Solar interfacial water evaporation to obtain pure water has attracted extensive attention in recent years. In this work, based on the excellent optical property of FeS2 and the cross-linking nanostructure of chitosan (CTS), a FeS2@CTS hydrogel composite film for solar interfacial water evaporation was developed by hydrothermal synthesis and the following composite coating technology. The prepared FeS2@CTS presented high solar absorptivity of 95.27% and fast optical response capability. Under the optimized condition, the evaporation rate of pure water reached 3.34 kg m−2 h−1 and the photothermal conversion efficiency was 103.06% under one sun irradiation. In five runs, the evaporation rate of the FeS2@CTS was stable, indicating the excellent cycle stability. Also, in the desalination test, the stable evaporation rate of 1.74 kg m−2 h−1 was obtained in five runs. Due to the simple preparation method, low cost, and outstanding interfacial evaporation property, this FeS2@CTS indicates great potential for the seawater desalination or other photothermal conversion applications.
近年来，利用太阳界面蒸发获得纯水的研究受到了广泛的关注。本文基于FeS2优异的光学性能和壳聚糖(CTS)的交联纳米结构，采用水热合成和复合涂层技术制备了一种用于太阳界面水蒸发的FeS2@CTS水凝胶复合膜。制备的FeS2@CTS具有95.27%的太阳吸收率和快速的光响应能力。在优化条件下，单次照射下，纯水蒸发速率可达3.34 kg m−2 h−1，光热转换效率为103.06%。在5次运行中，FeS2@CTS的蒸发速率稳定，表明循环稳定性好。在脱盐试验中，5次运行获得了1.74 kg m−2 h−1的稳定蒸发速率。由于制备方法简单，成本低，界面蒸发性能优异，该FeS2@CTS在海水淡化或其他光热转换应用中具有很大的潜力。
{"title":"A flexible, high-efficiency, and low-cost FeS2@CTS hydrogel film for solar interface water evaporation","authors":"Yunsong Xu, Yanran Gu, Zhongping Yao, Songtao Lu, Xiaohong Wu, Zhaohua Jiang","doi":"10.1139/cjc-2022-0174","DOIUrl":"https://doi.org/10.1139/cjc-2022-0174","url":null,"abstract":"Solar interfacial water evaporation to obtain pure water has attracted extensive attention in recent years. In this work, based on the excellent optical property of FeS2 and the cross-linking nanostructure of chitosan (CTS), a FeS2@CTS hydrogel composite film for solar interfacial water evaporation was developed by hydrothermal synthesis and the following composite coating technology. The prepared FeS2@CTS presented high solar absorptivity of 95.27% and fast optical response capability. Under the optimized condition, the evaporation rate of pure water reached 3.34 kg m−2 h−1 and the photothermal conversion efficiency was 103.06% under one sun irradiation. In five runs, the evaporation rate of the FeS2@CTS was stable, indicating the excellent cycle stability. Also, in the desalination test, the stable evaporation rate of 1.74 kg m−2 h−1 was obtained in five runs. Due to the simple preparation method, low cost, and outstanding interfacial evaporation property, this FeS2@CTS indicates great potential for the seawater desalination or other photothermal conversion applications.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"28 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81422696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kailey Browne, Y. Pei, I. Singh, S. J. Payne, Zhe She
Phosphorous is an important environmental health parameter as the availability of phosphorus within water systems plays an essential role in the prevalence of harmful algal blooms (cyanobacteria blooms). Currently, phosphates are detected using sensitive chromatographic and colorimetric techniques; however, major disadvantages stem from the lack of anion selectivity in samples with complex matrices, as well as the high cost of analysis. Electrochemical techniques utilizing self-assembled monolayers can provide a cheaper yet sensitive method of detection. This work explores the modification of a gold working electrode using pyridine-zinc (II) complexes. The implementation of self-assembled monolayers allows for an ultrasensitive and selective method of indirect detection of the H2PO4- species, ranging in concentrations between 0.0 and 1.2. fM phosphate. Electrochemical techniques such as cyclic voltammetry (CV) and square-wave voltammetry (SWV) were explored for their phosphate detection abilities, with detection limits of 4.0 x 10-16 and 9.0 x 10-17 M H2PO4-, respectively. X-ray photoelectron spectroscopy (XPS) measurements were also taken to confirm the modification of the electrode. The selectivity of this sensor towards phosphate anions was successfully explored for this sensor in the presence of potential interfering agents (sulfate, chlorine, carbonate, fluoride, nitrite and hypochlorite ions), and applicability of sensor was also explored through the detection of phosphate in a tap and lake water sample.
磷是一个重要的环境健康参数，因为水系统中磷的可用性在有害藻华(蓝藻华)的流行中起着至关重要的作用。目前，磷酸盐的检测使用灵敏的色谱和比色技术;然而，主要的缺点是在具有复杂基质的样品中缺乏阴离子选择性，以及分析成本高。利用自组装单层的电化学技术可以提供一种既便宜又灵敏的检测方法。本研究探讨了用吡啶-锌(II)配合物修饰金工作电极。自组装单层的实现允许超灵敏和选择性的方法间接检测H2PO4-物种，浓度范围在0.0和1.2之间。调频磷酸。研究了循环伏安法(CV)和方波伏安法(SWV)等电化学技术对磷酸盐的检测能力，检测限分别为4.0 × 10-16和9.0 × 10-17 M H2PO4-。x射线光电子能谱(XPS)测量也证实了电极的修饰。在潜在干扰剂(硫酸盐、氯离子、碳酸盐离子、氟化物离子、亚硝酸盐离子和次氯酸盐离子)存在的情况下，成功探索了该传感器对磷酸阴离子的选择性，并通过检测自来水和湖水样品中的磷酸盐，探索了该传感器的适用性。
{"title":"Ultrasensitive Electrochemical Phosphate Detection by Pyridine-zinc(II) Complex","authors":"Kailey Browne, Y. Pei, I. Singh, S. J. Payne, Zhe She","doi":"10.1139/cjc-2022-0212","DOIUrl":"https://doi.org/10.1139/cjc-2022-0212","url":null,"abstract":"Phosphorous is an important environmental health parameter as the availability of phosphorus within water systems plays an essential role in the prevalence of harmful algal blooms (cyanobacteria blooms). Currently, phosphates are detected using sensitive chromatographic and colorimetric techniques; however, major disadvantages stem from the lack of anion selectivity in samples with complex matrices, as well as the high cost of analysis. Electrochemical techniques utilizing self-assembled monolayers can provide a cheaper yet sensitive method of detection. This work explores the modification of a gold working electrode using pyridine-zinc (II) complexes. The implementation of self-assembled monolayers allows for an ultrasensitive and selective method of indirect detection of the H2PO4- species, ranging in concentrations between 0.0 and 1.2. fM phosphate. Electrochemical techniques such as cyclic voltammetry (CV) and square-wave voltammetry (SWV) were explored for their phosphate detection abilities, with detection limits of 4.0 x 10-16 and 9.0 x 10-17 M H2PO4-, respectively. X-ray photoelectron spectroscopy (XPS) measurements were also taken to confirm the modification of the electrode. The selectivity of this sensor towards phosphate anions was successfully explored for this sensor in the presence of potential interfering agents (sulfate, chlorine, carbonate, fluoride, nitrite and hypochlorite ions), and applicability of sensor was also explored through the detection of phosphate in a tap and lake water sample.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"143 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74951423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present an implementation of the multiconfiguration time-dependent Hartree–Fock method based on the adaptive finite element method for molecules under intense laser pulses. For efficient simulations, orbital functions are propagated by a stable propagator using the short iterative Arnoldi scheme and our implementation is parallelized for distributed memory computing. This is demonstrated by simulating high-harmonic generation from a water molecule and achieves a simulation of multielectron dynamics with overwhelmingly less computational time, compared to our previous work [Sawada, R. et al. Phys. Rev. A, 2016, 93, 023434].
提出了一种基于自适应有限元法的多组态时变Hartree-Fock方法。为了提高模拟效率，轨道函数采用短迭代Arnoldi格式的稳定传播器进行传播，并对分布式内存计算进行并行化实现。这是通过模拟水分子的高谐波产生来证明的，与我们以前的工作相比，用更少的计算时间实现了多电子动力学的模拟[Sawada, R. et al.]。理论物理。[j].中国机械工程，2016,33(3):433 - 434。
{"title":"Efficient simulation of multielectron dynamics in molecules under intense laser pulses: implementation of the multiconfiguration time-dependent Hartree–Fock method based on the adaptive finite element method","authors":"Y. Orimo, Takeshi Sato, K. Ishikawa","doi":"10.1139/cjc-2022-0280","DOIUrl":"https://doi.org/10.1139/cjc-2022-0280","url":null,"abstract":"We present an implementation of the multiconfiguration time-dependent Hartree–Fock method based on the adaptive finite element method for molecules under intense laser pulses. For efficient simulations, orbital functions are propagated by a stable propagator using the short iterative Arnoldi scheme and our implementation is parallelized for distributed memory computing. This is demonstrated by simulating high-harmonic generation from a water molecule and achieves a simulation of multielectron dynamics with overwhelmingly less computational time, compared to our previous work [Sawada, R. et al. Phys. Rev. A, 2016, 93, 023434].","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"3 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88712124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The solubility and thermodynamics of solvation due to solute-solvent interactions of glycine, DL-alanine, DL-serine and DL-valine were determined in this study. Mainly the transfer of Gibbs frees energies from aqueous to aqueous sodium and potassium iodide salt solutions were considered which were calculated by direct experimental solubility data and via theoretical calculations. The equilibrium solubilities were measured at 298.15K using simple ‘formol titration’. Various important physicochemical factors like enthalpy of solvation, molar volume, molar mass, molar density, etc. in aqueous electrolyte solutions were calculated at standard temperature. The thermodynamic parameters were explained to conclude about the virtual stability of the zwitterionic solutes in aqueous salt mixtures. The factors which are associated with solubility were also explained and correlated with physical and thermodynamic point of view.
{"title":"Solvation Thermodynamics of Four Amino Acids in Electrolytic Solutions of Sodium and Potassium Iodide salts at 298.15 K","authors":"S. Kundu, K. Mahali, Sanjay Dhar Roy","doi":"10.1139/cjc-2022-0251","DOIUrl":"https://doi.org/10.1139/cjc-2022-0251","url":null,"abstract":"The solubility and thermodynamics of solvation due to solute-solvent interactions of glycine, DL-alanine, DL-serine and DL-valine were determined in this study. Mainly the transfer of Gibbs frees energies from aqueous to aqueous sodium and potassium iodide salt solutions were considered which were calculated by direct experimental solubility data and via theoretical calculations. The equilibrium solubilities were measured at 298.15K using simple ‘formol titration’. Various important physicochemical factors like enthalpy of solvation, molar volume, molar mass, molar density, etc. in aqueous electrolyte solutions were calculated at standard temperature. The thermodynamic parameters were explained to conclude about the virtual stability of the zwitterionic solutes in aqueous salt mixtures. The factors which are associated with solubility were also explained and correlated with physical and thermodynamic point of view.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"14 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75669180","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Huynh Nguyen Anh Tuan, Le Minh Tam, Giang Tien Nguyen
Here, a 1-octadecanol/methylated mesoporous silica (OD/M-MS) shape-stabilized phase change material (SSPCM) was prepared with enhanced thermal energy storage. The M-MS was synthesized by methylation of low-cost mesoporous silica (MS) with trimethylchlorosilane. Fourier-transformed infrared spectroscopy (FTIR), N2 adsorption-desorption isotherm, and thermogravimetric analysis (TGA) confirmed successful methylation of MS. 1-Octadecanol (OD) was then impregnated into the pores of MS and M-MS to form OD/MS and OD/M-MS SSPCMs and their thermal properties were thoroughly characterized and compared. FTIR result of OD/MS revealed interfacial hydrogen bond (H-bond) interactions between the hydroxyl group (–OH) on the OD molecules and silanol groups (Si–OH) on the MS surface. These interactions prevented the free movement and ordered arrangement of OD molecules for crystallization, thus declining the heat storage capacity. By methylating the MS surface, the H-bond interactions were suppressed and the OD/M-MS could recover the thermal performance. The heat storage capacity increased by 96.8% from 43.5 J/g of OD/MS to 85.6 J/g of OD/M-MS. Moreover, a test of 400 accelerated thermal cycles proved good thermal reliability for OD/M-MS SSPCM. This work provides an effective strategy to achieve OD/M-MS SSPCM with low cost and high thermal performance, promising for large-scale thermal energy storage applications.
{"title":"Methylated Mesoporous Silica Loaded with 1-Octadecanol as a New Shape-Stabilized Phase Change Material for Enhanced Thermal Energy Storage Efficiency","authors":"Huynh Nguyen Anh Tuan, Le Minh Tam, Giang Tien Nguyen","doi":"10.1139/cjc-2022-0281","DOIUrl":"https://doi.org/10.1139/cjc-2022-0281","url":null,"abstract":"Here, a 1-octadecanol/methylated mesoporous silica (OD/M-MS) shape-stabilized phase change material (SSPCM) was prepared with enhanced thermal energy storage. The M-MS was synthesized by methylation of low-cost mesoporous silica (MS) with trimethylchlorosilane. Fourier-transformed infrared spectroscopy (FTIR), N2 adsorption-desorption isotherm, and thermogravimetric analysis (TGA) confirmed successful methylation of MS. 1-Octadecanol (OD) was then impregnated into the pores of MS and M-MS to form OD/MS and OD/M-MS SSPCMs and their thermal properties were thoroughly characterized and compared. FTIR result of OD/MS revealed interfacial hydrogen bond (H-bond) interactions between the hydroxyl group (–OH) on the OD molecules and silanol groups (Si–OH) on the MS surface. These interactions prevented the free movement and ordered arrangement of OD molecules for crystallization, thus declining the heat storage capacity. By methylating the MS surface, the H-bond interactions were suppressed and the OD/M-MS could recover the thermal performance. The heat storage capacity increased by 96.8% from 43.5 J/g of OD/MS to 85.6 J/g of OD/M-MS. Moreover, a test of 400 accelerated thermal cycles proved good thermal reliability for OD/M-MS SSPCM. This work provides an effective strategy to achieve OD/M-MS SSPCM with low cost and high thermal performance, promising for large-scale thermal energy storage applications.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"176 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82803450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A combination of ion mobility mass spectrometry (IMS-MS), collision-induced dissociation (CID), RRKM modeling, and computational chemistry was used to determine the structure and unimolecular chemistry of dimeric and trimeric sulfonated meso-tetraphenylporphyrins with negative charges from -2 to -5. By comparing experimental collision cross-sections obtained from calibrated IMS drift times with calculated cross sections for the lowest energy calculated structures, it was confirmed that dimer species have a bridged structure where the two monomers are connected through iron-sulfonic interactions. Dimer species with the charge states -4 and -5 dissociate into two monomer units where the charge is distributed between the monomers. Dimers with lower charge states also lose neutral SO2 and SO3 groups. For trimeric species with charge states of -3 and -4, IMS identifies three and two isomers, respectively. It was confirmed that the -4 charged trimer isomers consist of one with three stacked monomers and one in which the third monomer unit is connected to a stacked dimer via two iron-sulfonic bonds (bridged/stacked). Both yielded the same CID breakdown diagram confirming that the two isomers likely interconvert prior to dissociation. The significantly larger density of states of the bridged-stacked structure compared to the stacked structure means the former is likely the reactive configuration.
{"title":"Structures and Dissociation of Iron Porphyrin Complexes by Ion Mobility and Collision-Induced Dissociation Mass Spectrometry","authors":"Ameneh Gholami, O. Hampe, P. Mayer","doi":"10.1139/cjc-2022-0133","DOIUrl":"https://doi.org/10.1139/cjc-2022-0133","url":null,"abstract":"A combination of ion mobility mass spectrometry (IMS-MS), collision-induced dissociation (CID), RRKM modeling, and computational chemistry was used to determine the structure and unimolecular chemistry of dimeric and trimeric sulfonated meso-tetraphenylporphyrins with negative charges from -2 to -5. By comparing experimental collision cross-sections obtained from calibrated IMS drift times with calculated cross sections for the lowest energy calculated structures, it was confirmed that dimer species have a bridged structure where the two monomers are connected through iron-sulfonic interactions. Dimer species with the charge states -4 and -5 dissociate into two monomer units where the charge is distributed between the monomers. Dimers with lower charge states also lose neutral SO2 and SO3 groups. For trimeric species with charge states of -3 and -4, IMS identifies three and two isomers, respectively. It was confirmed that the -4 charged trimer isomers consist of one with three stacked monomers and one in which the third monomer unit is connected to a stacked dimer via two iron-sulfonic bonds (bridged/stacked). Both yielded the same CID breakdown diagram confirming that the two isomers likely interconvert prior to dissociation. The significantly larger density of states of the bridged-stacked structure compared to the stacked structure means the former is likely the reactive configuration.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"49 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90814465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The emerging role of metal-organic coordination compounds in the development of electrochromic materials fueled a growing interest in both the development of the new systems and their effective integration into functional devices. Coordination complexes of late transition metals with polypyridine ligands, like 2’- bipyridine (bpy) and 2,2’:6’,2”-terpyridine (tpy) often feature bright colours as a result of strong metal-to-ligand charge transfer. These colours could be reversibly bleached by oxidation of the metal centre and restored upon the metal centre reduction. The colour and its intensity can be controlled in different ways: by changing the nature of the metal centre(s) and by structural modification of ligand(s); by the construction of various metal-organic motifs and embedding them into devices, as well as by controlled layer-by-layer growth of the coordination assemblies on the surface of interest. The versatility of the available molecular building blocks allows for the systematic programming of the desired properties of the metal-organic units that could be effectively translated into the devices. This makes polypyridine metal complexes advantageous candidates for the design of effective electrochromic materials. Here, we review the evolution of electrochromic materials and devices based on molecularly defined bpy and tpy coordination adducts of late transition metals integrated into functional electrochromic devices over the past decade.
{"title":"Polypyridine-Based Architectures for Smart Electrochromic and Energy Storage Materials","authors":"Nadia O. Laschuk, I. Ebralidze, Olena V. Zenkina","doi":"10.1139/cjc-2022-0268","DOIUrl":"https://doi.org/10.1139/cjc-2022-0268","url":null,"abstract":"The emerging role of metal-organic coordination compounds in the development of electrochromic materials fueled a growing interest in both the development of the new systems and their effective integration into functional devices. Coordination complexes of late transition metals with polypyridine ligands, like 2’- bipyridine (bpy) and 2,2’:6’,2”-terpyridine (tpy) often feature bright colours as a result of strong metal-to-ligand charge transfer. These colours could be reversibly bleached by oxidation of the metal centre and restored upon the metal centre reduction. The colour and its intensity can be controlled in different ways: by changing the nature of the metal centre(s) and by structural modification of ligand(s); by the construction of various metal-organic motifs and embedding them into devices, as well as by controlled layer-by-layer growth of the coordination assemblies on the surface of interest. The versatility of the available molecular building blocks allows for the systematic programming of the desired properties of the metal-organic units that could be effectively translated into the devices. This makes polypyridine metal complexes advantageous candidates for the design of effective electrochromic materials. Here, we review the evolution of electrochromic materials and devices based on molecularly defined bpy and tpy coordination adducts of late transition metals integrated into functional electrochromic devices over the past decade.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"70 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85829943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Metz, Tobias Böhmer, Ben Raunitschke, C. Marian
Recent experimental studies of a spiro-linked anthracenone (A)–naphthalene (N) compound (AN) in butyronitrile solution [Dobkowski et al., J. Phys. Chem. A 2019, 123, 6978] proposed an excited-state energy dissipation pathway {1ππ*(N)+1ππ*(A)}→1nπ*(A)→3nπ*(A)→3ππ*(N). However, a detailed theoretical study employing combined density functional theory and multireference configuration interaction methods, performed in the present work, suggests that the photoexcitation decay follows a different pathway. In butyronitrile solution, the intersystem crossing (ISC) follows the well-established El-Sayed rule and involves the 3ππ*(A) state which is found to be the lowest excited triplet state localized on the anthracenone moiety. Because the Dexter triplet excitation energy transfer (TEET) to the first excited triplet state of the naphthalene subunit is forbidden in C2v symmetry, it is mandatory to go beyond the Condon approximation in modeling this process. Non-adiabatic coupling matrix elementswere computed to obtain a TEET rate different from zero. Our calculations yield time constants of 5 ps for the 1nπ*(A)→3ππ*(A) ISC and of 3 ps for the subsequent 3ππ*(A)→3ππ*(N) TEET in butyronitrile whereas the energy dissipation involving the 3nπ*(A) state as an intermediate occurs on a much longer time scale.
一种螺链蒽酮(a) -萘(N)化合物(AN)在丁腈溶液中的实验研究[Dobkowski et al.， J. Phys。化学。A[2019,123, 6978]提出了一个激发态能量耗散路径{1ππ*(N)+1ππ*(A)}→1nπ*(A)→3nπ*(A)→3ππ*(N)。然而，采用密度泛函理论和多参考配置相互作用方法进行的详细理论研究表明，光激发衰变遵循不同的途径。在丁腈溶液中，系统间交叉(ISC)遵循公认的El-Sayed规则，涉及3ππ*(A)态，这是定位于蒽酮部分的最低激发态。由于在C2v对称中禁止Dexter三重态激发能转移(TEET)到萘亚基的第一激发态，因此在模拟这一过程时必须超越Condon近似。计算了非绝热耦合矩阵单元，得到了不同于零的TEET速率。我们的计算得到了丁腈中1nπ*(A)→3ππ*(A) ISC和随后的3ππ*(A)→3ππ*(N) TEET的时间常数为5 ps，而3nπ*(A)作为中间态的能量耗散发生在更长的时间尺度上。
{"title":"Intersystem Crossing and Intramolecular Triplet Excitation Energy Transfer in Spiro[9,10-dihydro-9-oxoanthracene-10,2´- 5´,6´-benzindan] Investigated by DFT/MRCI Methods","authors":"S. Metz, Tobias Böhmer, Ben Raunitschke, C. Marian","doi":"10.1139/cjc-2022-0259","DOIUrl":"https://doi.org/10.1139/cjc-2022-0259","url":null,"abstract":"Recent experimental studies of a spiro-linked anthracenone (A)–naphthalene (N) compound (AN) in butyronitrile solution [Dobkowski et al., J. Phys. Chem. A 2019, 123, 6978] proposed an excited-state energy dissipation pathway {1ππ*(N)+1ππ*(A)}→1nπ*(A)→3nπ*(A)→3ππ*(N). However, a detailed theoretical study employing combined density functional theory and multireference configuration interaction methods, performed in the present work, suggests that the photoexcitation decay follows a different pathway. In butyronitrile solution, the intersystem crossing (ISC) follows the well-established El-Sayed rule and involves the 3ππ*(A) state which is found to be the lowest excited triplet state localized on the anthracenone moiety. Because the Dexter triplet excitation energy transfer (TEET) to the first excited triplet state of the naphthalene subunit is forbidden in C2v symmetry, it is mandatory to go beyond the Condon approximation in modeling this process. Non-adiabatic coupling matrix elementswere computed to obtain a TEET rate different from zero. Our calculations yield time constants of 5 ps for the 1nπ*(A)→3ππ*(A) ISC and of 3 ps for the subsequent 3ππ*(A)→3ππ*(N) TEET in butyronitrile whereas the energy dissipation involving the 3nπ*(A) state as an intermediate occurs on a much longer time scale.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"34 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81518650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper aimed to reveal the effects of chemisorbed oxygen species on selective catalytic oxidation applied for H2S removal. A sequence of thermal treatments was conducted on V2O5/TiO2 samples to prepare catalysts that possessed different distributions of oxygen species. Characterization by X-ray photoelectron spectroscopy enabled a distinction among three different chemisorbed oxygen species: O–, O22–, and O2–. In addition, the dominance of the O– species, which is a very reactive oxygen species for catalytic oxidation reactions, was observed when the catalyst was exposed to 5%O2/N2 gas at the low temperature of 30 ℃. It was also found that the N400A30 with the highest ratio of O– species was superior to others at converting H2S into elemental sulfur over the whole range of temperatures: the best S yield of N400A30 was 85% at 130 oC. These results are promising, as thermal treatments for oxygen adsorption was adopted for the first time to improve the catalytic activity of H2S removal by modulating the proportion of highly reactive O– species.
{"title":"Enhancing catalytic activity of V2O5/TiO2 in H2S selective oxidation by modulating oxygen adsorption conditions","authors":"Hyunju Lee, Jae-Hwan Yang","doi":"10.1139/cjc-2022-0167","DOIUrl":"https://doi.org/10.1139/cjc-2022-0167","url":null,"abstract":"This paper aimed to reveal the effects of chemisorbed oxygen species on selective catalytic oxidation applied for H2S removal. A sequence of thermal treatments was conducted on V2O5/TiO2 samples to prepare catalysts that possessed different distributions of oxygen species. Characterization by X-ray photoelectron spectroscopy enabled a distinction among three different chemisorbed oxygen species: O–, O22–, and O2–. In addition, the dominance of the O– species, which is a very reactive oxygen species for catalytic oxidation reactions, was observed when the catalyst was exposed to 5%O2/N2 gas at the low temperature of 30 ℃. It was also found that the N400A30 with the highest ratio of O– species was superior to others at converting H2S into elemental sulfur over the whole range of temperatures: the best S yield of N400A30 was 85% at 130 oC. These results are promising, as thermal treatments for oxygen adsorption was adopted for the first time to improve the catalytic activity of H2S removal by modulating the proportion of highly reactive O– species.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"26 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91314123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wenli Zou, M. Freindorf, Vytor P Oliveira, Yunwen Tao, E. Kraka
We introduce in this work a unique parameter for the quantitative assessment of the intrinsic strength of the π–interaction between two monomers forming a complex. The new parameter is a local intermonomer stretching force constant, based on the local mode theory, originally developed by Konkoli and Cremer, and derived from the set of nine possible intermonomer normal vibrational modes. The new local force constant was applied to a diverse set of more than 70 molecular complexes, which was divided into four groups. Group 1 includes atoms, ions, and small molecules interacting with benzene substituted substituted benzenes. Group 2 includes transition metal hydrides and oxides interacting with benzene while Group 3 involves ferrocenes, chromocenes, and titanium sandwich compounds. Group 4 presents an extension to oxygen π–hole interactions in comparison with in-plane hydrogen bonding. We found that the strength of the π–interactions in these diverse molecular complexes can vary from weak interactions with predominantly electro-static character, found e.g., for argon-benzene complexes to strong interactions with a substantial covalent nature, found e.g., for ferrocenes; all being seamlessly described and compared with the new intermonomer local mode force constant, which also outperforms other descriptors such as an averaged force constant or a force constant guided by the electron density bond paths. We hope that our findings will inspire the community to apply the new parameter also to other intermonomer π–interactions, enriching in this way the broad field of organometallic chemistry with a new efficient assessment tool.
{"title":"Weak and strong π interactions between two monomers - assessed with local vibrational mode theory","authors":"Wenli Zou, M. Freindorf, Vytor P Oliveira, Yunwen Tao, E. Kraka","doi":"10.1139/cjc-2022-0254","DOIUrl":"https://doi.org/10.1139/cjc-2022-0254","url":null,"abstract":"We introduce in this work a unique parameter for the quantitative assessment of the intrinsic strength of the π–interaction between two monomers forming a complex. The new parameter is a local intermonomer stretching force constant, based on the local mode theory, originally developed by Konkoli and Cremer, and derived from the set of nine possible intermonomer normal vibrational modes. The new local force constant was applied to a diverse set of more than 70 molecular complexes, which was divided into four groups. Group 1 includes atoms, ions, and small molecules interacting with benzene substituted substituted benzenes. Group 2 includes transition metal hydrides and oxides interacting with benzene while Group 3 involves ferrocenes, chromocenes, and titanium sandwich compounds. Group 4 presents an extension to oxygen π–hole interactions in comparison with in-plane hydrogen bonding. We found that the strength of the π–interactions in these diverse molecular complexes can vary from weak interactions with predominantly electro-static character, found e.g., for argon-benzene complexes to strong interactions with a substantial covalent nature, found e.g., for ferrocenes; all being seamlessly described and compared with the new intermonomer local mode force constant, which also outperforms other descriptors such as an averaged force constant or a force constant guided by the electron density bond paths. We hope that our findings will inspire the community to apply the new parameter also to other intermonomer π–interactions, enriching in this way the broad field of organometallic chemistry with a new efficient assessment tool.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"48 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76186124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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