Synthesis and Structure of Dimolybdenum(I) Carbonyl Compound with Thiolate and Carboxylate Mixed-tri-bridging Ligands [Bu_4N][Mo_2(CO)_6(SC_6H_4Cl-p)_2(CF_3COO)]

1 INTRODUCTION Molybdenum(I) compounds, in particular Mo(I)-SR compounds, are rare amongst numerous Mo compounds. So far, only the following compounds [Mo2(CO)8-n(SR)2(CH_3CN)n] (R = C6H5, CH_2CO2Et, n = 0, 2)[1～5] have been reported in the literature. Recently, we make an effort to develop investigations on Mo(I) compounds on the basis of preparing new Mo(I) compounds by introducing different functional ligands into Mo2(SR)2(CO)8, then determining their structures and measur…     

Synthesis and Structure of Dimolybdenum Carbonyl Thiolate Compound [Et4N]2[Mo2（CO）8（SC6H4—CH3—m）2]

1 INTRODUCTION In 1984, thiolate ligand was successfully introduced into molybdenum carbonyl compound by the reaction of Mo(CO)6 with [Et4N]SR( R = C6H5, But) in a moderate condition[1]. From then on, a series of dinuclear molybdenum(0) carbonyl thiolate compounds have been synthesized and characterized by using a variety of thiolate ligands in our research group. It was found that a planar Mo2S2 unit is in the compound [Et4N]2[Mo2(CO)8(SC6H4-CH_3-p)2][2] (2) and a "butterfly" t…     

Preparation of CaCO3/Polystyrene Inorganic/Organic Composite Nanoparticles

CaCO₃/polystyrene inorganic/organic composite nanoparticles (50 nm) with a core/shell structure were synthesized in 80% yield by emulsion polymerization. Nanometer CaCO₃ was pretreated with γ‐methacryloxypropyltrimethoxysilane in order to introduce polymerizable groups onto its surface. Soxhlet extraction experiments have shown that only 4% of total encapsulating polystyrene (PS) was removable when the ratio of CaCO₃ to styrene was relatively low (14.8–29.6%), indicating strong adhesion between CaCO₃ and PS.     

New Suberato‐bridged Supramolecular Layers: Crystal Structure of [Cu2(phen)2(C8H12O4)2] · 3 H2O with phen = 1,10‐phenanthroline

The reaction of CuCl₂ · 2 H₂O, 1,10‐phenanthroline (phen), suberic acid and Na₂CO₃ in a CH₃CN–H₂O solution yielded blue needle‐like crystals of [Cu₂(phen)₂(C₈H₁₂O₄)₂] · 3 H₂O. The crystal structure (monoclinic, P2₁/n, a = 10.756(2) Å, b = 9.790(2) Å, c = 18.593(4) Å, β = 91.15(3)°, Z = 2, R = 0.043, wR² = 0.1238) consists of suberato‐bridged [Cu₂(phen)₂(C₈H₁₂O₄)_4/2] layers and hydrogen bonded H₂O molecules. The Cu atoms are coordinated by two N atoms from one bidentate chelating phen ligand and three carboxyl O atoms from different suberato ligands to form distorted [CuN₂O₃] square‐pyramids with one carboxyl O atom at the apical position (d(Cu–N) = 2.017(2), 2.043(3) Å, basal d(Cu–O) = 1.936(2), 1.951(2) Å and axial d(Cu–O) = 2.389(2) Å). Two [CuN₂O₃] square‐pyramids are condensed via a common O–O edge to a centrosymmetric [Cu₂N₄O₄] dimer with the Cu…Cu distance of 3.406(1) Å indicating no interaction between Cu atoms. The resultant [Cu₂N₄O₄] dimers are interlinked by the tridentate suberato ligands to form [Cu₂(phen)₂(C₈H₁₂O₄)_4/2] layers parallel to (101). These are assembled via π‐π stacking interactions into 3D network with H₂O molecules in the tunnels extending in the [010] direction.     

Synthesis and Crystal Structure of [Cu2(H2O)2(phen)2(OH)2][Cu2(phen)2(OH)2(CO3)2] · 10 H2O with phen = 1,10‐phenanthroline

The blue copper complex [Cu₂(H₂O)₂(phen)₂(OH)₂][Cu₂(phen)₂(OH)₂(CO₃)₂] · 10 H₂O, which was prepared by reaction of 1,10‐phenanthroline monohydrate, CuCl₂ · 2 H₂O and Na₂CO₃ in the presence of succinic acid in CH3OH/H₂O at pH = 13.0, crystallized in the triclinic space group P1 (no. 2) with cell dimensions: a = 9.515(1) Å, b = 12.039(1) Å, c = 12.412(2) Å, α = 70.16(1)°, β = 85.45(1)°, γ = 81.85(1)°, V = 1323.2(2) ų, Z = 1. The crystal structure consists of dinuclear [Cu₂(H₂O)₂(phen)₂(OH)₂]²⁺ complex cations, dinuclear [Cu₂(phen)₂(OH)₂(CO₃)₂]^2– complex anions and hydrogen bonded H₂O molecules. In both the centrosymmetric dinuclear cation and anion, the Cu atoms are coordinated by two N atoms of one phen ligand, three O atoms of two μ‐OH groups and respectively one H₂O molecule or one CO₃^2– anion to complete distorted [CuN₂O₃] square‐pyramids with the H₂O molecule or the CO₃^2– anion at the apical position (equatorial d(Cu–O) = 1.939–1.961 Å, d(Cu–N) = 2.026–2.051 Å and axial d(Cu–O) = 2.194, 2.252 Å). Two adjacent [CuN₂O₃] square pyramids are condensed via two μ‐OH groups. Through the interionic hydrogen bonds, the dinuclear cations and anions are linked into 1D chains with parallel phen ligands on both sides. Interdigitation of phen ligands of neighboring 1D chains generated 2D layers, between which the hydrogen bonded water molecules are sandwiched.     

化学让生活多姿多彩——记中国科学技术大学化学科普活动

用"化学让大自然丰富多彩、色彩斑斓——天然色素的五彩世界""化学很魔幻——揭秘化学小魔术""化学让我们生活得更智慧、更安全、更健康——引导大众消除生活误区""化学也诗意——以诗入‘化’——打造诗意化学科普"和"化学让大自然更为奇特绝妙——走进大自然,学习化学知识,感悟化学的魅力"五个主题,介绍了中国科学技术大学化学实验教学中心在化学科普教育内容方面的一些探索和经验。     

Liquid-phase oxidation of toluene to benzaldehyde with molecular oxygen catalyzed by copper nanoparticles supported on graphene

Highly-dispersed copper nanoparticles (Cu NPs) were fabricated on the surface of reduced graphene oxide via direct hydrazine hydrate reduction of Cu²⁺ in aqueous solution. Scanning electron microscope and transmission electron microscope images show that the Cu NPs are distributed on the surface of graphene nanosheets, and the average particle size was about 40 nm. The Cu NPs supported on graphene have high reaction activity for the oxidation of toluene to corresponding benzaldehyde. It was found that the selectivity reached 66.5% and the conversion of toluene reached 11.5%.     

Recent advances in the functionalization of allenes via radical process

This review is focused on the recent advances in the functionalization of allenes via radical process. Different radical partners including carbon radicals and heteroatom radicals are discussed in the reactions of allenes. Generally, the radical formed in situ would attack the allene at the central carbon leading to allyl radical intermediate. However, the formation of alkenyl radical intermediate from allene could be observed as well in some cases with high regioselectivity and stereoselectivity.     

A Simple,Low-cost Method to Fabricate Drag-reducing Coatings on a Macroscopic Model Ship

A low-cost method was used to fabricate superhydrophobic coatings on a macroscopic model ship and the drag-reducing effect was investigated at both low and high speed. Hierarchical structures of the superhydrophobic copper coatings were characterized by means of scanning electron microscopy(SEM) and X-ray diffraction(XRD). Drag coefficient tests on surfaces with different wettability(superhydrophilic, hydrophilic, hydrophobic and superhydrophobic surfaces) showed that the as-prepared superhydrophobic surface exhibited a high remarkable drag reduction of 81% at a low speed of 1 mm/s. In the drag-reducing tests with model ship, the superhydrophobic coatings also exhibited around 16% drag reduction at a velocity of 0.3 m/s.     

Spatiotemporal Utilization of Latent Heat in Erythritol-based Phase Change Materials as Solar Thermal Fuels

Solar thermal fuels (STFs) have been particularly concerned as sustainable future energy due to their impressive ability to store solar energy in chemical bonds and controllably release thermal energy. However, currently studied STFs mainly focus on molecule-based materials with high photochemical activity, toxicity, and compromised features, which greatly restricts their applications in practical scenarios of solar energy utilization. Herein, we present a novel erythritol-based composite phase change material (PCM) as a new type of STFs with an outstanding capability to store solar energy as latent heat in its stable supercooling state and release thermal energy as needed. This composite PCM with stored thermal energy can be maintained stably at room temperature and subsequently release latent heat as high as 224.9 J/g during the crystallization process triggered by thermal stimuli. Remarkably, solar energy can be converted into latent heat stored in the composite PCM over months. Through mechanical stimulations, the released latent heat can increase the temperature of the composite up to 91 °C. This work presents a new concept of using spatiotemporal storage and release of latent heat in PCMs for solar energy utilization, making it a potential candidate as STFs for developing future clean energy techniques.