Here, a series of semi-interpenetrating polymer network (semi-IPN) hydrogels were synthesized and investigated by combining three materials such as N-isopropylacrylamide (NIPAM), N,N′-diethylacrylamide (DEA), and acrylic acid (AAc). The linear copolymer p(NIPAM-co-AAc) was introduced into DEA solution in the presence of N,N′-methylenebisacrylamide to synthesize p(NIPAM-co-AAc)/pDEA semi-IPN hydrogels using free radical polymerization. Scanning electron microscope images demonstrated the porous morphology of hydrogels with pore sizes in the range of 220–969 µm. The physicochemical properties of polymers were evaluated by various characterization techniques, including gel permeation chromatography, dynamic light scattering, differential scanning calorimetry, rheological measurement, mechanical properties, and swelling behaviors. The results indicated that the introduction of linear copolymers into conventional hydrogels has significantly improved the properties of the hydrogels. Besides, the use of NIPAM has significantly improved the thermal sensitivity of the polymers in this work. Finally, a selected semi-IPN hydrogel was evaluated for its potential for the drug release of paracetamol. The sorption of paracetamol was an exothermic process that obeyed the Freundlich isotherms, with the highest sorption of 119.57 mg/g. The paracetamol release followed the Korsmeyer–Peppas model and was consistent with the Fickian diffusion mechanism.
{"title":"Characterization and swelling behavior of hydrogels from N-isopropylacrylamide, N,N′-diethylacrylamide, acrylic acid, and its use for drug release","authors":"Huynh Nguyen Anh Tuan, H. Phuong","doi":"10.1139/cjc-2023-0019","DOIUrl":"https://doi.org/10.1139/cjc-2023-0019","url":null,"abstract":"Here, a series of semi-interpenetrating polymer network (semi-IPN) hydrogels were synthesized and investigated by combining three materials such as N-isopropylacrylamide (NIPAM), N,N′-diethylacrylamide (DEA), and acrylic acid (AAc). The linear copolymer p(NIPAM-co-AAc) was introduced into DEA solution in the presence of N,N′-methylenebisacrylamide to synthesize p(NIPAM-co-AAc)/pDEA semi-IPN hydrogels using free radical polymerization. Scanning electron microscope images demonstrated the porous morphology of hydrogels with pore sizes in the range of 220–969 µm. The physicochemical properties of polymers were evaluated by various characterization techniques, including gel permeation chromatography, dynamic light scattering, differential scanning calorimetry, rheological measurement, mechanical properties, and swelling behaviors. The results indicated that the introduction of linear copolymers into conventional hydrogels has significantly improved the properties of the hydrogels. Besides, the use of NIPAM has significantly improved the thermal sensitivity of the polymers in this work. Finally, a selected semi-IPN hydrogel was evaluated for its potential for the drug release of paracetamol. The sorption of paracetamol was an exothermic process that obeyed the Freundlich isotherms, with the highest sorption of 119.57 mg/g. The paracetamol release followed the Korsmeyer–Peppas model and was consistent with the Fickian diffusion mechanism.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"145 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86643214","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}
Yunju Zhang, Yong-guo Liu, Meilian Zhao, Yuxi Sun, Shuxin Liu
The catalytic influence of water molecules on BrO + CH2O reaction was discussed through the investigation of mechanism and kinetics. The potential energy surfaces and dynamic properties of the BrO + CH2O reaction were investigated at the CCSD(T)/aug-cc-pVTZ//B3LYP/cc-pVTZ level. The reaction generates four different products, respectively, through four pathways without water and nine pathways with water. The results have shown that the generation of HCO + HOBr occupied the entire reaction without water. The rate constants were obtained by employing the KisThelP program based on the Transition State Theory with Wigner tunneling correction. This rate constants of the naked reaction are lower than that in the presence of monomolecular water and are higher than that in the presence of bimolecular water. The current calculations indicated that monomolecular water could accelerate the BrO + CH2O reaction, while bimolecular water could not accelerate the BrO + CH2O reaction. The effective rate constants (in the presence of monomolecular water and bimolecular water) are much lower than that of the naked reaction.
{"title":"The influence of monomolecular water and bimolecular water on BrO + CH2O reaction","authors":"Yunju Zhang, Yong-guo Liu, Meilian Zhao, Yuxi Sun, Shuxin Liu","doi":"10.1139/cjc-2022-0237","DOIUrl":"https://doi.org/10.1139/cjc-2022-0237","url":null,"abstract":"The catalytic influence of water molecules on BrO + CH2O reaction was discussed through the investigation of mechanism and kinetics. The potential energy surfaces and dynamic properties of the BrO + CH2O reaction were investigated at the CCSD(T)/aug-cc-pVTZ//B3LYP/cc-pVTZ level. The reaction generates four different products, respectively, through four pathways without water and nine pathways with water. The results have shown that the generation of HCO + HOBr occupied the entire reaction without water. The rate constants were obtained by employing the KisThelP program based on the Transition State Theory with Wigner tunneling correction. This rate constants of the naked reaction are lower than that in the presence of monomolecular water and are higher than that in the presence of bimolecular water. The current calculations indicated that monomolecular water could accelerate the BrO + CH2O reaction, while bimolecular water could not accelerate the BrO + CH2O reaction. The effective rate constants (in the presence of monomolecular water and bimolecular water) are much lower than that of the naked reaction.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"41 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85555184","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}
Mélanie Sollin, S. Hosseininasab, J. Malenfant, Mohamed EL-akhrass, Amaia Lopez de Arbina, Alicia Montulet, M. Frenette
Organic and biological molecules with relatively weak C-H bonds can react with O2 via a free-radical reaction called autoxidation. The primary products of these peroxyl-radical-driven reactions are hydroperoxides, R2CHOOH. If autoxidation continues, the secondary oxidation of hydroperoxides is known to form ketones, R2C=O, but this mechanism is not well characterized. Importantly, we find that ketone formation produces a highly reactive hydroxyl radical, HO•. We can trap HO• using benzene as a solvent to form quantifiable amounts of phenol. Fluorene was chosen as a model system to study this secondary oxidation in great detail. Kinetic modeling allowed the measurement of rate constants for the primary and secondary autoxidation reactions as 11.3 M-1s-1 and 25 M-1s-1, respectively. DFT modeling likewise predicts a faster oxidation for the secondary autoxidation. This type of kinetic measurement and modeling approach could be useful to study the autoxidation of plastics, petrochemicals, and lipids.
{"title":"Oxidation of Secondary Hydroperoxides via αC-H Abstraction to Form Ketones and Hydroxyl Radicals: Fluorene Autoxidation as a Model System","authors":"Mélanie Sollin, S. Hosseininasab, J. Malenfant, Mohamed EL-akhrass, Amaia Lopez de Arbina, Alicia Montulet, M. Frenette","doi":"10.1139/cjc-2022-0089","DOIUrl":"https://doi.org/10.1139/cjc-2022-0089","url":null,"abstract":"Organic and biological molecules with relatively weak C-H bonds can react with O2 via a free-radical reaction called autoxidation. The primary products of these peroxyl-radical-driven reactions are hydroperoxides, R2CHOOH. If autoxidation continues, the secondary oxidation of hydroperoxides is known to form ketones, R2C=O, but this mechanism is not well characterized. Importantly, we find that ketone formation produces a highly reactive hydroxyl radical, HO•. We can trap HO• using benzene as a solvent to form quantifiable amounts of phenol. Fluorene was chosen as a model system to study this secondary oxidation in great detail. Kinetic modeling allowed the measurement of rate constants for the primary and secondary autoxidation reactions as 11.3 M-1s-1 and 25 M-1s-1, respectively. DFT modeling likewise predicts a faster oxidation for the secondary autoxidation. This type of kinetic measurement and modeling approach could be useful to study the autoxidation of plastics, petrochemicals, and lipids.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"11 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88573389","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 use of pulsed laser-induced dewetting (PLiD) is reported as a novel approach in the fabrication of Au nanoparticle (NP) catalytic arrays for the growth of Si nanowires (NWs) by chemical vapor deposition using SiCl4in the presence of H2. On polished Si substrates, PLiD generates Au NP catalysts with long-range order and narrow size distributions. It has been shown that the monodispersed distribution of Au NPs provides consistent diameter control of the as-grown Si NWs. A systematic exploration of the Si NW synthesis time, temperature and gas flow rates illustrates a level of tunability in terms of morphology, be it arrayed or entangled Si NWs, with varying experimental parameters. An investigation of the effect of growth temperature also showed that Si NWs can be synthesized at temperatures as low as 700 ⁰C when using SiCl4 as the precursor. The use of porous Si substrates enabled direct observation of the diameter-dependent growth due to the simultaneous presence of three Au NP size distributions. Growth from the small- and medium-size Au NP catalysts occurred first, followed by that from the large-size Au NPs, which was only observed at extended times or high SiCl4 flow rates. The delayed onset of growth from the large-size Au NPs is due to the longer time to achieve Si super-saturation of larger catalyst NPs. The morphology and diameter control of the as-grown Si NWs reported in this work makes this approach potentially useful towards applications such as nanoelectronics, sensors, and LIB electrodes depending on the desired morphology.
{"title":"Arrayed and Entangled Silicon Nanowires Using Au Nanoparticle Catalysts Prepared by Pulsed Laser-induced Dewetting","authors":"Alison Joy Fulton, Yujun Shi","doi":"10.1139/cjc-2023-0047","DOIUrl":"https://doi.org/10.1139/cjc-2023-0047","url":null,"abstract":"The use of pulsed laser-induced dewetting (PLiD) is reported as a novel approach in the fabrication of Au nanoparticle (NP) catalytic arrays for the growth of Si nanowires (NWs) by chemical vapor deposition using SiCl4in the presence of H2. On polished Si substrates, PLiD generates Au NP catalysts with long-range order and narrow size distributions. It has been shown that the monodispersed distribution of Au NPs provides consistent diameter control of the as-grown Si NWs. A systematic exploration of the Si NW synthesis time, temperature and gas flow rates illustrates a level of tunability in terms of morphology, be it arrayed or entangled Si NWs, with varying experimental parameters. An investigation of the effect of growth temperature also showed that Si NWs can be synthesized at temperatures as low as 700 ⁰C when using SiCl4 as the precursor. The use of porous Si substrates enabled direct observation of the diameter-dependent growth due to the simultaneous presence of three Au NP size distributions. Growth from the small- and medium-size Au NP catalysts occurred first, followed by that from the large-size Au NPs, which was only observed at extended times or high SiCl4 flow rates. The delayed onset of growth from the large-size Au NPs is due to the longer time to achieve Si super-saturation of larger catalyst NPs. The morphology and diameter control of the as-grown Si NWs reported in this work makes this approach potentially useful towards applications such as nanoelectronics, sensors, and LIB electrodes depending on the desired morphology.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"35 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77078559","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}
{"title":"Introduction to the WATOC Special Issue","authors":"R. J. Boyd, Alex Brown, G. DiLabio, S. Wetmore","doi":"10.1139/cjc-2023-0078","DOIUrl":"https://doi.org/10.1139/cjc-2023-0078","url":null,"abstract":"","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"9 2 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78329761","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}
Khandra Barrett, Matthew Dupuis, Anna Crossman, SunMin Park, T. George, C. Vogels, Jillian Rourke, Jason D. Masuda, S. Westcott
A series of iminopyridine ligands were prepared from the condensation reaction of 6-methylpyridine-2-carboxaldehyde and long chain aliphatic primary amines. Square planar platinum(II) complexes were synthesized from the reaction of [PtCl2(η2-coe)]2 (coe = cis-cyclooctene) with two equivalents of ligand. The synthesis of the platinum compounds appears to go through a 5-coordinate trigonal pyramidal species where coe remains coordinated initially but eventually dissociates to afford the 4-coordinate complexes. Ligands and platinum complexes were characterized using multi-nuclear NMR and FT-IR spectroscopies as well as an X-ray diffraction study for the platinum complex derived from n-hexylamine. The cytotoxic properties of the platinum complexes against the ovarian cancer cell line SKOV-3 using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric method were examined. Relative cytotoxicities of the platinum complexes follow a trend of greater potency with increasing chain length against the SKOV-3 cell line, with the longest aliphatic hydrocarbon chain (C16) exhibiting anticancer effects comparable to that of cisplatin.
{"title":"Synthesis, characterization, and anticancer properties of iminopyridine platinum(II) complexes containing long aliphatic chains‡","authors":"Khandra Barrett, Matthew Dupuis, Anna Crossman, SunMin Park, T. George, C. Vogels, Jillian Rourke, Jason D. Masuda, S. Westcott","doi":"10.1139/cjc-2023-0031","DOIUrl":"https://doi.org/10.1139/cjc-2023-0031","url":null,"abstract":"A series of iminopyridine ligands were prepared from the condensation reaction of 6-methylpyridine-2-carboxaldehyde and long chain aliphatic primary amines. Square planar platinum(II) complexes were synthesized from the reaction of [PtCl2(η2-coe)]2 (coe = cis-cyclooctene) with two equivalents of ligand. The synthesis of the platinum compounds appears to go through a 5-coordinate trigonal pyramidal species where coe remains coordinated initially but eventually dissociates to afford the 4-coordinate complexes. Ligands and platinum complexes were characterized using multi-nuclear NMR and FT-IR spectroscopies as well as an X-ray diffraction study for the platinum complex derived from n-hexylamine. The cytotoxic properties of the platinum complexes against the ovarian cancer cell line SKOV-3 using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric method were examined. Relative cytotoxicities of the platinum complexes follow a trend of greater potency with increasing chain length against the SKOV-3 cell line, with the longest aliphatic hydrocarbon chain (C16) exhibiting anticancer effects comparable to that of cisplatin.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"550 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77202532","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 comprehensive characterization of key mechanisms underlying signal transmission within the human brain remains an unsolved problem. The neuronal surface, composed principally of phosphatidylcholine (POPC), has a known ordering effect on water. This produces highly organized water layers (OWLs) at the neuron–water interface—the neurochemical implications of which are not currently understood. The human brain is 75% water by volume, with folds and grooves to maximize surface area, suggesting that characterization of neuronal OWLs may contribute to an understanding of neuronal signal transmission. Previous experimental work has measured enhanced conductivity of POPC OWLs relative to bulk water. The mechanism underlying this conductivity is still debated. Using quantum chemical methods on a POPC–water interface model system, we present data characterizing OWL conductance. Non-equilibrium Green's function calculation results demonstrate that there is negligible electron transfer-based conductivity through the OWL at biological temperatures. This is consistent with existing studies suggesting the Grotthuss mechanism as the most likely explanation for experimentally observed enhanced conductivity at the POPC–water interface. The broader implications of enhanced proton conductivity at the neuron–water interface are discussed.
{"title":"Assessing electron conduction mechanisms in highly organized surface water on a model neuronal lipid using quantum chemical methods","authors":"Mathew P. Neal, D. Weaver","doi":"10.1139/cjc-2023-0036","DOIUrl":"https://doi.org/10.1139/cjc-2023-0036","url":null,"abstract":"A comprehensive characterization of key mechanisms underlying signal transmission within the human brain remains an unsolved problem. The neuronal surface, composed principally of phosphatidylcholine (POPC), has a known ordering effect on water. This produces highly organized water layers (OWLs) at the neuron–water interface—the neurochemical implications of which are not currently understood. The human brain is 75% water by volume, with folds and grooves to maximize surface area, suggesting that characterization of neuronal OWLs may contribute to an understanding of neuronal signal transmission. Previous experimental work has measured enhanced conductivity of POPC OWLs relative to bulk water. The mechanism underlying this conductivity is still debated. Using quantum chemical methods on a POPC–water interface model system, we present data characterizing OWL conductance. Non-equilibrium Green's function calculation results demonstrate that there is negligible electron transfer-based conductivity through the OWL at biological temperatures. This is consistent with existing studies suggesting the Grotthuss mechanism as the most likely explanation for experimentally observed enhanced conductivity at the POPC–water interface. The broader implications of enhanced proton conductivity at the neuron–water interface are discussed.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"13 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80234951","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}
Giao N. Ngô, SunMin Park, Hailey M. Stack, J. Rourke, Jennifer A. Melanson, S. Westcott
This study reports the synthesis and characterization of a limited number of novel boron-containing and boron-omitted capsaicinoids, providing 12 unique substrates. We have previously reported boron-containing capsaicinoids that showed improved bioactivity compared to capsaicin itself but have yet to test a series of analogous boron-omitted substrates as a direct comparison. The boron-containing capsaicinoids bear a pinacolboronate ester (Bpin) group, which was incorporated using an iridium-catalyzed hydroboration reaction. We report that although nearly all compounds display moderate cytotoxic activity that bests that of capsaicin against human colon HCT116 cancer cells, the activity of our boron-omitted capsaicinoids surpasses that of the boron-containing analogues.
{"title":"A comparative study of boron-containing and boron-omitted capsaicinoids","authors":"Giao N. Ngô, SunMin Park, Hailey M. Stack, J. Rourke, Jennifer A. Melanson, S. Westcott","doi":"10.1139/cjc-2023-0043","DOIUrl":"https://doi.org/10.1139/cjc-2023-0043","url":null,"abstract":"This study reports the synthesis and characterization of a limited number of novel boron-containing and boron-omitted capsaicinoids, providing 12 unique substrates. We have previously reported boron-containing capsaicinoids that showed improved bioactivity compared to capsaicin itself but have yet to test a series of analogous boron-omitted substrates as a direct comparison. The boron-containing capsaicinoids bear a pinacolboronate ester (Bpin) group, which was incorporated using an iridium-catalyzed hydroboration reaction. We report that although nearly all compounds display moderate cytotoxic activity that bests that of capsaicin against human colon HCT116 cancer cells, the activity of our boron-omitted capsaicinoids surpasses that of the boron-containing analogues.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"2 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90566177","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}
Michael A. Land, Katrina D. Turrie, K. Robertson, J. Clyburne
1,3-dicholoro-1,3-bis(dialkylamino)propenium salts are prepared by condensing N,N,-dialkylamides with dichloromethylene dimethyliminium chloride ("Viehe’s Salt"). The products are versatile synthons and can be used to make a variety of ligand types. Here we report the syntheses of a number of new propenium salts and provide comprehensive characterization data for some which have already been described. Additionally, we have prepared a series of related 1,3-dihalo-1,3-bis(dimethylamino)propenium salts via halogen exchange reactions (F through I). Finally, all of the compounds described, including Viehe’s Salt and several hydrolysis products, have been characterized in the solid state using single-crystal X-ray diffraction. The symmetrical cations, [Me2NC(X)CHC(X)NMe2], were found to take one of two general structural forms. The first (X = H or F) is planar, presumably maximizing the delocalization within the backbone of the cation, while the second form is markedly twisted (X = Cl, Br or I). Calculations indicate that the latter develop increasingly positive regions of the electrostatic potential on the halide substituents, allowing cation/anion interactions via halogen bonding to dominate in the extended solids. The results of these studies illustrate the importance of the differing interionic interactions in a homologous series of small organic salts.
{"title":"Synthesis and solid state structures of 1,3-dihalo-1,3-bis(dialkylamino)propenium salts and related compounds","authors":"Michael A. Land, Katrina D. Turrie, K. Robertson, J. Clyburne","doi":"10.1139/cjc-2023-0042","DOIUrl":"https://doi.org/10.1139/cjc-2023-0042","url":null,"abstract":"1,3-dicholoro-1,3-bis(dialkylamino)propenium salts are prepared by condensing N,N,-dialkylamides with dichloromethylene dimethyliminium chloride (\"Viehe’s Salt\"). The products are versatile synthons and can be used to make a variety of ligand types. Here we report the syntheses of a number of new propenium salts and provide comprehensive characterization data for some which have already been described. Additionally, we have prepared a series of related 1,3-dihalo-1,3-bis(dimethylamino)propenium salts via halogen exchange reactions (F through I). Finally, all of the compounds described, including Viehe’s Salt and several hydrolysis products, have been characterized in the solid state using single-crystal X-ray diffraction. The symmetrical cations, [Me2NC(X)CHC(X)NMe2], were found to take one of two general structural forms. The first (X = H or F) is planar, presumably maximizing the delocalization within the backbone of the cation, while the second form is markedly twisted (X = Cl, Br or I). Calculations indicate that the latter develop increasingly positive regions of the electrostatic potential on the halide substituents, allowing cation/anion interactions via halogen bonding to dominate in the extended solids. The results of these studies illustrate the importance of the differing interionic interactions in a homologous series of small organic salts.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"6 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82009889","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 novel alkali flame ionization detector (AFID) is introduced and characterized for use as an air sensor (i.e. without chromatographic separation) for organo-nitrogen compounds. Using a planar channeled quartz design, a simple, lightweight architecture for the portable device is presented, which yields sensitive and selective response toward nitrogen-containing analytes. For instance, the AFID sensor offers a detection limit of 30 pg N/s and a selectivity for nitrogen response over carbon of nearly 2 orders of magnitude. Further, nitrogen response is linear over the 1000-fold range of concentrations investigated. Relative to a flame photometric detector (FPD) device also used in a sensor mode, the AFID is observed to provide 100 times greater S/N values for nitrogen analytes with a nitrogen to carbon selectivity that is about 15 times larger. When using the AFID and FPD sensors in tandem, it is found that the response ratio of the simultaneous signals generated by each, produces characteristic values that more clearly identify the presence or absence of nitrogen in unknown analytes. The AFID sensor was used to detect organo-nitrogen analytes in several samples, and results indicate that it could be a useful approach for portable air sensing of nitrogen compounds.
{"title":"CHARACTERISTICS OF A NOVEL ALKALI FLAME IONIZATION DETECTOR AS AN AIR SENSOR FOR VOLATILE ORGANO-NITROGEN COMPOUNDS","authors":"Cole M. Mogenson, K. Thurbide","doi":"10.1139/cjc-2023-0051","DOIUrl":"https://doi.org/10.1139/cjc-2023-0051","url":null,"abstract":"A novel alkali flame ionization detector (AFID) is introduced and characterized for use as an air sensor (i.e. without chromatographic separation) for organo-nitrogen compounds. Using a planar channeled quartz design, a simple, lightweight architecture for the portable device is presented, which yields sensitive and selective response toward nitrogen-containing analytes. For instance, the AFID sensor offers a detection limit of 30 pg N/s and a selectivity for nitrogen response over carbon of nearly 2 orders of magnitude. Further, nitrogen response is linear over the 1000-fold range of concentrations investigated. Relative to a flame photometric detector (FPD) device also used in a sensor mode, the AFID is observed to provide 100 times greater S/N values for nitrogen analytes with a nitrogen to carbon selectivity that is about 15 times larger. When using the AFID and FPD sensors in tandem, it is found that the response ratio of the simultaneous signals generated by each, produces characteristic values that more clearly identify the presence or absence of nitrogen in unknown analytes. The AFID sensor was used to detect organo-nitrogen analytes in several samples, and results indicate that it could be a useful approach for portable air sensing of nitrogen compounds.","PeriodicalId":9420,"journal":{"name":"Canadian Journal of Chemistry","volume":"168 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73942896","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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