Ab initio Studies on Intermolecular Interaction of Formamide and Hydroxyacetonitrile Dimers

The structures,the binding energies and the thermodynamic properties of formamide and hydroxyacetonitrile(HAN) dimers have been studied by means of the self\|consistent \%ab initio\% Hartree\|Fock and the second\|order Mφller\|Plesset correlation energy correction methods. The counterpoise procedure was used to check the basis set superposition error(BSSE) of the binding energies. There exist cyclic structures in a formamide dimer(Ⅰ),a HAN dimer(Ⅱ) and their heterodimer(Ⅲ). The corrected binding energies for dimers Ⅰ,Ⅱ and Ⅲ are respectively -45.53,-45.83 and -43.89 kJ/mol at the MP2/aug\|cc\|p VDZ//HF/\{aug\|cc\|p VDZ\} level. The change of the Gibbs free energies(Δ\%G\%) in the process of Ⅰ+Ⅱ→2Ⅲ was predicted to be -2.74 kJ/mol at 298.15 K. Dimer Ⅲ can be spontaneously produced in the mixture of formamide and HAN,which is in agreement with the experimental fact that most cyanohydrins are capable of interacting with dipeptide cyclo\|His\|Phe(CHP).

The diffusion and concentration effects of formamide on a TiO₂surface in the presence of a water solvent

The formamide-titanium oxide interaction mechanism is a research target of great importance for understanding the elementary events of the origin of life: the synthesis of nucleoside bases and formation of biological molecules needed for life. Titanium oxide (TiO2) can act as a strongly adsorbing surface or a catalytic material. In the present study, a comparative molecular dynamics analysis performed to clarify the adsorbing and diffusion properties of liquid formamide on a TiO2 surface in the presence of water molecules. The structural features of the formamide concentration effect (the accumulation of molecules) on a TiO2 surface in the presence and absence of water solvent are cleared up. Modification of the formamide diffusion abilities mediated by a water solvent is observed to correlate with the formamide-water concentration distribution on the surface.

Theoretical Study on the Tautomerization Reaction of Formamide to Formamidic Acid Encapsulated in a Nano-sized Molecular Container

The hybrid calculations with ONIOM（B3LYP/6-31G＊：AM1） method were carried out on the tautomerization reaction of formamide to formamidic acid in the microcontainer-encapsulated state. The free-state tautomerization process was also investigated with B3LYP/6-31G＊＊//B3LYP/6-31G＊ method for the purpose of comparison. Bare tautomerization, H20-assisted（single-H20 or multiple-HaO） and self-assisted mechanisms were all taken into consideration for the encapsulated state. The results show that only bare tautomerization and single-H2O catalysis mechanisms are possible to the encapsulated formamide tautomerization owing to the container＇s size confinement effect. Geometrical changes in the complexed container and guest molecules are discussed to deeply understand the complex＇s structural properties. The bare tautomerization barrier in the encapsulated state increases by 23.826 kJ/mol, accounting for 12% of the corresponding total energy barrier in the free state, and the increased values for the single-H2O catalysis process are 12.958 kJ/mol, accounting for 16% of the corresponding total energy barrier, respectively. This finding suggests that the encapsulation can make the tautomerization process slightly difficult.

Ab initio Study on the Tautomerization Mechanism and the Kinetics of Formamide

The tautomerism of formamide has been investigated by ab initio calculation using RHF/4-31G basis set. The change in some physical properties along the reaction path is presented. In the study of molecular reaction kinetics, we have calculated all the kinetic parameters according to statistical thermodynamics and transition state theory. The combination of kinetics analysis with IRC analysis has indicated that the tautomerism is concerted but the geometric changes are nonsynchronous; the lifetime of the transition state is short and the transition state is tight type; the formamide is more stable than formimidic acid; the kinetic rate constant of backward reaction is larger than that of the forward reaction in the range of temperature studied.

Theoretical Study on the Self, Water-assisted and Au-to-assisted Dimer Proton Transfer Reaction in the N-Hydroxy-Methylen-Formamide

The proton transfer in the isolated, mono and dehydrated forms, isolated dimers of N-Hydroxy Methylen Formamide (NHMF) have been completely investigated in the present study using Density Functional Theory (DFT), M?ller-Plesset perturbation (MP2) and Hartree-Fock (HF) methods with the 6-31G* and 6-311G* basis sets. The barrier heights for both H2O-assisted and auto-assistance reactions are significantly lower than that of the bare tautomerization reaction from NHMF to N-Formyl Formamide (NFF), implying the importance of the superior catalytic effect of H2O in the monomer of NHMF and important role of HOCH= N-COH for the intramolecular proton transfer.

Pyrolysis-free formamide-derived N-doped carbon supporting atomically dispersed cobalt as high-performance bifunctional oxygen electrocatalyst

Non-precious metal-nitrogen-carbon(MNC)electrocatalysts have gained tremendous attention as promising electrocatalysts for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).However,the most applicable strategies for the synthesis of MNC materials heavily rely on pyrolysis treatment,which may easily lead to metal aggregation and subsequent degradation of catalytic performance.Herein,we developed a pyrolysis-free strategy for preparing MNC materials,which was demonstrated by achieving ultrathin cobalt-nitrogen-carbon(Co NC)layer with dense atomically dispersed cobalt sites depositing on graphene oxide(GO)via simple treatment of Co salt and GO in formamide.The formamide-derived Co NC layer deposited on GO(termed as f-Co NC/GO)could be controlled in 1-2 nm thick.Remarkably,the f-CoNC/GO composite without pyrolysis exhibited excellent bifunctional performance toward ORR and OER,which was attributed to the dense atomically dispersed Co-Nxsites and improved conductivity by GO substrate.Furthermore,the f-CoNC/GO-assembled rechargeable Zn-air battery showed highly efficient and stable performance,demonstrating our pyrolysis-free method to be straightforward,cost-effective,and feasible for the scalable production of MNC electrocatalysts.

New Method for Synthesis of Formamide from CO_2

The research team headed by Ding Kuiling working in the State Key Laboratory of Metallorganic Chemistry at the CAS Shanghai Institute of Organic Chemistry by using the princer type ruthenium complex catalyst has successfully developed a new method for effectively synthesizing formamide compounds from CO_2,H2 and primary or secondary amines serving as the feedstocks.

碱/尿素预处理的纤维素纤维塑化改性处理研究

本研究采用碱/尿素体系在不同温度下分别对阔叶木浆、针叶木浆和竹浆纤维进行润胀预处理,并通过四因素三水平正交实验,探究了甘油、甲酰胺和柠檬酸三乙酯3种塑化剂在不同塑化温度、塑化剂质量分数及塑化时间下对纤维的塑化改性效果。结果表明,在10℃下,碱/尿素体系预处理的针叶木浆纤维具有最高的润胀程度,有利于进一步塑化改性处理;本实验的最佳塑化改性处理条件为:甲酰胺质量分数30%,塑化温度25℃,塑化时间5 h。在该条件下制备的塑化纤维有望在特定领域作为塑料的替代材料。

危险化学品重大危险源辨识中的疑难分析

以某企业二甲基甲酰胺(DMF)项目为例,分析探讨危险化学品建设项目重大危险源辨识过程中的疑难问题及疏漏:如单元划分、混合物临界值取值、实际存在量(在线量)如何确定等问题,以供安全评价机构、设计单位、政府安全监督管理部门的相关人员参考。

基于液相色谱法的鞋用发泡材料甲酰胺和偶氮二甲酰胺的同时测定

本文建立了液相色谱法同时测定鞋用发泡材料中甲酰胺和偶氮二甲酰胺的分析方法,优化了仪器分析条件。结果表明,方法线性范围为20~100μg/mL,方法检出限为0.24、0.40mg/kg,回收率为93.1%~95.7%,相对标准偏差4.8%~7.4%。市售55批次鞋用发泡材料样品中,共有1批次检出偶氮二甲酰胺(检出率1.8%)。使用傅里叶变换红外光谱仪鉴别了阳性样品材料种类为EVA,本方法重复性好,结果可靠,适用于鞋用发泡材料中甲酰胺和偶氮二甲酰胺的检测。

两性聚乙烯胺的制备与性能研究

本文通过选择N-乙烯基甲酰胺、丙烯酸为主要单体,采用自由基聚合制备聚(N-乙烯基甲酰胺-co-丙烯酸)共聚物,共聚物经碱水解后制备聚(乙烯胺-co-丙烯酸)。探讨了反应转化率和共聚产物的特性粘数的影响因素,包括共聚单体的浓度、引发剂浓度、反应温度及时间,摸索其最佳制备条件。此制备方法工艺简单,产物分子量及氨基含量可控。并考察聚合物在造纸湿部过程的表现,其在纸张增强、助留助滤、灰分保留、施胶性上均有明显的增效作用。

非醇盐法制备铝基气凝胶及其对阴离子染料的吸附性能研究

采用非醇盐法和常压干燥工艺,以硝酸铝为前驱体,制备了铝基气凝胶材料。考察了无水乙醇用量,甲酰胺用量,环氧丙烷用量对凝胶化时间的影响。采用傅立叶变换红外光谱仪(FTIR)、透射电子显微镜(SEM)和氮气吸附-脱附仪对铝碳基气凝胶的表观基团、形貌和结构等进行表征。此外,考察了铝基气凝胶对橙黄Ⅱ染料废水的吸附性能。结果表明,该类气凝胶具有低成本、易操作、吸附性能佳等优势,在工业污染废水处理等领域具有潜在的应用价值。

N-Arylation of azaheterocycles with aryl and heteroaryl halides catalyzed by iminodiacetic acid resin-chelated copper complex

Iminodiacetic acid resin-chelated copper(Ⅱ) complex is effective in cross-coupling reactions between azaheterocycles and aryl or heteroaryl halides,providing N-arylated products in good to excellent yields.The copper catalyst is air stable and can be readily recovered and reused with minimal loss of activity for three runs.

CuI/Proline-catalyzed N-Arylation of Nitrogen Heterocycles

Ma＇s CuI/proline procedure for the catalytic cross coupling between nitrogen heterocycles and aryl halides was markedly improved. The key finding was that K3PO4 was a much better base than K2CO3 for the reaction. With this new reaction condition the cross coupling with aryl iodides could be accomplished in 1,4-dioxane instead of DMSO. This reactin also could be carried out in DMF. Furthermore, the coupling yields under the new conditions are usually higher than in Ma＇s original methods.

A bifunctional and recyclable catalyst:Amine and ionic liquid grafting on MOFs for the one-pot synthesis of N-aryl oxazolidin-2-ones

A bifunctional heterogeneous catalyst was designed and synthesized,denoted DMEDA/IL–NH2-MIL-101.The structure and physical-chemical characterization of DMEDA/IL–NH2-MIL-101 and its precursors were characterized by SEM,N2 adsorption-desorption,XPS,FT-IR,PXRD,elemental analysis,and TGA techniques.The date showed that the two catalytic components of N,N-dimethylethylenediamine(DMEDA)and 1-butyl-3-methylimidazolium bromide(BmimBr)were chemically immobilized in NH2-MIL-101 nanocages.The amine of DMEDA was grafted onto carrier NH2-MIL-101 by N–Cr coordinate covalent bonds and the ionic liquid of BmimBr(IL(Br-))was anchored in the NH2-MIL-101 nanocages by'ship-in-a-bottle'method,in which the amidogen of NH2-MIL-101 condensed with N,N-carbonyldiimidazole(CDI)firstly,and then alkylated with 1-bromo butane.This novel heterogeneous catalyst with two different active sites can efficiently catalyze the synthesis of N-aryl oxazolidin-2-ones from carbon dioxide(CO2),epoxides,and anilines in one-pot under mild solvent-free conditions.It not only showed good stability and recoverability after five cycles but also exhibited shape selectivity for the substrate due to the synergic catalysis of amine,ionic liquid,and NH2-MIL-101.This novel bifunctional material is a promising solid catalyst for the green synthesis of N-aryl oxazolidin-2-ones.

One-step synthesis of carbon-supported copper nanoparticles from biomass for N-arylation of pyrazole

Carbon-supported copper catalyst was prepared for the first time in one-step with copper nitrate and corn stalk through calcination under different temperatures. Uniformly dispersed nanoparticles were obtained and were identified to be Cu（0） and Cu（Ⅰ） in XRD patterns. Excellent catalytic activity and selectivity were achieved in the N-arylation of pyrazole under ligand and protection gas free conditions. About90.4% of product yield was achieved with only 0.5 mol% of copper catalyst（Cu-C-300）, which was considerably more efficient than previous reports. XPS results suggested that the N-arylation of pyrazole activity was closely related to the surface Cu（Ⅰ） species.

超薄层羟镁铝石纳米片的制备和应用

羟镁铝石是水中有害阴离子组分的有效去除剂,且在处理过程中不引发二次污染,但难以经传统阴离子黏土合成技术制备。利用优化后机械化学方法合成了高纯羟镁铝石,并进一步通过片层剥离技术成功制备了超薄层羟镁铝石纳米片,避免了传统方法制备的羟镁铝石因颗粒团聚而吸附性能无法充分发挥的情况。文中尝试了6种分层剂(甲醇、乙醇、正丁醇、丙酮、天冬酰胺、甲酰胺),其中甲酰胺分层效果最佳,由其制备的超薄层羟镁铝石片层纤薄、孔隙发育,比表面积达163.3 m^(2)/g,对典型有害组分Cr(Ⅵ)、Sb(Ⅲ)、Sb(Ⅴ)的吸附容量则分别可达12.98、25.46、29.18 mg/L,显著高于未分层羟镁铝石及其他分层剂处理后的羟镁铝石。超薄层羟镁铝石纳米片在水污染处理领域有广阔应用前景。

Boosting the Ni-Zn interplay via O/N dual coordination for high-efficiency CO_(2) electroreduction

Design of supportive atomic sites with a controllably adjusted coordinating environment is essential to advancing the reduction of CO_(2) to value-added fuels and chemicals and to achieving carbon neutralization.Herein,atomic Ni(Zn)sites that are uniquely coordinated with ternary Zn(Ni)/N/O ligands were successfully decorated on formamide-derived porous carbon nanomaterials,possibly forming an atomic structure of Ni(N_(2)O_(1))-Zn(N_(2)O_(1)),as studied by combining X-ray photoelectron spectroscopy and X-ray absorption spectroscopy.With the mediation of additional O coordination,the Ni-Zn dual site induces significantly decreased desorption of molecular CO.The NiZn-NC decorated with rich Ni(N_(2)O_(1))-Zn(N_(2)O_(1))sites remarkably gained>97%CO Faraday efficiency over a wide potential range of -0.8 to -1.1 V(relative to reversible hydrogen electrode).Density functional theory computations suggest that the N/O dual coordination effectively modulates the electronic structure of the Ni-Zn duplex and optimizes the adsorption and conversion properties of CO_(2) and subsequent intermediates.Different from the conventional pathway of using Ni as the active site in the Ni-Zn duplex,it is found that the Ni-neighboring Zn sites in the Ni(N_(2)O_(1))-Zn(N_(2)O_(1))coordination showed much lower energy barriers of the CO_(2) protonation step and the subsequent dehydroxylation step.

关于瑜伽垫中甲酰胺释放量及释放速率的检测方法

本文研究并建立了利用热脱附—气相色谱质谱联用仪(GC-MS)检测瑜伽垫中甲酰胺释放量的方法,同时还建立了检测甲酰胺释放速率的方法。本文所公开的具体方法是,在室温条件下,将待检测样品置于环境气候舱中,模拟室内环境,在空气温度为23.0℃±1.0℃、空气相对湿度为50.0%±5.0%、空气交换率为1.0-1次/小时、空气流速为0.1~0.3 m/s的实验条件下进行释放,抽气泵以1.0 L/min的流量抽气4~6 min,以便于置换采样系统的空气;以0.5 mL/min的流速采集气体样品20 min至吸附管内,完成后用热脱附气相色谱质谱联用仪分析挥发性有机物。