Phosphorus-containing polymer networks as precursors to polymer derived ceramics were prepared using a combination of three monomers (1,3,5-triallyl-1,3,5-triazine-2,4,6-trione or 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, tetraethyleneglycol diallyl ether, and isobutyl phosphine ). By varying the stoichiometry of these components, it was observed that key properties such as thermal stability, swellability and ceramic yield after pyrolysis can be modified at will. Optimal stoichiometries to achieve the highest ceramic yields upon pyrolysis, while maintaining swellability were determined. Cobalt was introduced into the networks by reaction of the tertiary phosphine fragments in the material with CpCo(CO)2. After pyrolysis of the metalated at 800 °C, the resulting ceramics were characterized using scanning electron microscopy-energy dispersive X-ray (SEM-EDX) and X-ray photoelectron spectroscopy (XPS).
{"title":"Synthesis and Characterization of Phosphorus Containing Polymers for the Generation of Polymer Derived Ceramics","authors":"Kelly C. Duggan, Ian C. Watson, P. Ragogna","doi":"10.1139/cjc-2022-0258","DOIUrl":"https://doi.org/10.1139/cjc-2022-0258","url":null,"abstract":"Phosphorus-containing polymer networks as precursors to polymer derived ceramics were prepared using a combination of three monomers (1,3,5-triallyl-1,3,5-triazine-2,4,6-trione or 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, tetraethyleneglycol diallyl ether, and isobutyl phosphine ). By varying the stoichiometry of these components, it was observed that key properties such as thermal stability, swellability and ceramic yield after pyrolysis can be modified at will. Optimal stoichiometries to achieve the highest ceramic yields upon pyrolysis, while maintaining swellability were determined. Cobalt was introduced into the networks by reaction of the tertiary phosphine fragments in the material with CpCo(CO)2. After pyrolysis of the metalated at 800 °C, the resulting ceramics were characterized using scanning electron microscopy-energy dispersive X-ray (SEM-EDX) and X-ray photoelectron spectroscopy (XPS).","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79836199","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}
Ayaka Ueda, Kazuma Amaike, Yoko Shirotani, Robin Warstat, Hideto Ito, Jae-Hoon Choi, H. Kawagishi, K. Itami
Imidazole-4-carboxamide (ICA), which is one of a group of “fairy chemicals” (FCs) that cause the fairy ring phenomena, has plant growth inhibitory activity. FCs have the potential as candidates for a new family of plant hormones as they have been found endogenously in all plant species tested, and show growth-regulating activity against the plants. While basic research on FCs is progressing, they are also expected to be applied not only to agrochemicals but also as pharmaceuticals. Derivatization of one of FCs, 2-azahypoxanthine (AHX) and the structure-activity relationship (SAR) studies have clarified its activity as a plant growth promoter. Yet, imidazole-4-carboxamide (ICA) has not been derivatized at all and SAR regarding its activity remains unknown. In this study, we synthesized the derivatives of ICA by direct C-H arylation of ICA precursors and evaluated its activity in rice. The 12 total compounds including the arylated ICAs and their precursors were evaluated for root and shoot elongation in rice, resulting in the discovery that a number of compounds unexpectedly have an elongation activity in the root and shoot.
{"title":"C-H arylation enables synthesis of imidazole-4-carboxamide (ICA) based fairy chemicals with plant growth promoting activity","authors":"Ayaka Ueda, Kazuma Amaike, Yoko Shirotani, Robin Warstat, Hideto Ito, Jae-Hoon Choi, H. Kawagishi, K. Itami","doi":"10.1139/cjc-2022-0256","DOIUrl":"https://doi.org/10.1139/cjc-2022-0256","url":null,"abstract":"Imidazole-4-carboxamide (ICA), which is one of a group of “fairy chemicals” (FCs) that cause the fairy ring phenomena, has plant growth inhibitory activity. FCs have the potential as candidates for a new family of plant hormones as they have been found endogenously in all plant species tested, and show growth-regulating activity against the plants. While basic research on FCs is progressing, they are also expected to be applied not only to agrochemicals but also as pharmaceuticals. Derivatization of one of FCs, 2-azahypoxanthine (AHX) and the structure-activity relationship (SAR) studies have clarified its activity as a plant growth promoter. Yet, imidazole-4-carboxamide (ICA) has not been derivatized at all and SAR regarding its activity remains unknown. In this study, we synthesized the derivatives of ICA by direct C-H arylation of ICA precursors and evaluated its activity in rice. The 12 total compounds including the arylated ICAs and their precursors were evaluated for root and shoot elongation in rice, resulting in the discovery that a number of compounds unexpectedly have an elongation activity in the root and shoot.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"2016 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86328411","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. Baird, C. Vogels, S. Geier, Lara K. Watanabe, J. Binder, C. L. Macdonald, S. Westcott
This study reports on the exploration of the phosphinoboration reaction with several thiosemicarbazones (R5R4NC(S)NR3N=CR1R2). Reactions between either Ph2PBpin (pin = 1,2-O2C2Me4) or Ph2PBcat (cat = 1,2-O2C6H4) with thiosemicarbazones containing a terminal primary or secondary amine afforded boron-containing heterocyclic 1,3,4-thiadiazoline products in excellent yield. The addition of Ph2PBpin to thiosemicarbazones containing an NMe2 group in the terminal position generated novel five-membered heterocycles in moderate yield, which included boron, sulfur, and nitrogen atoms. Heterocyclization of the thiosemicarbazones occurs preferentially in the presence of functional groups such as acetyl and pyridyl groups.
{"title":"The phosphinoboration of thiosemicarbazones","authors":"S. Baird, C. Vogels, S. Geier, Lara K. Watanabe, J. Binder, C. L. Macdonald, S. Westcott","doi":"10.1139/cjc-2022-0088","DOIUrl":"https://doi.org/10.1139/cjc-2022-0088","url":null,"abstract":"This study reports on the exploration of the phosphinoboration reaction with several thiosemicarbazones (R5R4NC(S)NR3N=CR1R2). Reactions between either Ph2PBpin (pin = 1,2-O2C2Me4) or Ph2PBcat (cat = 1,2-O2C6H4) with thiosemicarbazones containing a terminal primary or secondary amine afforded boron-containing heterocyclic 1,3,4-thiadiazoline products in excellent yield. The addition of Ph2PBpin to thiosemicarbazones containing an NMe2 group in the terminal position generated novel five-membered heterocycles in moderate yield, which included boron, sulfur, and nitrogen atoms. Heterocyclization of the thiosemicarbazones occurs preferentially in the presence of functional groups such as acetyl and pyridyl groups.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83007270","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}
Trolox-C (TXC) is a water-soluble analogue of α-tocopherol that reduces the metal-bound superoxo complex, [(NH3)5Co(µ-O2)Co(NH3)5]5+ (SOC) in water-ethanol media. In aqueous-acid media ([H+] = 0.02–0.70 M), TXC quantitatively reduces SOC under the pseudo first-order reaction condition where the concentration of TXC, [TXC] was at least ten times or more than that of [SOC]. Variations in media ionic strength suggests for the reaction between two cationic species and a positive kinetic isotope effect (kH/kD <1) indicates for a pre-equilibrium step of protonation of the pyran-oxygen of TXC. Both TXC and the protonated TXC, i.e., TXCH are the potential reductants under the experimental range of media acidity. The reduction of SOC takes place through the single electron transfer (SET) and the kinetic analysis yields the value for second-order rate constants for TXC and TXCH as 9.7 and 3.6×103 M-1s-1 at 15 ºC.
{"title":"Mechanistic Approach to the Anti-Oxidant Activities of Metal-Associated Superoxide With Trolox","authors":"Bula Singh, Ranendu Sekhar Das","doi":"10.1139/cjc-2022-0189","DOIUrl":"https://doi.org/10.1139/cjc-2022-0189","url":null,"abstract":"Trolox-C (TXC) is a water-soluble analogue of α-tocopherol that reduces the metal-bound superoxo complex, [(NH3)5Co(µ-O2)Co(NH3)5]5+ (SOC) in water-ethanol media. In aqueous-acid media ([H+] = 0.02–0.70 M), TXC quantitatively reduces SOC under the pseudo first-order reaction condition where the concentration of TXC, [TXC] was at least ten times or more than that of [SOC]. Variations in media ionic strength suggests for the reaction between two cationic species and a positive kinetic isotope effect (kH/kD <1) indicates for a pre-equilibrium step of protonation of the pyran-oxygen of TXC. Both TXC and the protonated TXC, i.e., TXCH are the potential reductants under the experimental range of media acidity. The reduction of SOC takes place through the single electron transfer (SET) and the kinetic analysis yields the value for second-order rate constants for TXC and TXCH as 9.7 and 3.6×103 M-1s-1 at 15 ºC.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"15 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74992686","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}
Takeshi Sato, Himadri Pathak, Y. Orimo, K. Ishikawa
We review the time-dependent multiconfiguration self-consistent-field (TD-MCSCF) method and the time-dependent optimized coupled-cluster (TD-OCC) method for first-principles simulations of high-field phenomena such as tunneling ionization and high-order harmonic generation in atoms and molecules irradiated by a strong laser field. These methods provide a flexible and systematically improvable description of the multielectron dynamics by expressing the all-electron wavefunction by configuration interaction expansion or coupled-cluster expansion, using time-dependent one-electron orbital functions. The time-dependent variational principle plays a key role to derive these methods satisfying gauge invariance and Ehrenfest theorem. The real-time/real-space implementation with an absorbing boundary condition enables the simulation of high-field processes involving multiple excitation and ionization. We present a detailed, comprehensive discussion of such features of TD-MCSCF and TD-OCC methods.
{"title":"Time-dependent multiconfiguration self-consistent-field and time-dependent optimized coupled-cluster methods for intense laser-driven multielectron dynamics","authors":"Takeshi Sato, Himadri Pathak, Y. Orimo, K. Ishikawa","doi":"10.1139/cjc-2022-0297","DOIUrl":"https://doi.org/10.1139/cjc-2022-0297","url":null,"abstract":"We review the time-dependent multiconfiguration self-consistent-field (TD-MCSCF) method and the time-dependent optimized coupled-cluster (TD-OCC) method for first-principles simulations of high-field phenomena such as tunneling ionization and high-order harmonic generation in atoms and molecules irradiated by a strong laser field. These methods provide a flexible and systematically improvable description of the multielectron dynamics by expressing the all-electron wavefunction by configuration interaction expansion or coupled-cluster expansion, using time-dependent one-electron orbital functions. The time-dependent variational principle plays a key role to derive these methods satisfying gauge invariance and Ehrenfest theorem. The real-time/real-space implementation with an absorbing boundary condition enables the simulation of high-field processes involving multiple excitation and ionization. We present a detailed, comprehensive discussion of such features of TD-MCSCF and TD-OCC methods.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"39 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89115106","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 enzyme malonamidase E2 catalytically hydrolyses malonamate (MLA) into malonate and ammonia. Its active site contains an uncommon Ser-cisSer-Lys catalytic triad that is critical to its functioning. Mutations of the residues in this triad can not only provide insight into its key features but can also potentially identify how it may be influenced or adapted, i.e., decreased or increased. In this study, the effects of single and double Ser/Cys exchanges on the wildtype Ser155-cisSer131-Lys62 catalytic triad (i.e., Cys155-cisSer131-Lys62 (S155C), Ser155-cisCys131-Lys62 (S131C), and Cys155-cisCys131-Lys62 (S131C/S155C)) were examined. In particular, the dynamics and stability of the resulting substituted triads was examined along with their inter-triad residue hydrogen bonding interactions as well as those with other nearby residues and the MLA substrate. The present results suggest that some mutations are more impactful than others. Indeed, mutation of cisSer131 to cisCys131 disrupts the triad and causes inconsistent hydrogen bonding interactions among the triad residues (i.e., Ser155, Cys131, and Lys62). In contrast, in the double mutant Cys155-cisCys131-Lys62, the triad’s residues appear to exhibit greater conformation stability with more consistent hydrogen bond interactions, though not necessarily as in the wildtype.
{"title":"A molecular dynamics simulations investigation on the effects of Ser/Cys exchange in the Ser-cisSer-Lys catalytic triad of Malonamidase E2","authors":"A. Roy, J. Gauld","doi":"10.1139/cjc-2022-0140","DOIUrl":"https://doi.org/10.1139/cjc-2022-0140","url":null,"abstract":"The enzyme malonamidase E2 catalytically hydrolyses malonamate (MLA) into malonate and ammonia. Its active site contains an uncommon Ser-cisSer-Lys catalytic triad that is critical to its functioning. Mutations of the residues in this triad can not only provide insight into its key features but can also potentially identify how it may be influenced or adapted, i.e., decreased or increased. In this study, the effects of single and double Ser/Cys exchanges on the wildtype Ser155-cisSer131-Lys62 catalytic triad (i.e., Cys155-cisSer131-Lys62 (S155C), Ser155-cisCys131-Lys62 (S131C), and Cys155-cisCys131-Lys62 (S131C/S155C)) were examined. In particular, the dynamics and stability of the resulting substituted triads was examined along with their inter-triad residue hydrogen bonding interactions as well as those with other nearby residues and the MLA substrate. The present results suggest that some mutations are more impactful than others. Indeed, mutation of cisSer131 to cisCys131 disrupts the triad and causes inconsistent hydrogen bonding interactions among the triad residues (i.e., Ser155, Cys131, and Lys62). In contrast, in the double mutant Cys155-cisCys131-Lys62, the triad’s residues appear to exhibit greater conformation stability with more consistent hydrogen bond interactions, though not necessarily as in the wildtype.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"4 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84075760","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}
Monte Carlo multi-track chemistry simulations were used in combination with a cylindrical, “instantaneous pulse” irradiation model to study the effect of high dose rates on the early, transient yields (G values) of the “primary products” (e-aq, H•, H2, •OH, H2O2, H3O+, OH-,…) of the radiolysis of supercritical water (SCW) at 400 °C and 25 MPa pressure. Our simulation model consisted of randomly irradiating SCW with single pulses of N incident 300-MeV protons, which mimic the low linear energy transfer of 60Co γ/fast electron irradiations. The effect of dose rate was studied by varying N. Generally, high dose rates were found to favor radical-radical reactions, which increases the proportion of the molecular products at the expense of the radical products. However, as an exception, G(H•) increases with increasing dose rate in the track stage of radiolysis, predominantly due to the reaction of hydrated electrons with hydronium ions (H3O+). In addition, the generation of acidic spikes due to proton transfer reactions in the physicochemical stage was also examined. Interestingly, an early, transient, very acidic (pH ~ 3.5) response was observed at high radiation dose rates across the entire irradiated volume. The present work raises the question of whether the potential oxidizing species •OH and H2O2 and these highly acidic pH spikes at high dose rates could promote a corrosive environment under proposed Generation-IV SCW-cooled reactor or small modular reactor operating conditions that would lead to progressive degradation of materials.
{"title":"Effect of very high dose rates on the radiolysis of supercritical water at 400 °C and 25 MPa","authors":"A. Sultana, J. Meesungnoen, J. Jay-Gerin","doi":"10.1139/cjc-2022-0210","DOIUrl":"https://doi.org/10.1139/cjc-2022-0210","url":null,"abstract":"Monte Carlo multi-track chemistry simulations were used in combination with a cylindrical, “instantaneous pulse” irradiation model to study the effect of high dose rates on the early, transient yields (G values) of the “primary products” (e-aq, H•, H2, •OH, H2O2, H3O+, OH-,…) of the radiolysis of supercritical water (SCW) at 400 °C and 25 MPa pressure. Our simulation model consisted of randomly irradiating SCW with single pulses of N incident 300-MeV protons, which mimic the low linear energy transfer of 60Co γ/fast electron irradiations. The effect of dose rate was studied by varying N. Generally, high dose rates were found to favor radical-radical reactions, which increases the proportion of the molecular products at the expense of the radical products. However, as an exception, G(H•) increases with increasing dose rate in the track stage of radiolysis, predominantly due to the reaction of hydrated electrons with hydronium ions (H3O+). In addition, the generation of acidic spikes due to proton transfer reactions in the physicochemical stage was also examined. Interestingly, an early, transient, very acidic (pH ~ 3.5) response was observed at high radiation dose rates across the entire irradiated volume. The present work raises the question of whether the potential oxidizing species •OH and H2O2 and these highly acidic pH spikes at high dose rates could promote a corrosive environment under proposed Generation-IV SCW-cooled reactor or small modular reactor operating conditions that would lead to progressive degradation of materials.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"48 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78208011","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}
Mozhgan Khorasani Motlagh, M. Noroozifar, H. Kraatz
Gold (Au) and glassy carbon (GC) electrodes have been decorated with gold nanodendrites (NDs) using galvanic replacement reactions. Modification of the ND surfaces by lipoic acid N-hydroxysuccinimide ester allows to immobilise selenate reductase (SeR) to the electrode surface, rendering it selective for the catalytic reduction of selenate (SeO42-, Se(VI)) to selenite (SeO32-, Se(IV)). Electrode modifications have been characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). For selenate detection, CV and differential pulse voltammetry (DPV) measurements have been carried out in HEPES buffer with pH 6.0. Under optimum conditions, the linear range for Au electrodes decorated with AuNDs was 0.3-203 µg/L Se with a limit of detection of 0.01 µg/L Se, which is a 274-fold improvement over using non-nanostructured surfaces for selenate detection. Other anions such as SO42−, NO3-, NO2-, PO43-, AsO43- and SeO32- did not interfere with the detection of selenate. The electrochemical sensor was used for the detection of selenate in three different real samples with recovery between 98.5-102.0%.
{"title":"Highly sensitive and selective detection of selenate in water samples using an enzymatic gold nanodendrite biosensor","authors":"Mozhgan Khorasani Motlagh, M. Noroozifar, H. Kraatz","doi":"10.1139/cjc-2022-0220","DOIUrl":"https://doi.org/10.1139/cjc-2022-0220","url":null,"abstract":"Gold (Au) and glassy carbon (GC) electrodes have been decorated with gold nanodendrites (NDs) using galvanic replacement reactions. Modification of the ND surfaces by lipoic acid N-hydroxysuccinimide ester allows to immobilise selenate reductase (SeR) to the electrode surface, rendering it selective for the catalytic reduction of selenate (SeO42-, Se(VI)) to selenite (SeO32-, Se(IV)). Electrode modifications have been characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). For selenate detection, CV and differential pulse voltammetry (DPV) measurements have been carried out in HEPES buffer with pH 6.0. Under optimum conditions, the linear range for Au electrodes decorated with AuNDs was 0.3-203 µg/L Se with a limit of detection of 0.01 µg/L Se, which is a 274-fold improvement over using non-nanostructured surfaces for selenate detection. Other anions such as SO42−, NO3-, NO2-, PO43-, AsO43- and SeO32- did not interfere with the detection of selenate. The electrochemical sensor was used for the detection of selenate in three different real samples with recovery between 98.5-102.0%.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"176 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73444955","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}
Two types of Sm(II) complexes bearing either an N-phosphine-oxide-substituted imidazolylidene (PoxIm) or the corresponding imidazolinylidene (SPoxIm) were successfully prepared and characterized using single crystal X-ray diffraction analysis. The general formula of the structures of the complexes was found to be (anti--O-(S)PoxIm)nSmX2(THF)m where X = I, n = 2, m = 2 or X = pentamethylcyclopentadienyl, n = 1, m = 0. The carbene carbon atoms remained intact in these complexes. In some cases, axial chirality was clearly induced around the N‒P bonds due to the restricted rotation of the N-phosphinoyl moieties, which arises from the formation of N-phosphinoyl oxygen‒Sm(II) bonds. This work highlights a rare example of complexation-induced N‒P axial chirality and new aspects regarding lanthanide complexes of multifunctional multipurpose carbenes.
成功制备了两种含n -膦氧化物取代咪唑酰基(PoxIm)和相应的咪唑酰基(SPoxIm)的Sm(II)配合物，并用单晶x射线衍射分析对其进行了表征。该配合物的结构通式为(anti-- o -(S)PoxIm)nSmX2(THF)m，其中X = I, n = 2, m = 2或X =五甲基环戊二烯，n = 1, m = 0。碳原子在这些配合物中保持完整。在某些情况下，由于n -磷酰氧- sm (II)键的形成导致n -磷酰氧- sm (II)键的n -磷酰基部分旋转受限，在N-P键周围明显诱导了轴向手性。这项工作突出了络合诱导的N-P轴向手性的罕见例子和关于多功能多用途碳烯的镧系配合物的新方面。
{"title":"Complexation-Induced N‒P Axial Chirality in Sm(II) N-Phosphine-Oxide-Substituted Imidazolylidene and Imidazolinylidene Complexes","authors":"Y. Hoshimoto, Y. Yamauchi, T. Terada, S. Ogoshi","doi":"10.1139/cjc-2022-0249","DOIUrl":"https://doi.org/10.1139/cjc-2022-0249","url":null,"abstract":"Two types of Sm(II) complexes bearing either an N-phosphine-oxide-substituted imidazolylidene (PoxIm) or the corresponding imidazolinylidene (SPoxIm) were successfully prepared and characterized using single crystal X-ray diffraction analysis. The general formula of the structures of the complexes was found to be (anti--O-(S)PoxIm)nSmX2(THF)m where X = I, n = 2, m = 2 or X = pentamethylcyclopentadienyl, n = 1, m = 0. The carbene carbon atoms remained intact in these complexes. In some cases, axial chirality was clearly induced around the N‒P bonds due to the restricted rotation of the N-phosphinoyl moieties, which arises from the formation of N-phosphinoyl oxygen‒Sm(II) bonds. This work highlights a rare example of complexation-induced N‒P axial chirality and new aspects regarding lanthanide complexes of multifunctional multipurpose carbenes.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"32 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77762334","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 work describes a new method for the preparation of copper N-Heterocyclic Carbene (NHC) complexes which is conducted under air with mild conditions, using bench stable precursors and a weak base (NEt3). Under optimized conditions, the complexes were prepared in short reaction times of one hour, giving moderate to good yields after purification by column chromatography. Commonly utilized NHC-HCl salts were found to be applicable reacting with CuCl or CuI giving [(NHC)CuX] type complexes (X = Cl, I). This study adds to the growing literature in the preparation of catalytically relevant transition metal NHC complexes under mild and operationally simple conditions.
{"title":"Convenient Preparation of Copper (I) N-Heterocyclic Carbene Complexes Under Mild Conditions","authors":"Meilin Q. Lim, Eric C. Keske","doi":"10.1139/cjc-2022-0229","DOIUrl":"https://doi.org/10.1139/cjc-2022-0229","url":null,"abstract":"This work describes a new method for the preparation of copper N-Heterocyclic Carbene (NHC) complexes which is conducted under air with mild conditions, using bench stable precursors and a weak base (NEt3). Under optimized conditions, the complexes were prepared in short reaction times of one hour, giving moderate to good yields after purification by column chromatography. Commonly utilized NHC-HCl salts were found to be applicable reacting with CuCl or CuI giving [(NHC)CuX] type complexes (X = Cl, I). This study adds to the growing literature in the preparation of catalytically relevant transition metal NHC complexes under mild and operationally simple conditions.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"33 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84628823","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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