Dichlorido(2-chloro-9-mesityl-1,10-phenanthroline-κ2 N,N′)cobalt(II) dichloro­methane hemisolvate

The title compound, [CoCl2(C21H17ClN2)]·0.5CH2Cl2, crystallizes from dichloro­methane as a 2:1 solvate [CoCl2L]2·CH2Cl2 (L is 2-chloro-9-mesityl-1,10-phenanthroline). There are two independent CoCl2 L mol­ecules in the asymmetric unit and both mol­ecules have similar conformations. They are connected by a weak C—H⋯π inter­action involving the mesityl ring. The cobalt center is four-coordinated by the two N-atom donors of the bidentate ligand and two chloride ions in a distorted tetra­hedral geometry. The packing of the mol­ecules is stabilized by weak slipped π–π stacking inter­actions between symmetry-related phenanthroline groups

2-(2,4,6-Trimethyl­phen­yl)-1,10-phenanthroline

In the title mol­ecule, C21H18N2, the mean plane of the benzene ring of the mesityl group forms a dihedral angle of 82.69 (4)° with that of the phenanthroline ring system. The crystal structure is stabilized by π–π stacking inter­actions between the phenanthroline system and the benzene ring of the mesityl group of a symmetry-related mol­ecule, with centroid–centroid distances of 3.7776 (14) and 3.7155 (13) Å

Numerical Study on the Characteristics and Control Method of Coal Leakage between Supports in Integrated Mining of Extremely Loose and Soft Coal Seams

Extremely loose and soft coal seams, with a Platts coefficient of less than 0.3, are easy to break in the process of integrated mechanized roof coal mining and are prone to spilling and piling up between the hydraulic supports, which is a safety hazard for the movement of equipment. The coal particles must be cleaned up manually, resulting in reduced resource recovery rates and lower mining face efficiency. To effectively mitigate and control the problem of coal spillage accumulation amidst hydraulic supports, this study utilizes discrete element numerical simulation to examine the characteristics of block size distribution and the spilling process during the crushing of highly loose and soft top coal. By taking into account various parameters associated with shelf spacing, this research identifies key factors for controlling arching and self-stopping phenomena in top coal particles. The study findings suggest that the uppermost coal layer undergoes significant fragmentation during the integrated mining process of loosely packed and soft coal seams, resulting in a higher probability of coal leakage issues observed near the rack’s coal wall side and at the end of the roof control area. The key factors contributing to the self-arresting of spilled coal particles include inherent characteristics of the coal body, particle diameter, and stand spacing. In this specific mine under investigation, an arch formation naturally occurs to prevent further leakage when the distance between stands is less than eight times the diameter of particles, and after process correction, the average time saving for a single shift of manual floating coal cleaning at the working face is about 2 h, and the proportion of time saving is more than 50~75%

Support-surrounding rock relationship and top-coal movement laws in large dip angle fully-mechanized caving face

When mining the fully-mechanized longwall caving face along strike, the unstable equipment, the low top-coal recovery ratio and the difficulty in controlling surrounding rock may occur due to large dip angle. Considering the effects of strike angle on support stability, the “support-surrounding rock” mechanical models of support topple and support slip were established in this paper. On the basis, the influencing factors of support stability were analyzed and the technical measures of controlling support and surrounding rock stability were put forward. Then the loose particles simulation experiment was conducted to analyze the impacts of caving directions and methods on the top-coal recovery in large dip angle fully-mechanized caving face. Finally, the “upward sequence and double-openings double-rounds” caving technology was determined. The research results are of great scientific significance and practical values to improve large dip thick seam mining technology. Keywords: Large dip angle, Thick seam, Fully-mechanized caving, Working resistance, Top-coal movemen

Reductive cyanation of organic chlorides using CO2 and NH3 via Triphos–Ni(I) species

Nitriles are key intermediates in production of pharmaceuticals, agrochemicals and organic materials. Here, the authors report a nickel-catalyzed reductive cyanation of organic chlorides with CO2/NH3 and urea as cyanation reagents to afford a broad range of organic nitriles

Characteristics of Perimeter Rock Damage in a Bottom-Pumping Roadway under the Influence of Mining Activities and Rational Location Studies: A Case Study

With the aim of determining the damage characteristics and a reasonable positional arrangement of the surrounding rock in a bottom-pumping roadway influenced by mining in a high-gas mine, the boundary equation for the plastic zone of the surrounding rock in a circular roadway under an unequal compressive stress field was adopted to analyze the relationship between the distribution characteristics of the plastic zone of the bottom-pumping roadway and the stability of the rock surrounding the bottom-pumping roadway under different bidirectional stress ratios. This was carried out in the bottom-pumping roadway of the working face of Licun coal mine 3301 as the engineering background, where the nature of the coal seams mined is bituminous coal, and the absolute gas outflow is 0.5 m3/min−1. A numerical simulation was used to analyze the distribution characteristics of the surrounding rock stress and the bidirectional stress ratio, as well as the deformation and damage characteristics of the surrounding rock at different positions in the bottom-pumping roadway. A numerical simulation was applied to analyze the distribution characteristics of the surrounding rock stress and the two-way stress ratio, as well as the deformation and damage characteristics of the rock surrounding the bottom-pumping roadway when the bottom-pumping roadway was arranged in different locations. The results show that, with an increase in the bidirectional stress ratio, the plastic zone of the perimeter rock in the bottom-pumping roadway shows nonuniform “butterfly” distribution characteristics, which seriously affects the stability of the rock on the perimeter of the roadway; the stress on the bottom plate of the working face after excavation can be divided into four areas according to the size of the bidirectional stress ratio and the stress loading and unloading states. In addition, the size of the perimeter rock deformation can be sorted into four areas according to the damage range of the perimeter of the rock plastic zone in the bottom-pumping roadway. The size of the deformation in the surrounding rock can be sorted as follows: unpressurized high-stress ratio > unpressurized stress ratio stable area > pressurized low-stress ratio area > original rock stress ratio area. Accordingly, we found that the reasonable location of the bottom-pumping roadway is arranged at the 15 m position outside the hollow area below the coal pillar, along the limestone upper medium-grained sandstone layer along the bottom. The study’s results were applied to the field. The industrial experiments on the site show that the deformation of the surrounding rock is reasonable when the bottom-pumping roadway is dug along the limestone roof and arranged 15 m outside the fault of the mining hollow area below the coal pillar

Syntheses and Structures of Mononuclear, Dinuclear and Polynuclear Silver(I) Complexes of 2‑Pyrazole-Substituted 1,10-Phenanthroline Ligands

A series of mononuclear, dinuclear and polynuclear silver­(I) complexes (<b>1</b>–<b>6</b>) bearing 2-pyrazole-substituted 1,10-phenanthroline derivatives (<b>L</b>^<b>1</b>, ^<b>F</b><b>L</b>^<b>1</b>, <b>L</b>^<b>2</b>) have been synthesized and characterized by ¹H and ¹³C NMR, IR spectroscopy, elemental analysis, and single crystal X-ray diffraction. Reaction of <b>L</b>^<b>1</b> (<b>L</b>¹ = 2-(3,5-dimethylpyrazol-1-yl)-1,10-phenanthroline) with AgClO₄ or AgBF₄ afforded two dinuclear silver­(I) complexes [Ag₂(<b>L</b>^<b>1</b>)₂(CH₃CN)₂]­(ClO₄)₂ (<b>1</b>) and [Ag₂(<b>L</b>^<b>1</b>)₂(CH₃CN)₂]­(BF₄)₂ (<b>2</b>), in which two [Ag<b>L</b>^<b>1</b>(CH₃CN)]⁺ units are linked by Ag···Ag interaction (Ag···Ag separation: 3.208(2) and 3.248(1) Å, respectively). A one-dimensional polymer {[Ag<b>L</b>^<b>1</b>]­(BF₄)}_∞ (<b>3</b>) consisting of an infinite ···Ag···Ag···Ag··· chain (Ag···Ag separation: 3.059(1) Å), as well as a dinuclear complex [Ag₂(ClO₄)₂(<b>L</b>^<b>1</b>)₂] (<b>4</b>) in which the perchlorate anions instead of solvents are involved in the metal coordination, have also been obtained. The mononuclear complex [Ag­(^<b>F</b><b>L</b>^<b>1</b>)₂]­(BF₄) (<b>5</b>) was synthesized from ^<b>F</b><b>L</b>^<b>1</b> (^<b>F</b><b>L</b>^<b>1</b> = 2-(3,5-bis­(trifluoromethyl)­pyrazol-1-yl)-1,10-phenanthroline) and AgBF₄, while the dinuclear [Ag₂(BF₄)₂(<b>L</b>^<b>2</b>)₂] (<b>6</b>) was isolated from <b>L</b>^<b>2</b> (<b>L</b>^<b>2</b> = 2-[<i>N</i>-(3-methyl-5-phenylpyrazole)]-1,10-phenanthroline). The photoluminescence properties of the ligands and complexes <b>1</b>–<b>6</b> have been studied both in the solid state and in solution

Metformin ameliorates liver fibrosis induced by congestive hepatopathy via the mTOR/HIF-1α signaling pathway

Introduction and Objectives: Congestive hepatopathy (CH) is a hepatic vascular disease that results in chronic liver congestion, which can lead to liver fibrosis. New uses of metformin have been discovered over the years. However, the function of metformin in congestive liver fibrosis is not yet fully understood. This study aimed to investigate the effect of metformin on liver fibrosis in a mouse model of CH. Materials and Methods: Partial ligation of the inferior vena cava (pIVCL) was used to establish a mouse model of liver congestion. Metformin (0.1%) was added to the daily drinking water of the animals, and the effect of metformin on liver tissue was studied after 6 weeks. Hepatic stellate cells (HSCs) were also stimulated with CoCl2 to investigate the inhibitory impact of metformin on the mammalian target of rapamycin (mTOR)/hypoxia-inducible factor-1α (HIF-1α) pathway. Results: Metformin attenuated liver congestion; decreased the expression of collagen, fibronectin, α-smooth muscle actin (α-SMA), and HIF-1α; and ameliorated liver fibrosis in pIVCL mice. The proliferation and migration of HSCs were inhibited by metformin in vitro, which prevented α-SMA expression and restrained HSC activation. The expression levels of phosphorylated-mTOR, HIF-1α, and vascular endothelial growth factor were also decreased. Conclusions: Metformin inhibits CH-induced liver fibrosis. Functionally, this beneficial effect may be the result of inhibition of HSC activation and of the mTOR/HIF-1α signaling pathway

Homometallic Silver(I) Complexes of a Heterotopic NHC-Bridged Bis-Bipyridine Ligand

By varying the metal to ligand ratio, stepwise formation of a series of homonuclear silver­(I) complexes of a carbene-bridged bis-bipyridine ligand (L) was achieved. In the mononuclear 1:2 complex [AgL₂]Br (<b>1</b>) only the carbene carbon is involved in the metal coordination, while both of the 2,2′-bipyridine (bpy) arms are free. When the amount of silver­(I) ion was increased, isomorphous 2:2 dinuclear complexes with different counteranions, [Ag₂L₂]­X₂ (X = Br^– (<b>2a</b>), PF₆^– (<b>2b</b>), BPh₄^– (<b>2c</b>)), were synthesized from the ligand LX, in which the carbene carbon and one of the bpy units participate in the coordination with silver­(I) ions. Further addition of Ag^I salt afforded the one-dimensional coordination polymer {[Ag₃L₂]­(PF₆)₃·4CH₃CN}_<i>n</i> (<b>3</b>), wherein the hanging bipyridine units also coordinate with Ag^I and thus all the coordination sites of the ligand are employed. The results reveal the preference of Ag^I ion for the carbene carbon donor rather than the bpy units. The synthesis, structures, and interconversion of the complexes and the counteranion effects on the structures are reported, and the luminescent properties of the ligand LX and the silver complexes have also been studied