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Thermodynamic Study and Spectroscopic Analysis of a Charge-Transfer Complex between 3,5-Diamino-1,2,4-Triazole and 6-Methyl-1,3,5-Triazine-2,4-Diamine with Chloranilic Acid 3,5-二氨基-1,2,4-三唑与6-甲基-1,3,5-三嗪-2,4-二氨基与氯苯胺酸电荷转移配合物的热力学研究和光谱分析
Pub Date : 2020-02-13 DOI: 10.4236/ojpc.2020.101002
K. Al-Ahmary, Ashwaq Alharbi
Studying of charge-transfer (CT) and proton transfer interactions is essential due to their important role in many biological field and industrial applications. The current work will add more information’s about the nature of interaction between 3,5-diamino-1,2,4-triazole (DAT) and 6-methyl-1,3,5-triazine-2,4-diamine (MTDA) with 3,6-dichloro-2,5-dihydroxy-p-benzoquinone (chloranilic acid CLA) which was studied spectrophotometrically in Ethanol (EtOH) and Methanol (MeOH) solvents at different temperatures. The molecular composition of the formed complexes was studied by applying continuous variation and spectrophotometric titration methods and found to be 1:1 charge transfer complex for both Complex (DAT:CLA) and (MTDA:CLA) which are produced. Minimum-Maximum absorbance’s method has been applied to calculate the formation constant KCT and molecular extinction coefficient (e); they recorded high values confirming high stability of the produced complexes. Oscillator strength (f), transition dipole moment (μ), ionization potential (IP) and dissociation energy (W) of the formed CT-complexes were also determined and evaluated; they showed solvent dependency. It is concluded that the formation constant (KCT) of the complexes is found to depend on the nature of both electron acceptor and donors and on the polarity of solvents.
电荷转移(CT)和质子转移相互作用的研究是必不可少的,因为它们在许多生物领域和工业应用中发挥着重要作用。目前的工作将增加更多关于3,5-二氨基-1,2,4-三唑(DAT)和6-甲基-1,3,5-三嗪-2,4-二胺(MTDA)与3,6-二氯-2,5-二羟基对苯醌(氯苯胺酸CLA)之间相互作用性质的信息,该相互作用是在乙醇(EtOH)和甲醇(MeOH)溶剂中在不同温度下用分光光度法研究的。用连续变化法和分光光度滴定法研究了所形成的配合物的分子组成,发现所产生的配合物(DAT:CLA)和(MTDA:CLA)都是1:1的电荷转移配合物。应用最小-最大吸光度法计算了形成常数KCT和分子消光系数(e);它们记录了高值,证实了所产生的复合物的高稳定性。测定并评价了所形成的CT配合物的振子强度(f)、跃迁偶极矩(μ)、电离势(IP)和离解能(W);它们表现出溶剂依赖性。结果表明,配合物的形成常数(KCT)取决于电子受体和给体的性质以及溶剂的极性。
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引用次数: 1
Taking into Account Density Fluctuations in a Solvent in a Model of Dissolution 在溶解模型中考虑溶剂的密度波动
Pub Date : 2019-10-31 DOI: 10.4236/ojpc.2019.94012
I. A. Ar'ev
Earlier it was shown by different authors that there are cavities (vacancies, holes) in any liquid. The cavities should play a prominent role in dissolution processes. Nevertheless this fact was ignored in previous model of dissolution. The sizes of the cavities in different solvents containing benzene molecules were determined using solvent induced spectral shift method. The measurements of S1←S0 benzene transition spectral shifts permit to conclude that 1) macroscopic excess volumes play an almost negligible role in processes of benzene dissolution in very different solvents and 2) the minimal size of the cavity in water able to accommodate benzene molecule coincides with the solute size. Generalization of this conclusion to other nonpolar aromatics leads to evaluation contraction of the solutes under aqueous solvent influence permits to predict the solubility values of other aromatics in water and to evaluate effect of enhancement hydrate cell around these molecules on solubility.
早些时候,不同的作者表明,任何液体都有空腔(空位,洞)。这些空腔在溶解过程中起着重要的作用。然而,这一事实在以前的解散模型中被忽略了。采用溶剂诱导光谱移法测定了不同含苯溶剂中空腔的大小。通过对S1←50苯跃迁光谱位移的测量可以得出以下结论:1)宏观过量体积在苯在不同溶剂中的溶解过程中所起的作用几乎可以忽略不计;2)水中能够容纳苯分子的最小空腔尺寸与溶质尺寸一致。将这一结论推广到其他非极性芳烃,可以评估溶质在水溶液影响下的收缩,从而预测其他芳烃在水中的溶解度值,并评估这些分子周围的增强水合物细胞对溶解度的影响。
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引用次数: 0
Electrochemical Study of the Synergistic Effect of Two Copper Corrosion Inhibitors, Nicotinic Acid (NAC) and Nicotinamide (NAM) in Two Different Media 两种铜缓蚀剂烟酸(NAC)和烟酰胺(NAM)在两种不同介质中协同作用的电化学研究
Pub Date : 2019-10-31 DOI: 10.4236/ojpc.2019.94011
Y. S. Brou, N. H. Coulibaly, N. Y. S. Diki, J. Creus, A. Trokourey
Inhibitive properties of NAC and NAM as well as their mixture have been investigated in two different corrosive media through potentiodynamic polarization and electrochemical impedance spectroscopy at 298 K. These electrochemical measurements indicate that the inhibition efficiency increases with the concentration for each of the inhibitors used separately as well as for their mixture. In both cases, the combination behaves as mixed type inhibitor with a great cathodic tendency. NaCl 3.5% highlights an antagonist effect of NAM which reduces the effectiveness of NAC whereas HNO3 1M shows a synergistic effect between them.
通过298K下的动电位极化和电化学阻抗谱,研究了NAC和NAM及其混合物在两种不同腐蚀介质中的缓蚀性能。这些电化学测量表明,单独使用的每种抑制剂及其混合物的缓蚀效率都随着浓度的增加而增加。在这两种情况下,该组合表现为混合型抑制剂,具有很大的阴极倾向。3.5%的NaCl突出了NAM的拮抗作用,其降低了NAC的有效性,而HNO3 1M显示了它们之间的协同作用。
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引用次数: 1
Dipole Moments of the Bioactive Constituents Present in Flutab Drug by Ab-Initio Calculations 应用Ab Initio计算Flutab药物中生物活性成分的偶极矩
Pub Date : 2019-10-31 DOI: 10.4236/ojpc.2019.94013
Raghad Alajlani, Amal Alssadi
Many of the technology and computational chemistry applications are used to study drugs and their biological effects. Flutab® drug contains Paracetamol, Diphenhydramine and Pseudoephedrine. Ab-initio calculations were performed at DFT/B3LYP and HF methods with three basis sets, namely, STO-3G, 3-21G, and 6-31G(d) in order to calculate the dipole moments of the three constituents of Flutab® drug. The Diphenhydramine compound was found to be the most stable constituent, with the lowest value of dipole moment.
许多技术和计算化学应用都用于研究药物及其生物效应。Flutab®药物含有对乙酰氨基酚、苯海拉明和伪麻黄碱。采用DFT/B3LYP和HF方法,用STO-3G、3-21G和6-31G(d)三个基组进行从头计算,以计算Flutab®药物三种成分的偶极矩。发现苯海拉明化合物是最稳定的成分,偶极矩值最低。
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引用次数: 0
One-Electron-Addition to Pentavalent Phosphorus with the Phosphorus-Chlorine Bond as Acceptor Introducing a Fundamental Distinction in Substitution Mechanism between SN2(P) and SN2(C) 以磷-氯键为受体的五价磷的单电子加成引入了SN2(P)和SN2(C)取代机理的基本区别
Pub Date : 2019-07-22 DOI: 10.4236/ojpc.2019.93010
H. Buck
An electron-addition, under single-crystal conditions, to pentavalent phosphorus compounds as Cl-P (=O, S) Y, Z with the P-Cl bond as electron-accepting group, is selected as an additional model for SN2(P) like reactions. It is demonstrated that the geometric information stored in the tetrahedral configuration (substrate) can be transmitted in the corresponding trigonal bipyramidal (TBP) state for nucleophilic substitution. In this article, we focus on these specific mechanistic aspects of carbon and phosphorus. We consider our study as a contribution to the significance of these (bio)chemical intermediates.
在单晶条件下,五价磷化合物以Cl-P (=O, S) Y, Z的电子加成,以P- cl键为电子接受基团,被选择作为SN2(P)类反应的附加模型。结果表明,存储在四面体结构(底物)中的几何信息可以在相应的三角双锥体(TBP)状态下进行亲核取代。在这篇文章中,我们集中在这些具体的机制方面的碳和磷。我们认为我们的研究是对这些(生物)化学中间体的意义的贡献。
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引用次数: 0
Clusters: Viscosity Cause? 聚簇:粘滞原因?
Pub Date : 2019-07-22 DOI: 10.4236/OJPC.2019.93007
V. P. Malyshev, A. Makasheva
The significance of the work is determined by the need to develop a cluster theory of the liquid state of a substance in order to more deeply substantiate the viscosity, which is still expressed by empirical parameters within the framework of ideal ideas about the stratified flow of a liquid. According to the reference data on the dynamic viscosity of the melts for chlorides of the first group of the Periodic System, the approximating dependences in the form of cluster-associate and Frenkel’s models were constructed at various temperatures. The first model is based on taking into account the share of particles that cannot overcome the thermal melting barrier and thus serve to form virtual clusters and associates while preserving the structural motifs of the solid phase. In the framework of the cluster-associate viscosity model developed by the authors, these formations determine the melt viscosity and serve as flow units to which the energy of fluid motion is applied. The Frenkel’s model allows us to estimate the activation energy of fluidity. Calculations show that by comparing this energy with the degree of cluster association obtained in the framework of the cluster-associate model, a fairly close linear correlation is obtained, and the proportionality coefficient has the meaning of the activation energy per cluster. This energy does not go beyond the van der Waals energy of the unsaturated intermolecular bond characteristic of the interaction of particles in a liquid. This confirms the earlier established by the authors a similar pattern for melts of simple substances, based on the understanding of fluidity as a consequence of the destruction of cluster associates while preserving the clusters themselves.
这项工作的意义在于需要发展一种物质液态的聚类理论,以便更深入地证实粘度,而粘度仍然是在关于液体分层流动的理想思想框架内由经验参数表示的。根据周期系统第一族氯化物熔体动态黏度的参考数据,建立了不同温度下的团簇-缔合和Frenkel模型的近似依赖关系。第一个模型是基于考虑到不能克服热熔障碍的粒子的份额,从而在保留固相结构基序的同时形成虚拟团簇和关联。在作者开发的团簇-关联粘度模型框架中,这些地层决定熔体粘度,并作为流体运动能量应用的流动单元。Frenkel模型使我们能够估计流体的活化能。计算表明,将该能量与聚类-关联模型框架下得到的聚类关联度进行比较,得到了相当密切的线性相关关系,比例系数具有每簇活化能的含义。这个能量不超过液体中粒子相互作用的不饱和分子间键的范德华能。这证实了作者早先建立的简单物质熔体的类似模式,这是基于对流动性的理解,这是由于团簇伴合体的破坏而保留团簇本身的结果。
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引用次数: 0
Thermochemical Characterization of Casamance Biomass Residues for Production of Combustibles Briquettes 燃烧型煤生产用卡萨芒斯生物质残渣的热化学表征
Pub Date : 2019-07-22 DOI: 10.4236/OJPC.2019.93009
Mamadou Bâ, L. Ndiaye, I. Youm
The development of alternatives energies illustrates the common interest of all countries in reducing greenhouse gas emissions and combating climate change. Thermochemical treatment of municipal solid waste, agricultural and forestry wastes is a major challenge for this XXIst century to replace petroleum fuels. Thermogravimetric analysis (TGA) makes it possible to elucidate the thermal behavior of Casamance (Senegal) biomass residues, mass losses and decomposition rate, under inert (N2) atmosphere and oxidizing (O2) atmosphere. Carbonization and briquetting techniques of these various residues encountered in this part of Senegal country, by densification in order to produce fuel briquettes (call biochars) will be used to improve stoves for cooking. Samples used in this study are peanuts shells (PNS), cashew nut shells (CNS), palm nut shells (PLS) and millet stems (MS). Elemental and approximate analyses make it possible to determine the CHNSO* composition, volatile matter, fixed carbon and ashes content of the samples used. Higher heating values (HHV) of the former residues are ranging from 28.60 MJ·kg-1, 26.51 MJ·kg-1, 29.69 MJ·kg-1 and 24.93 MJ·kg-1 respectively. The chars are obtained by slow pyrolysis with a heating rate of 5°C·min-1 from ambient temperature up to 800°C under inert atmosphere. The morphology of the samples is different for the four biomasses studied, from biomass in the form of wood fibers to a more compact biomass. The parietal composition of different samples presented was determined by Van Soest method using neutral detergents (NDS), acid detergent (ADS) and sulfuric acid (H2SO4, 72%); to solubilize successively extractable, hemicellulose and cellulose respectively; lignin was obtained by balance (Table 2). The samples show a high level of cellulose, this pseudo-component is very rich in carbon directly linked to the calorific value, whose values vary from 32.35%; 24.20%; 34.94% and 39.67% for PNS, PLS, CNS and MS respectively.
替代能源的发展表明了各国在减少温室气体排放和应对气候变化方面的共同利益。城市固体废物、农业和林业废物的热化学处理是21世纪取代石油燃料的一大挑战。热重分析(TGA)可以阐明卡萨芒斯(塞内加尔)生物质残留物在惰性(N2)和氧化性(O2)气氛下的热行为、质量损失和分解速率。塞内加尔这一地区遇到的各种残留物的碳化和压块技术,通过致密化生产燃料压块(称为生物炭),将用于改进烹饪炉。本研究中使用的样品为花生壳(PNS)、腰果壳(CNS)、棕榈果壳(PLS)和小米茎(MS)。元素分析和近似分析可以确定所用样品的CHNSO*成分、挥发性物质、固定碳和灰烬含量。前者的高热值(HHV)分别为28.60MJ·kg-1、26.51MJ·kg-1和29.69MJ·kg-1。煤焦是在惰性气氛下,从环境温度高达800°C,以5°C·min-1的加热速率缓慢热解得到的。所研究的四种生物质的样品形态不同,从木纤维形式的生物质到更紧凑的生物质。采用Van Soest法,使用中性洗涤剂(NDS)、酸性洗涤剂(ADS)和硫酸(H2SO4,72%)测定不同样品的壁成分;依次溶解可提取的半纤维素和纤维素;通过平衡获得木质素(表2)。样品显示出高水平的纤维素,这种伪成分富含与热值直接相关的碳,其值从32.35%不等;24.20%;PNS、PLS、CNS和MS分别为34.94%和39.67%。
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引用次数: 1
A Graph Theoretical Interpretation of Different Types of Energies of Elementary Particles, Atoms and Molecules 基本粒子、原子和分子不同类型能量的图理论解释
Pub Date : 2019-05-21 DOI: 10.4236/OJPC.2019.92003
J. Gálvez
The present work illustrates a predictive method, based on graph theory, for different types of energy of subatomic particles, atoms and molecules, to be specific, the mass defect of the first thirteen elements of the periodic table, the rotational and vibrational energies of simple molecules (such as , H2, FH and CO) as well as the electronic energy of both atoms and molecules (conjugated alkenes). It is shown that such a diverse group of energies can be expressed as a function of few simple graph-theoretical descriptors, resulting from assigning graphs to every wave function. Since these descriptors are closely related to the topology of the graph, it makes sense to wonder about the meaning of such relation between energy and topology and suggests points of view helping to formulate novel hypotheses about this relation.
目前的工作说明了一种基于图论的预测方法,用于亚原子粒子、原子和分子的不同类型的能量,具体来说,是元素周期表前十三元素的质量缺陷,简单分子(如H2、FH和CO)的旋转能和振动能以及原子和分子(共轭烯烃)的电子能。结果表明,这样一组不同的能量可以表示为几个简单的图论描述符的函数,这是将图分配给每个波函数的结果。由于这些描述符与图的拓扑结构密切相关,因此想知道能量和拓扑结构之间这种关系的含义是有意义的,并提出了有助于形成关于这种关系的新假设的观点。
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引用次数: 0
Basic Steps in Chemical Dissociation of Gaseous Molecules Using an Even-Odd Rule, a Specifically Adapted Periodic Table and a Covalent Bonding Rule 气体分子化学解离的基本步骤,使用奇偶规则,特别适应的元素周期表和共价键规则
Pub Date : 2019-05-21 DOI: 10.4236/OJPC.2019.92006
G. Auvert
When writing equations of chemical dissociation, students and scholars are taught two fundamental rules to balance the equation. On both sides of the equation, the types of elements and their quantity are conserved, as well as the global electrical charge. This paper introduces additional methods during dissociation of gaseous compounds, to precisely describe how electrical charges locally move and how bonding structures are modified. Specific rules revolving around electrons pairs displacements are developed and applied to about 150 dissociations of small gaseous molecules using atoms from the three first rows of the periodic table. Results obtained tend to demonstrate the relevance of these tools for chemists.
在编写化学离解方程时,学生和学者被教导平衡方程的两条基本规则。在方程的两侧,元素的类型及其数量是守恒的,全局电荷也是守恒的。本文介绍了气体化合物离解过程中的其他方法,以精确描述电荷如何局部移动以及键合结构如何改变。围绕电子对位移的特定规则被开发出来,并应用于使用周期表前三行原子的大约150个小气体分子的离解。所获得的结果往往证明了这些工具对化学家的相关性。
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引用次数: 1
The Interaction(s) between Calf-Skin Hyaluronic Acid (Hyaluronan) and Dermal Type I Calf-Skin Collagen under 254 nm UV Radiation: Ability of Hyaluronan to Alter Qualitative and Quantitative Dimerization of Collagen Tyrosine Residues 254 nm紫外线辐射下小牛皮肤透明质酸(玻尿酸)与真皮I型小牛皮肤胶原蛋白的相互作用:玻尿酸改变胶原蛋白酪氨酸残基定性和定量二聚化的能力
Pub Date : 2019-05-21 DOI: 10.4236/OJPC.2019.92004
J. Menter, Latoya Freeman, Ortega Edukye
The extracellular matrix (ECM) is the non-cellular component present within all tissues and organs, providing not only essential physical scaffolding for the cellular constituents and initiating crucial biochemical and biomechanical cues, required for tissue morphogenesis, differentiation and homeostasis. Roughly divided into two groups, these are 1) the main fibrous ECM proteins: collagens, elastins, fibronectins and laminins. 2) Classification of proteoglycans (PGs) is based on their location and binding. Although many different molecular interactions are possible, they depend on the cells’ condition (i.e. “Normal”, Aged, Wounded/Fibrotic, and cancerous). There is little or no data that addresses the influence of the surrounding ECM on dityrosine formation. As a simpler model, we have replaced total PG with hyaluronan (HA) and have used purified calf-skin collagen tyrosine, which forms dityrosine (A2) under 254 nm UV in buffered solution and (near) physiological temperatures. Our results reveal a complicated temperature dependence involving factors relating to collagen HA structure, and collagen’s photochemical activation parameters.
细胞外基质(ECM)是存在于所有组织和器官中的非细胞成分,不仅为细胞成分提供必要的物理支架,还启动组织形态发生、分化和稳态所需的关键生化和生物力学线索。大致分为两组,1)主要的纤维性ECM蛋白:胶原蛋白、弹性蛋白、纤维连接蛋白和层粘连蛋白。2)蛋白聚糖(pg)的分类是基于它们的定位和结合。尽管可能有许多不同的分子相互作用,但它们取决于细胞的状况(即“正常”、衰老、受伤/纤维化和癌变)。很少或没有数据表明周围的ECM对二酪氨酸形成的影响。作为一个更简单的模型,我们用透明质酸(HA)代替了总PG,并使用了纯化的小牛皮肤胶原酪氨酸,它在缓冲溶液和(接近)生理温度的254 nm紫外线下形成二酪氨酸(A2)。我们的研究结果揭示了一个复杂的温度依赖关系,涉及胶原蛋白HA结构和胶原蛋白的光化学激活参数。
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引用次数: 0
期刊
物理化学期刊(英文)
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