Ligand Configuration-Induced Manganese(II) Coordination Polymers: Syntheses, Crystal Structures, Sorption, and Magnetic Properties.

Three new coordination polymers, {[Mn3(pzbtz)2(Cl)2(H2O)2]·4H2O}n (1), {Mn2(pzbtz)(SO4)(H2O)3]·3H2O}n (2), and {[Mn3(pzbtz)3(H2O)3]·1.5DMA·2H2O}n (3), have been solvothermally synthesized with MnCl2/MnSO4 and a bitriazole ligand, 5'-(pyrazin-2-yl)-2H,4'H-3,3'-bi(1,2,4-triazole) (H2pzbtz), in different solvent systems. H2pzbtz shows different geometrical configurations and coordination modes, leading to the diverse three-dimensional (3D) frameworks of 1-3. Complex 1 contains the trinuclear Mn3(tr)4X2 (X = Cl or H2O) clusters and reveals an unobserved (3,4,8)-connected sqc929 topological framework with two types of cages. Complex 2 is a new (3,4,6)-connected network based on dinuclear Mn2(tr)2 clusters, and 3 shows an 8-connected bcu topology with a novel tetranuclear Mn4(tr)6 cluster. Complexes 1 and 2 show antiferromagnetic properties, while 3 reveals spin-canting magnetic behavior with an uncommonly high Tc around 44 K. In addition, 1 also possesses good adsorption selectivity for CO2 over CH4 and N2 and an uncommon gate-opening phenomenon.

Solvent or temperature induced diverse coordination polymers of silver(I) sulfate and bipyrazole systems: syntheses, crystal structures, luminescence, and sorption properties.

Three new coordination polymers, [Ag4(H2bpz)4(SO4)2]·H2O (1), [Ag2(H2bpz)2(SO4)]·3H2O (2), and [Ag3(H2bpz)4](SO4)2/3(OH)5/3·4H2O (3) have been solvothermally synthesized with Ag2SO4 and flexible ligand 3,3',5,5'-tetramethyl-4,4'-bipyrazole (H2bpz) in different solvents and temperatures. Complex 1 is a 2-fold interpenetrated three-dimensional (3D) framework with an uncommon (3,5)-connected hms topology. Complex 2 is a structural isomer of 1 and shows a three-connected 2D ths net consisting of interesting 3-fold and 2-fold heterochiral helical chains. Complex 3 discloses a grid layer structure, containing heterochiral helical chains and an unusual meso-helix. More interestingly, three sets of layers in 3 stack in different directions, affording an unprecedented 2D + 2D + 2D → 3D polycatenating cationic framework with 1D + 3D porous systems. In 1-3, H2bpz exhibit exobidentate bridging fashions with wide-ranged interpyrazole tilting angles and changeable coordination configurations, such as cis and trans fashions in 1 and 3 and uniform trans fashion in 2. These lead to the isomeric [Ag(H2bpz)]n arrays of wavelike and helical chains in 1 and 2, respectively. Complexes 1-3 display solid-state photoluminescence stemming from the ligand-centered fluorescent emissions of H2bpz. Because of the highly polar framework, 3 shows excellent adsorption selectivity for CO2 over N2.

Egg consumption and risk of type 2 diabetes mellitus in middle and elderly Chinese population: An observational study.

Data on the association between egg consumption and the risk of type 2 diabetes mellitus (T2DM) in the Chinese population are scarce. In the present study, we aimed to examine the association between egg consumption and the risk of T2DM in a middle and elderly Chinese population. A total of 3298 subjects (1645 men and 1653 women) from the Nutrition and Health Survey (2015-2017) in Hangzhou city were selected for the final analysis. Egg consumption was assessed using a validated food frequency questionnaire. All biochemical data and anthropometric measurements were collected following standardized procedures. Multivariable logistic regression analyses were used to assess the association between egg consumption and the risk of T2DM and the results were presented as odds ratios and 95% confidence interval (CI). Restricted cubic spline combined with logistic regression was used to explore the dose-response relationship between egg consumption and T2DM. Among 3298 subjects, 693 (21.0%) people had T2DM. Compared with participants who did not consume egg per week, the multivariable-adjusted odds ratios were 0.97 (95%CI : 0.78-1.21), 1.08 (95%CI : 0.91-1.06), 1.20 (95%CI : 0.94-1.55), 1.27 (95%CI : 0.99-1.68) in men (P > .05); 1.06 (95%CI : 0.81-1.37), 0.97 (95%CI : 0.78-1.21), 1.26 (95%CI : 0.99-1.59), 1.19 (0.92-1.54) in women (P > .05); 0.89 (95%CI : 0.79-1.04), 0.98 (95%CI : 0.91-1.06), 1.06 (95%CI : 0.87-1.30), 1.09 (95%CI : 0.88-1.34) in both men and women for egg consumption 0∼7, 7, 7∼14, and ≥14 eggs/week, respectively (P > .05). The dose-response curve showed that, with the increase of egg consumption, the risk of T2DM first increased and then decreased (P = .027).We found that the association between egg consumption and T2DM was nonlinear, and higher egg consumption was not associated with an elevated risk for T2DM in middle-aged and elderly Chinese. However, future prospective studies are needed to confirm these findings.

Structural diversity of five new bitriazole-based complexes: luminescence, sorption, and magnetic properties.

Employing an uninvestigated eight N-donor bitriazole ligand, 5'-(pyrazin-2-yl)-2H,4'H-3,3'-bi(1,2,4-triazole) (H2pzbtz), five complexes, {[Zn2(pzbtz)(SO4)(H2O)2]·2H2O}n (), {[Cd(pzbtz)]·3H2O}n (), [Zn3(Hpzbtz)2(SO4)2(H2O)6] (), [Co(Hpzbtz)2(H2O)2] () and {[Co2(pzbtz)2(H2O)2]·4H2O}n (), have been solvothermally synthesised by altering the reaction solvents and temperatures. Complex shows a three-dimensional (3D) framework with a very rare (3,5)-connected fsc-3,5-Cmce-2 topology. Complex exhibits a (4,4)-connected 3D pts framework with 1D channels. Complexes and are discrete trinuclear and mononuclear molecules, respectively. Complex presents a chiral 3D framework based on a novel trinuclear Co3(tr)4 cluster and features an unusual six-connected lcy topology. In the five complexes, H2pzbtz show a very variety of geometrical configurations and coordination modes. Due to the planarity of H2pzbtz, complexes display strong photoluminescence; in particular, features highly selective luminescent sensing for the Cu(2+) ion and nitrobenzene molecule. In addition, shows highly selective adsorption for CO2 over CH4, and exhibits antiferromagnetic exchange interactions among the Co(2+) ions.

A 3D porous metal-organic framework containing nanotubes based on multiple helices.

Combining Co2 clusters with mixed H2bpdc and H2bpz ligands creates an unprecedented 3-fold interpenetrated 5-connected porous framework, which possesses the fascinating double-walled nanotubes structure assembled from nonuple and triple helices, and exhibits gas sorption properties.