1H-pyrazol-1-yl)ethyl)telluride dibromide (5b). All compounds were characterized by different spectroscopic techniques viz., 1H, 13C, 125Te NMR, Mass spectroscopy, IR and CHN analysis. EDXRF studies have also been employed to confirm the identity of 5a and 5b. Thermal gravimetric analysis of bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)telluride (IV) chloride (4) and bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)telluride (IV) iodide (5c) reveals the thermal stability of these molecules above 100°C. The X-ray studies of 5c shows trigonal bipyramidal geometry around tellurium atom and intermolecular secondary interaction viz., C-H π stacking between H23A and C22 showing a supramolecular packing between two molecules. [ABSTRACT FROM AUTHOR]

A new series of selenoester derivatives of imidazo[1,2-a]pyridine and imidazo[1,2-a]pyrimidine was synthesized under mild conditions using a simple methodology by the reaction of in situ generated sodium selenocarboxylates with 2-(chloromethyl)imidazo[1,2-a]pyridine/pyrimidine (3a–b) in water and ethanol. Excellent yields of phenyl/4-tolyl selenoesters of imidazo[1,2-a]pyridine/pyrimidine (6a–b and 6e–f) were obtained in water, whereas 4-methoxyphenyl/4-chlorophenyl/2-thienyl selenoesters of imidazo[1,2-a]pyridine/pyrimidine (6c–d and 6g–i) could only be synthesized in ethanol. Further, a series of reactions was carried out with 6e as a model compound in order to study the reaction behavior of selenoesters with mercury(ii) chloride (HgCl2). The deprotection of compound 6e by HgCl2 was carried out in the presence of K2CO3 under different conditions to obtain bis(imidazo[1,2-a]pyrimidin-2-ylmethyl)selenide (8) and bis(imidazo[1,2-a]pyrimidin-2-ylmethyl) diselenide (9) along with a small amount of less soluble bis((imidazo[1,2-a]pyrimidin-2-ylmethyl)selanyl)mercury (10). The mercury–selenium complex 10 has a short shelf life and decomposes to give HgSe, which was characterized using EDX analysis. The structure of compound 9 was established with X-ray crystallography. The formation of HgSe indicates that the selenoester derivatives may prove useful in the treatment of HgCl2 induced toxicity. [ABSTRACT FROM AUTHOR]

Recent advancement in nanoscience and nanotechnology has witnessed numerous triumphs of zinc oxide (ZnO) nanomaterials due to their various exotic and multifunctional properties and wide applications. As a remarkable and functional material, ZnO has attracted extensive scientific and technological attention, as it combines different properties such as high specific surface area, biocompatibility, electrochemical activities, chemical and photochemical stability, high-electron communicating features, non-toxicity, ease of syntheses, and so on. Because of its various interesting properties, ZnO nanomaterials have been used for various applications ranging from electronics to optoelectronics, sensing to biomedical and environmental applications. Further, due to the high electrochemical activities and electron communication features, ZnO nanomaterials are considered as excellent candidates for electrochemical sensors. The present review meticulously introduces the current advancements of ZnO nanomaterial-based chemical sensors. Various operational factors such as the effect of size, morphologies, compositions and their respective working mechanisms along with the selectivity, sensitivity, detection limit, stability, etc., are discussed in this article. [ABSTRACT FROM AUTHOR]