Hydrosilylation of Aldehydes and Ketones Catalyzed by Half‐Sandwich Manganese(I) N‐Heterocyclic Carbene Complexes

Easily available manganese(I) N‐heterocyclic carbene (NHC) complexes, Cp(CO)₂Mn(NHC), obtained in one step from industrially produced cymantrene, were evaluated as pre‐catalysts in the hydrosilylation of carbonyl compounds under UV irradiation. Complexes with NHC ligands incorporating at least one mesityl group led to the most active and selective catalytic systems. A variety of aldehydes (13 examples) and ketones (11 examples) were efficiently reduced under mild conditions [Cp(CO)₂Mn(IMes) (1 mol%), Ph₂SiH₂ (1.5 equiv.), hν (350 nm), toluene, 25 °C, 1–24 h] with good functional group tolerance.

     

Asymmetric Hydrosilylation of Prochiral Ketones Catalyzed by Nanocrystalline Copper(II) Oxide

Asymmetric hydrosilylation of aryl alkyl ketones to afford chiral secondary alcohols with good yields and excellent enantioselectivity is realized by using nanocrystalline copper(II) oxide and BINAP in the presence of organosilanes as the stoichiometric reducing agents.     

Efficient Esterification of Fatty Acids with Alcohols Catalyzed by Zr(SO4)2 · 4H2O Under Solvent-Free Condition

Zirconium sulfate (Zr(SO₄)₂ · 4H₂O) was an efficient catalyst for the esterification of fatty acids and alcohols under solvent-free condition. The esterification of fatty acid with branched alcohols using Zr(SO₄)₂ · 4H₂O catalyst gave a good yield of the corresponding ester. The zirconium sulfate Bronsted acid site was suggested to be the catalytically active species in this reaction. In addition, Zr(SO₄)₂ · 4H₂O compound is a potential green catalyst due to its high catalytic activity and low toxicity. This compound is also cost effective, easy to handle, is easily recovered by simple filtration and can be recycled for further reactions.     

Efficient Enantioselective Hydrosilylation of Aryl Ketones Catalyzed by a Chiral BINAP‐Copper(I) Catalyst‐Phenyl(methyl)silane System

The Cu(I)‐chiral diphosphine (BINAP) system was found to efficiently catalyze the hydrosilylation of aryl alkyl ketones with excellent enantioselectivities by using phenyl(methyl)silane as stoichiometric hydride source.     

Enhanced one-step purification of C2H4 from C2H2/C2H4/C2H6 mixtures by fluorinated Zr-MOF

The extraction of C₂H₄ from C₂H₆/C₂H₄/C₂H₂ mixtures is of great significance in the chemical industry for C₂H₄ production but the process remains challenging due to the similarity of these C₂ hydrocarbon species in their molecular size and physical properties. Here, we report the fluorination of a stable Zr-MOF, UiO-66, to fine-tune the pore dimensions and pore functionality. In particular, UiO-66-CF₃ shows notably preferential adsorption of C₂H₆ and C₂H₂ over C₂H₄, with C₂H₂/C₂H₄ and C₂H₆/C₂H₄ selectivities of 1.4 and 1.9, respectively. Theoretical calculations provide insight into the binding sites of UiO-66-CF₃ for C₂ hydrocarbon adsorption. Breakthrough experiments further confirmed the capability of the material for purification of C₂H₄ from C₂H₂/C₂H₄/C₂H₆ ternary mixtures, evidenced by the high purity C₂H₄ (99.9%+) obtained directly from outlet gas.     

Ti(SO4)2/C催化合成硬脂酸甲酯的研究

研究了Ti(SO4)2/C在硬脂酸与甲醇酯化中的催化性能，结果表明，Ti(SO4)2/C在该反应中具有很好的催化性能，并得到了合成硬脂酸甲酯的新工艺条件；催化剂用量（硬脂酸质量分数）为5％；醇酸摩尔比为6：1，反应温度70℃，反应时间3h，优化条件，硬脂酸的酯化率达98％。     

Fe2(SO4)3/膨润土固体酸催化剂催化萘异丙基化反应

通过对膨润土酸化处理得到活性白土,以活性白土为载体浸渍硫酸铁,可得到Fe2（SO4）3／膨润土固体酸催化剂：以Fe2（SO4）3/膨润土为催化剂,通过正交试验对萘的异丙基化反应工艺条件进行了考察,得到适宜的反应条件为：n（萘）／n（异丙醇）：1．8,n（萘）／n（十氢萘）=7．5,反应温度为260℃,反应时间为6h,催化剂用量为萘质量的12.5％,并各因素影响萘异丙基化反应结果进行了系统分析。此外,还对催化剂的酸强度、酸度和酸的类型进行了表征。     

Stereoselective Alkylations of Enolates Derived from Ligands Attached to the Indenyl Iron Chiral Auxiliary [(η5-C9H7)Fe(CO)(PPh3)]: X-ray Crystal Structure and Conformational Analysis of [(η5-C9H7)Fe(CO)(PPh3)COCH3]

The preparation, X-ray crystal structure, and conformational analysis of the acetyl complex [(η⁵ - C₉H₇)Fe(CO)(PPh₃)COCH₃] ( 5 ) are described. Deprotonation and alkylation of complex 5 generates the corresponding propanoyl ( 6 ) and butanoyl ( 7 ) complexes. Deprotonation and alkylation of complexes 6 and 7 to generate complementary diastereoisomers of the corresponding 2-methylbutanoyl complex occur with high stereoselectivities. The aldol reaction of the diethylaluminium enolate derived from 5 with acetaldehyde also shows a high stereoselectivity (95:5). The reactions of the indenyl complex 5 clearly parallel those for the cyclopentadienyl analogue and this is rationalised in terms of the conformational analysis.     

[Fe(C7H5O3)(C9H6NO)2]三元配合物的合成及抑菌性能

本文以水杨酸、8-羟基喹啉为配体与铁(Ⅲ)合成了三元配合物,用元素分析、红外光谱、紫外可见光谱、荧光光谱等手段对其进行表征,确定其化学组成为[Fe(C7H5O3)(C9H6NO)2]。其中水杨酸脱质子以羧酸根与Fe3+成键,酚羟基不参与配位,而8-羟基喹啉脱质子以酚羟基氧和杂环上的氮原子双齿配位,形成五元螯环。配合物在整个可见光区都有较强吸收,粉末及其浓溶液均呈黑色,稀溶液显紫色。以300 nm为激发波长时,三元配合物在409 nm处有较强的发射荧光。采用分光光度法研究其对大肠杆菌生长的作用,配合物摩尔浓度低于2 mmol/L时,促进大肠杆菌的生长,高于2 mmol/L时抑制其生长,浓度越大抑制作用越强,即配合物对大肠杆菌的生长具有双向生物效应。     

Tetra- and hexanuclear cage molecules based on diruthenium tetracarbonyl sawhorse units: Synthesis and molecular structure of [{Ru2(CO)4(PPh3)2}2(O2CCH2CO2)2] and [{Ru2(CO)4(PMe3)2}3(O2CC6H4CO2)3]

The thermal reaction of Ru₃(CO)₁₂ with malonic acid, followed by the addition of the corresponding ligand, yields the tetranuclear ruthenium complexes [{Ru₂(CO)₄L₂}₂(O₂CCH₂CO₂)₂] (L = PPh₃: 1, L = 3,5-Me₂NC₅H₃: 2), while the reaction of Ru₃(CO)₁₂ with terephthalic acid, followed by the addition of the corresponding ligand, gives rise to the formation of the hexanuclear ruthenium complexes [{Ru₂(CO)₄L₂}₃(O₂CC₆H₄CO₂)₃] (L = PMe₃: 3, L = 3,5-Me₂NC₅H₃: 4). The single-crystal X-ray structure analyses for 1 and 3, reveal both cages to consist of Ru₂(CO)₄ sawhorse units, 1 being a molecular loop, while 3 is a molecular triangle.     

[Fe(C7H5O3)(C9H6NO)2]三元配合物的合成及抑菌性能

以水杨酸、8-羟基喹啉为配体与铁(Ⅲ)合成了三元配合物,用元素分析、红外光谱、紫外可见光谱、荧光光谱对其进行表征,确定其化学组成为[Fe(C7H5O3)(C9H6NO)2]。其中,水杨酸脱质子以羧酸根与Fe3+成键,酚羟基不参与配位,而8-羟基喹啉脱质子以酚羟基氧和杂环上的氮原子双齿配位,形成五元螯环。配合物在整个可见光区都有较强吸收,粉末及其浓溶液均呈黑色,稀溶液呈紫色。以300 nm为激发波长时,三元配合物在409 nm处有较强的发射荧光。采用分光光度法研究其对大肠杆菌生长的作用,配合物浓度低于2 mmol/L时,促进大肠杆菌的生长,高于2 mmol/L时抑制其生长,浓度越大抑制作用越强,即配合物对大肠杆菌的生长具有双向生物效应。     

Two types of tetrasubstitution in [H4Ru4(CO)12]: spectroscopic characterization and crystal structure determination of [H4Ru4(CO)8(PMe2Ph)4] and [H2Ru4(CO)9(PMe2Ph)4]

Two tetrasubstituted tetranuclear ruthenium clusters containing dimethylphenylphosphine [H₄Ru₄(CO)₈(PMe₂Ph)₄] and [H₂Ru₄(CO)₉(PMe₂Ph)₄] were prepared and characterized spectroscopically as well as by X-ray crystallography. Both compounds show a structure based on the usual 60-electron tetrahedral framework with each ruthenium atom being bonded to one phosphine ligand. In the case of the nonacarbonyl derivative, one of the ruthenium atoms has one terminal carbonyl group and is also bonded to two semibridging carbonyl groups; two other metal–metal bonds are bridged by the hydride groups. In the case of the octacarbonyl compound all the ruthenium atoms are bonded to two terminal carbonyls and to two bridging hydrides. NMR spectroscopical information of [H₄Ru₄(CO)₈(PMe₂Ph)₄] suggests the presence of two isomers in solution which we propose to have D_2d and C_s symmetries. The observation of the NMR properties gives some observations about conditions that favour coupling between substituents in different ruthenium atoms.     

Reduction of n-C5H11N3 Catalyzed by [Mo2Fe6S8(OMe)3(SC6H4-p-n-C8H17)6]3– in an Aqueous Micellar Solution

Reduction of n-C₅H₁₁N₃ by Na₂S₂O₄ was performed in the presence of (n-Bu₄N)₃ [Mo₂Fe₆S₈(OMe)₃(SC₆H4-p-n-C₈H₁₇)₆] ((n-Bu₄N)₃ [Mo-Fe]) as a catalyst in aqueous Triton X-100 micellar solutions. The rate of the reduction is enhanced efficiently by the addition of methyl viologen (MV²⁺). The methyl viologen radical cation (MV⁺) produced by the reaction of MV²⁺ with Na₂S₂O₄ undergoes a disproportionation reaction to afford MV²⁺ and MV° in the micellar solution. The resultant MV° formed in the micelle transfers two electrons to [Mo-Fe]³⁻ effectively to give [Mo-Fe]⁵⁻, which reduces n-C₅H₁₁N₃ with two electrons to produce n-C₅H₁₁NH₂ and N₂.     

二氧化碳在CH4+CO2+N2/C2H6三元系中的结霜温度计算

含CO₂的天然气体系在历经低温工艺时,由于CO₂的三相点温度(216.55 K)较高,容易凝华结霜产生固体CO₂,因而有必要对CO₂在天然气中的结霜温度进行计算。根据气固相平衡原理,分别采用道尔顿分压定律、PR状态方程对CO₂在CH₄-CO₂-N₂和CH₄-CO₂-C₂H₆三元系中的结霜温度进行了计算。此外,还采用HYSYS软件对CO₂的结霜温度做了相应的计算。将3种方法的计算结果和实验结果进行了比较,结果表明3种方法在预测三元系中CO₂的结霜温度时,都具有良好的精度。其中,PR状态方程法和HYSYS法的精度略高于道尔顿分压定律法;道尔顿分压定律法虽精度最低,但计算最简单,且也能获得满意的精度,可做工程快速估算使用。     

[CoI2(C6H4N3CH2CO2C4H2SCO2CH2C6H4N3)], a coordination polymer containing the thiophene-2,5-di(carboxylatomethylenebenzotriazole) bridging ligand: synthesis,structure, redox properties

The title complex was obtained by reacting CoI₂ with thiophene-2,5-di(carboxylatomethylenebenzotriazole) in dichloromethane. The single-crystal X-ray structure analysis of the green material reveals a polymeric chain of CoI₂ units, tetrahedrally coordinated and connected by the 3-nitrogen atoms of the two benzotriazole groups of the multifunctional ligand. The paramagnetic cobalt(II) polymer can be oxidised by hexachloroethane to give the corresponding cationic cobalt(III) complex [CoI₂(C₆H₄N₃CH₂CO₂C₄H₂SCO₂CH₂C₆H₄N₃)(H₂O)₂]⁺ which is diamagnetic and precipitates as the green–yellow chloride salt.     

Photoluminescence and photochemistry of Pt(II)(PPh3)2(C6O6) induced by rhodizonate IL excitation

The complex Pt(II)(PPh₃)₂(C₆O₆) was prepared by the reaction of Ag₂C₆O₆ with cis-Pt(PPh₃)₂Cl₂ in acetonitrile. Pt(PPh₃)₂(C₆O₆) is characterized by a lowest-energy IL (rhodizonate) excited state. The complex shows an IL fluorescence, but is also photoactive. The photolysis leads to the conversion of rhodizonate to croconate in the coordinated state: Pt(II)(PPh₃)₂(C₆O₆) → Pt(II)(PPh₃)₂(C₅O₅) + CO.     

[(C_2H_5)_4N]_2｛Fe_4S_4[S_2CN(C_2H_5)_2]_4｝的晶体和分子结构

本文报导含类立方烷型簇核Ｆｅ４ｓ４的金硫配位化合物［（Ｃ２Ｈ５）４Ｎ］２｛Ｆｅ４Ｓ４［Ｓ２ＣＮ（Ｃ２Ｈ５）２］４｝的合成、晶体和分子结构测定的结果。     

六羰基钨催化制备聚苯乙炔及其荧光性能的研究

用W(CO) 6 催化体系聚合苯乙炔 ,以高产率获得较高相对分子质量的聚苯乙炔。使用UV、IR、GPC等分别对聚苯乙炔结构进行表征。采用不同波长的激发光对聚苯乙炔荧光性能进行了详细研究 ,结果表明 :当聚苯乙炔用 31 0nm激光激发时 ,呈现 3个荧光发光峰 ,峰值分别在348、396和 61 0nm处 ,与其溶液的紫外吸收有类似的光谱曲线特征。荧光峰在 348nm处的荧光 ,当聚苯乙炔质量浓度大于 0 0 5g L时 ,呈现荧光猝灭效应 ;在聚苯乙炔质量浓度为 1 0 - 4g L时 ,呈现出最大的荧光发光量子效率。当激发光波长低于 2 70nm和高于 340nm时 ,348nm波长荧光消失 ;荧光峰在 396nm处的荧光 ,当聚苯乙炔的质量浓度为 1 0 - 2 g L时 ,呈现最大的发光量子效率 ,聚苯乙炔的质量浓度增大或降低 ,其发光强度均呈现减弱现象 ;荧光峰在 61 0nm的荧光 ,在聚苯乙炔质量浓度为 1 0 - 4g L时 ,呈现最大的发光量子效率。荧光性能研究结果证明这种催化剂获得的聚苯乙炔具有多种异构链结构。