73 research outputs found

    Synthesis of Organo-metallic Coordination Polymers for Thermoelectric Application

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    As an intriguing class of thermoelectric (TE) candidates, organometallic coordination polymers (OMCPs) have become a new research focus in this area, regardless of the extensive research on inorganic and organic thermoelectric materials. This thesis showcases the synthesis and comprehensive characterization of a series of linear OMCPs based on metal-bis(dithiolato) coordination, Ni-ett, Ni-diett and Ni-btt (Chapter 2). The studies proved that changing organic ligands is a successful strategy to tune the thermoelectric properties of OMCPs, including electrical conductivity, Seebeck coefficient and power factor. By developing complex model for analogous spectroscopic study, we proved the polymer frames of three OMCPs are radial involving. Moreover, alternative synthetic route was also developed for polymer Ni-btt. Meanwhile, a couple of structural isomeric ligands OMCPs (Chapter 3), benzene-1,2,3,4-tetrakis(thiolate) and benzene-1,2,4,5-tetrakis(thiolate), were employed to synthesize mono-ligand OMCPs (Ni-ibtt and Ni-btt) and dual-ligand OMCPs Ni(ibtt)x(btt)1-x. The comparative study upon their thermoelectric properties was correlated with their structural difference in both intrachain and interchain characters. Regardless of organic bridging ligand, the metal center is the other most important role on the thermoelectric properties of OMCPs. Systematic comparison among OMCPs with different metal centers cross reports is usually unfeasible, as chemical composition and properties for a certain OMCP formula usually (like Ni-ett) differ from ii report to report and involve multiple reaction and measurement factors. In this study, OMCPs with various metal cations were synthesized in the M-ett and M-btt system to conduct a parallel comparison in their thermoelectric performance (Chapter 4). Preliminary molecular design and synthesis work were also carried out to experimentally obtain the OMCPs based on benzenetetrathiolate backbone with different sidechains, to examine the effect of sidechains on thermoelectric properties in this system

    Bis[4-oxido-2-oxo-2,3-di­hydro­pyrimidin-1-ium-5-carboxyl­ato(1.5−)-κ2 O 4,O 5]bis­(1,10-phenanthroline-κ2 N,N′)dysprosium(III) dihydrate

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    In the title compound, [Dy(C5H2.5N2O4)2(C12H8N2)2]·2H2O, the DyIII ion is located on a twofold rotation axis and is coordinated in a square-anti­prismatic geometry by two chelating 1,10-phenanthroline mol­ecules as well as two 4-oxido-2-oxo-2,3-di­hydro­pyrimidin-1-ium-5-carboxyl­ato(1.5−) anions. N—H⋯O and O—H⋯O hydrogen bonds help to stabilize the crystal structure. The H atom involved in an N—H⋯N hydrogen bond is disordered around a twofold rotation axis

    N-(1H-1,2,4-Triazol-5-yl)pyridine-2-carboxamide

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    In the structure of the title compound, C8H7N5O, the pyridine ring and the imidazole ring are nearly coplanar, making a dihedral angle of 2.97 (15)°. An intra­molecular N—H⋯O hydrogen bond occurs. In the crystal mol­ecules are connected by inter­molecular hydrogen bonds and π–π stacking inter­actions between neighboring imidazole rings [centroid–centroid distance = 3.5842 (5) Å and off-set angle = 21.77°], leading to the formation of a two-dimensional supra­molecular sheet

    4,4′-Bipyridinium 1,4-phenyl­ene­diacetate

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    The title compound, C10H10N2 2+·C10H8O4 2−, has inversion centres located at the geometric centres of the 1,4-phenyl­enediacetate anion and 4,4′-bipyridinium cation. The anions and cations are connected by N—H⋯O hydrogen bonds, forming one-dimensional supra­molecular chains, which inter­act with each other via π–π inter­actions [centroid–centroid distance = 3.938 (2) Å], building a two-dimensional supra­molecular sheet

    Luminescent and Swellable Conjugated Microporous Polymers for Detecting Nitroaromatic Explosives and Removing Harmful Organic Vapors

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    Four new conjugated microporous polymers (CMPs) were synthesized by a Buchwald–Hartwig (BH) cross-coupling reaction of tri- and tetrafunctionalized precursors to yield materials with tunable surface area and pore size distribution. This approach yielded LPCMP1–4, CMPs with significantly higher Brunauer–Emmett–Teller (BET) surface areas (more than 5 times higher) than other related BH-based CMPs. These CMPs possess not only high BET specific surface areas and high chemical and thermal stabilities, but also exhibit outstanding swellability. To the best of our knowledge, swellable behavior was studied in great detail for CMPs for the first time, with the greatest degree of swelling for methanol reaching 16.5 and 16.3 mL g–1 for LPCMP1 and LPCMP3, respectively. Owing to their excellent swellability, we further studied the adsorption capacity of these CMPs for different toxic organic vapors (including toluene and methanol). LPCMP1 and LPCMP3 adsorbed 124 and 117 mg g–1 toluene, respectively, at saturated vapor pressure. For methanol, the adsorption capacities of LPCMP1 and LPCMP3 were up to 250 and 215 mg g–1, respectively, which are the highest recorded values when compared with published data for CMPs, HCPs, MOFs, and porous carbons. These materials are promising candidates for the removal and elimination of hazardous organic vapors and chemical warfare agents. Moreover, all the polymers show high sensitivity to nitroaromatic explosives. LPCMP2 and LPCMP4 exhibit high selectivity for TNT and may be suitable as new candidates to selectively detect TNT for security or environmental applications

    Are Proselfs More Deceptive and Hypocritical? Social Image Concerns in Appearing Fair

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    Deception varies across individuals and social contexts. The present research explored how individual difference measured by social value orientations, and situations, affect deception in moral hypocrisy. In two experiments, participants made allocations between themselves and recipients with an opportunity to deceive recipients where recipients cannot reject their allocations. Experiment 1 demonstrated that proselfs were more deceptive and hypocritical than prosocials by lying to be apparently fair, especially when deception was unrevealed. Experiment 2 showed that proselfs were more concerned about social image in deception in moral hypocrisy than prosocials were. They decreased apparent fairness when deception was revealed and evaluated by a third-party reviewer and increased it when deception was evaluated but unrevealed. These results show that prosocials and proselfs differed in pursuing deception and moral hypocrisy social goals and provide implications for decreasing deception and moral hypocrisy

    Association between angiotensin-converting enzyme inhibitor-induced cough and the risk of lung cancer: a Mendelian randomization study

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    Background: Observational studies and meta-analyses have demonstrated a positive correlation between the use of angiotensin-converting enzyme inhibitors (ACEIs) and lung cancer. However, the findings remain controversial; furthermore, the relationship between ACEI-induced cough and lung cancer development remains unknown. We used Mendelian randomization (MR) to verify the association between ACEI use, ACEI-induced cough, and the risk of lung cancer.Methods: We performed a two-sample MR analysis to determine the unconfounded relationships between ACE inhibition, which mimics the effects of ACEIs, and genetic proxies for ACEI-induced cough and lung cancer. Single nucleotide polymorphisms that imitate ACE receptors and ACEI-induced cough were collected and integrated into a meta-analysis of existing genome-wide association studies for various lung cancers. The relationship was quantified using inverse variance weighting, weighted median, and MR-Egger methods.Results: A statistically significant association was observed between ACE inhibition and the risk of small cell lung cancer for Europeans (excluding rs118121655/rs80311894). Associations were identified between ACEI-induced cough and the risk of lung cancer for Europeans, although not for Asians, and between ACEI-induced cough and lung adenocarcinoma (excluding rs360206).Conclusion: Our findings reveal a relationship between ACE inhibition and lung cancer development, as well as a significant association between ACEI-induced cough and a higher risk of lung cancer for Europeans. Patients with hypertension who experience dry cough as a side effect of ACEI use should consider switching to an alternative antihypertensive treatment

    Controlling the thermoelectric properties of organo-metallic coordination polymers through backbone geometry

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    Poly(nickel-benzene-1,2,4,5-tetrakis(thiolate)) (Ni-btt), an organometallic coordination polymer (OMCP) characterized by the coordination between benzene-1,2,4,5-tetrakis(thiolate) (btt) and Ni2+ ions, has been recognized as a promising p-type thermoelectric material. In this study, we employed a constitutional isomer based on benzene-1,2,3,4-tetrakis(thiolate) (ibtt) to generate the corresponding isomeric polymer, poly(nickel-benzene-1,2,3,4-tetrakis(thiolate)) (Ni-ibtt). Comparative analysis of Ni-ibtt and Ni-btt reveals several common infrared (IR) and Raman features attributed to their similar square-planar nickel–sulfur (Ni–S) coordination. Nevertheless, these two polymer isomers exhibit substantially different backbone geometries. Ni-btt possesses a linear backbone, whereas Ni-ibtt exhibits a more undulating, zig-zag-like structure. Consequently, Ni-ibtt demonstrates slightly higher solubility and an increased bandgap in comparison to Ni-btt. The most noteworthy dissimilarity, however, manifests in their thermoelectric properties. While Ni-btt exhibits p-type behavior, Ni-ibtt demonstrates n-type carrier characteristics. This intriguing divergence prompted further investigation into the influence of OMCP backbone geometry on the electronic structure and, particularly, the thermoelectric properties of these materials
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