The Experts below are selected from a list of 603 Experts worldwide ranked by ideXlab platform

C. Kalalian - One of the best experts on this subject based on the ideXlab platform.

  • temperature dependent kinetic study of the gas phase reaction of ozone with 1 penten 3 ol cis 2 penten 1 ol and trans 3 hexen 1 ol experimental and theoretical data
    Atmospheric Environment, 2020
    Co-Authors: C. Kalalian, E Roth, H.j. Singh, A Chakir
    Abstract:

    Abstract C5 and C6 unsaturated alcohols are a family of biogenic volatile organic compounds (BVOC) emitted in the atmosphere from vegetation in response to their injuries. In this work, we report the first temperature dependent rate constants for the reaction of three unsaturated alcohols: 1-penten-3-ol (1P3OL), cis-2-penten-1-ol (c-2P1OL) and tran-3-hexen-1-ol (t-3H1OL) with ozone in a pyrex reactor coupled to a FTIR spectrometer and to a GC/MS at four different temperatures (273, 298, 313 and 333 K), at atmospheric pressure, using a relative method. The Arrhenius expressions obtained are (cm3 molecule−1 s−1): The studied reactions were also explored theoretically using computational methods based on quantum chemical theory characterizing the intermediates, transition states and the subsequent formation of reaction products. The rate constants were calculated at room temperature employing a modified transition-state theory (MTST). Both results obtained experimentally and theoretically, were discussed in terms of structure-reactivity relationships and temperature dependence. Tropospheric lifetimes of the investigated species with respect to ozone are calculated. The obtained results showed that these species are not persistent towards ozonolysis process.

  • Product investigation of the gas phase ozonolysis of 1-penten-3-ol, cis-2-penten-1-ol and trans-3-hexen-1-ol
    Atmospheric Environment, 2020
    Co-Authors: C. Kalalian, E Roth, Gisèle El Dib, H.j. Singh, P.k. Rao, Abdelkhaleq Chakir
    Abstract:

    It is well known that the ozonolysis of organic compounds leads to the formation of oxygenated products, which can increase the oxidizing ability of the atmosphere. In this work, the products of the gas phase reactions of ozone with three unsaturated alcohols 1-penten-3-ol (1P3OL), cis-2-penten-1-ol (c-2P1OL) and trans-3-hexen-1-ol (t-3H1OL) were investigated. The products formation yields were determined at 298 K and 760 Torr, in dry condition, in a 63 L pyrex reactor. The analysis of the products was performed in situ using Fourrier transform infrared (FTIR) spectroscopy (ie technique) and solid phase microextraction sampling in conjunction with gas chromatography coupled to mass spectrometry (SPME/GC-MS) (ie technique). The average yields of primary products were (in %) formaldehyde (62 +/- 12) and 2-hydroxybutanal (46 +/- 10) for the reaction of O-3 with 1-penten-3-ol; glycolaldehyde (56 +/- 14) and propanal (40 +/- 10) for the reaction of O-3 with cis-2-penten-1-ol; propanal (63 +/- 8) and 3-hydroxypropanal (43 +/- 10) for the reaction of O-3 with trans-3-hexen-1-ol. As for secondary products, their average yields were (in %) propanal (12 +/- 4) and acetaldehyde (10 +/- 4) for the ozonolysis of 1-penten-3-ol; acetaldehyde (13 +/- 5), 2-hydroxypropanal (10 +/- 2) and methylglyoxal (3 +/- 1) for the ozonolysis of cis-2-penten-1-ol, acetaldehyde (30 +/- 4), glycolaldehyde (16 +/- 4) and methylglyoxal (8 +/- 3) for the ozonolysis of trans-3-hexen-1-ol. The obtained yields were compared to the values available in literature. Based on the results obtained in this study, plausible reaction mechanisms of the ozonolysis of these unsaturated alcohols have been proposed.

Sara R Jaeger - One of the best experts on this subject based on the ideXlab platform.

  • Genetic Variation in the Odorant Receptor OR2J3 Is Associated with the Ability to Detect the “Grassy” Smelling Odor, Cis-3-Hexen-1-Ol
    Chemical senses, 2012
    Co-Authors: Jeremy F Mcrae, Sara R Jaeger, Joel D. Mainland, Kaylin A. Adipietro, Hiroaki Matsunami, Richard D. Newcomb
    Abstract:

    The ability to detect many odors varies among individuals; however, the contribution of genotype to this variation has been assessed for relatively few compounds. We have identified a genetic basis for the ability to detect the flavor compound Cis-3-Hexen-1-Ol. This compound is typically described as “green grassy” or the smell of “cut grass,” with variation in the ability to detect it linked to single nucleotide polymorphisms (SNPs) in a region on human chromosome 6 containing 25 odorant receptor genes. We have sequenced the coding regions of all 25 receptors across an ethnically mixed population of 52 individuals and identified 147 sequence variants. We tested these for association with Cis-3-Hexen-1-Ol detection thresholds and found 3 strongly associated SNPs, including one found in a functional odorant receptor (rs28757581 in OR2J3). In vitro assays of 13 odorant receptors from the region identified 3 receptors that could respond to Cis-3-Hexen-1-Ol, including OR2J3. This gene contained 5 predicted haplotypes across the 52 individuals. We tested all 5 haplotypes in vitro and several amino acid substitutions on their own, such as rs28757581 (T113A). Two amino acid substitutions, T113A and R226Q, impaired the ability of OR2J3 to respond to Cis-3-Hexen-1-Ol, and together these two substitutions effectively abolished the response to the compound. The haplotype of OR2J3 containing both T113A and R226Q explains 26.4% of the variation in Cis-3-Hexen-1-Ol detection in our study cohort. Further research is required to examine whether OR2J3 haplotypes explain variation in perceived flavor experience and the consumption of foods containing Cis-3-Hexen-1-Ol.

  • investigation of the impact of sensitivity to cis 3 hexen 1 ol green grassy on food acceptability and selection
    Food Quality and Preference, 2012
    Co-Authors: Sara R Jaeger, Benedicte Pineau, Jeremy F Mcrae, Christina M Bava, Michelle K Beresford, Sok L Chheang, Kelly R Atkinson, Lauren G Axten, Mei Peng, Amy G Paisley
    Abstract:

    Abstract The impact of taste acuity on consumer acceptability and food selection responses has been studied for some time, particularly in the case of bitterness. Less attention has been given to the impact of odor acuity on such responses. To begin to bridge this gap, this investigation is focused on Cis-3-Hexen-1-Ol (green/grassy) and the questions explored were: (1) does varying sensitivity to the odor of Cis-3-Hexen-1-Ol impact hedonic responses to food stimuli that have been spiked with this odorant? and (2) does varying sensitivity to the odor of Cis-3-Hexen-1-Ol impact self-reported food selection? The results from three studies involving 400+ consumers are reported. They are: (1) confirm that in the case of Cis-3-Hexen-1-Ol, odor acuity has a small but systematic impact on acceptability and (2) suggest that this result could extend to food selection. Hedonic responses to hummus, tomato juice and Japanese green tea spiked with two different concentrations of Cis-3-Hexen-1-Ol were negative (relative to the unspiked samples) and these response patterns were similar in consumers of Caucasian and Japanese ancestry. Compared to participants classified as ‘sensitive’ to the odor of Cis-3-Hexen-1-Ol, the negative responses to the spiked foods were less strong among ‘insensitive’ participants. Similar response patterns emerged when Caucasian consumers hedonically assessed the odor of gold kiwifruit essence spiked with Cis-3-Hexen-1-Ol: increasing spike concentration was perceived negatively, but the magnitude of the negative responses was less among participants classified as ‘insensitive’ to the odor of Cis-3-Hexen-1-Ol. Preferences for the odor of gold kiwifruit essence spiked with Cis-3-Hexen-1-Ol varied among ‘sensitive’ and ‘insensitive’ participants, and revealed a preference among ‘insensitive’ participants for intermediate spike concentrations relative to high and low spike concentrations. The impact on food selection was studied using a 142-item 24 h self-completion food recall questionnaire, where participants indicated whether or not they had consumed each of the focal foods/beverages. Participants provided data for at least seven 24 h recall periods (18 periods on average) and the proportion of days where items were consumed was compared. Amid considerable individual variation in dietary patterns, a tendency towards participants classified as ‘sensitive’ to the odor of Cis-3-Hexen-1-Ol to more frequently consume mild cheese, salad greens and cucumber was uncovered. This result should be considered tentative and more as a suggestion for future targeted research into the impact of sensitivity to the odor of Cis-3-Hexen-1-Ol on food selection.

  • Investigation of the impact of sensitivity to Cis-3-Hexen-1-Ol (green/grassy) on food acceptability and selection
    Food Quality and Preference, 2012
    Co-Authors: Sara R Jaeger, Benedicte Pineau, Jeremy F Mcrae, Christina M Bava, Michelle K Beresford, Sok L Chheang, Kelly R Atkinson, Lauren G Axten, Mei Peng, Amy G Paisley
    Abstract:

    Abstract The impact of taste acuity on consumer acceptability and food selection responses has been studied for some time, particularly in the case of bitterness. Less attention has been given to the impact of odor acuity on such responses. To begin to bridge this gap, this investigation is focused on Cis-3-Hexen-1-Ol (green/grassy) and the questions explored were: (1) does varying sensitivity to the odor of Cis-3-Hexen-1-Ol impact hedonic responses to food stimuli that have been spiked with this odorant? and (2) does varying sensitivity to the odor of Cis-3-Hexen-1-Ol impact self-reported food selection? The results from three studies involving 400+ consumers are reported. They are: (1) confirm that in the case of Cis-3-Hexen-1-Ol, odor acuity has a small but systematic impact on acceptability and (2) suggest that this result could extend to food selection. Hedonic responses to hummus, tomato juice and Japanese green tea spiked with two different concentrations of Cis-3-Hexen-1-Ol were negative (relative to the unspiked samples) and these response patterns were similar in consumers of Caucasian and Japanese ancestry. Compared to participants classified as ‘sensitive’ to the odor of Cis-3-Hexen-1-Ol, the negative responses to the spiked foods were less strong among ‘insensitive’ participants. Similar response patterns emerged when Caucasian consumers hedonically assessed the odor of gold kiwifruit essence spiked with Cis-3-Hexen-1-Ol: increasing spike concentration was perceived negatively, but the magnitude of the negative responses was less among participants classified as ‘insensitive’ to the odor of Cis-3-Hexen-1-Ol. Preferences for the odor of gold kiwifruit essence spiked with Cis-3-Hexen-1-Ol varied among ‘sensitive’ and ‘insensitive’ participants, and revealed a preference among ‘insensitive’ participants for intermediate spike concentrations relative to high and low spike concentrations. The impact on food selection was studied using a 142-item 24 h self-completion food recall questionnaire, where participants indicated whether or not they had consumed each of the focal foods/beverages. Participants provided data for at least seven 24 h recall periods (18 periods on average) and the proportion of days where items were consumed was compared. Amid considerable individual variation in dietary patterns, a tendency towards participants classified as ‘sensitive’ to the odor of Cis-3-Hexen-1-Ol to more frequently consume mild cheese, salad greens and cucumber was uncovered. This result should be considered tentative and more as a suggestion for future targeted research into the impact of sensitivity to the odor of Cis-3-Hexen-1-Ol on food selection.

  • Sensory perception and facial reactions of two odors : the case of Cis-3-Hexen-1-Ol and beta-ionone.
    2012
    Co-Authors: Karin Wendin, Kelly R Atkinsson, Andrea Manu, Sara R Jaeger
    Abstract:

    Sensory perception and facial reactions of two odors : the case of Cis-3-Hexen-1-Ol and beta-ionone.

  • A preliminary investigation into a genetic basis for Cis-3-Hexen-1-Ol odour perception: A genome-wide association approach
    Food Quality and Preference, 2010
    Co-Authors: Sara R Jaeger, Jeremy F Mcrae, Yael Salzman, Liam Williams, Richard D. Newcomb
    Abstract:

    Odour perception is controlled by environmental and genetic influences. Most people can discriminate over 10,000 different odours, but the molecular basis of this ability is poorly understood. Little is known about which odorant receptors (ORs) detect what odour compounds, and additional research is required to gain knowledge of why detection thresholds for some odorants vary 1000-fold, or more, across people. The primary purpose of this paper is to describe a research strategy for investigating the genetic basis of human odour perception. Background information on human olfaction, human genetics and the associated research approaches is presented. This is followed by a case study on Cis-3-Hexen-1-Ol, a compound which contributes to the ‘green leaf’ odour (and flavour) in fruit, vegetables and wine. Odour detection threshold data for 48 participants were obtained using the rating R-index methodology. The ability to perceive Cis-3-Hexen-1-Ol odour was tested for association with genetic variability on a genome-wide scale by microarray probe genotyping. A group of significant SNPs on chromosome 6 around the SNP rs9295791 was identified and these localise with a cluster of OR genes which could potentially be involved in perception of Cis-3-Hexen-1-Ol. Further steps required to identify genes and alleles that encode the different ability to perceive Cis-3-Hexen-1-Ol are outlined.

Abdelkhaleq Chakir - One of the best experts on this subject based on the ideXlab platform.

  • Product investigation of the gas phase ozonolysis of 1-penten-3-ol, cis-2-penten-1-ol and trans-3-hexen-1-ol
    Atmospheric Environment, 2020
    Co-Authors: C. Kalalian, E Roth, Gisèle El Dib, H.j. Singh, P.k. Rao, Abdelkhaleq Chakir
    Abstract:

    It is well known that the ozonolysis of organic compounds leads to the formation of oxygenated products, which can increase the oxidizing ability of the atmosphere. In this work, the products of the gas phase reactions of ozone with three unsaturated alcohols 1-penten-3-ol (1P3OL), cis-2-penten-1-ol (c-2P1OL) and trans-3-hexen-1-ol (t-3H1OL) were investigated. The products formation yields were determined at 298 K and 760 Torr, in dry condition, in a 63 L pyrex reactor. The analysis of the products was performed in situ using Fourrier transform infrared (FTIR) spectroscopy (ie technique) and solid phase microextraction sampling in conjunction with gas chromatography coupled to mass spectrometry (SPME/GC-MS) (ie technique). The average yields of primary products were (in %) formaldehyde (62 +/- 12) and 2-hydroxybutanal (46 +/- 10) for the reaction of O-3 with 1-penten-3-ol; glycolaldehyde (56 +/- 14) and propanal (40 +/- 10) for the reaction of O-3 with cis-2-penten-1-ol; propanal (63 +/- 8) and 3-hydroxypropanal (43 +/- 10) for the reaction of O-3 with trans-3-hexen-1-ol. As for secondary products, their average yields were (in %) propanal (12 +/- 4) and acetaldehyde (10 +/- 4) for the ozonolysis of 1-penten-3-ol; acetaldehyde (13 +/- 5), 2-hydroxypropanal (10 +/- 2) and methylglyoxal (3 +/- 1) for the ozonolysis of cis-2-penten-1-ol, acetaldehyde (30 +/- 4), glycolaldehyde (16 +/- 4) and methylglyoxal (8 +/- 3) for the ozonolysis of trans-3-hexen-1-ol. The obtained yields were compared to the values available in literature. Based on the results obtained in this study, plausible reaction mechanisms of the ozonolysis of these unsaturated alcohols have been proposed.

Jeremy F Mcrae - One of the best experts on this subject based on the ideXlab platform.

  • Genetic Variation in the Odorant Receptor OR2J3 Is Associated with the Ability to Detect the “Grassy” Smelling Odor, Cis-3-Hexen-1-Ol
    Chemical senses, 2012
    Co-Authors: Jeremy F Mcrae, Sara R Jaeger, Joel D. Mainland, Kaylin A. Adipietro, Hiroaki Matsunami, Richard D. Newcomb
    Abstract:

    The ability to detect many odors varies among individuals; however, the contribution of genotype to this variation has been assessed for relatively few compounds. We have identified a genetic basis for the ability to detect the flavor compound Cis-3-Hexen-1-Ol. This compound is typically described as “green grassy” or the smell of “cut grass,” with variation in the ability to detect it linked to single nucleotide polymorphisms (SNPs) in a region on human chromosome 6 containing 25 odorant receptor genes. We have sequenced the coding regions of all 25 receptors across an ethnically mixed population of 52 individuals and identified 147 sequence variants. We tested these for association with Cis-3-Hexen-1-Ol detection thresholds and found 3 strongly associated SNPs, including one found in a functional odorant receptor (rs28757581 in OR2J3). In vitro assays of 13 odorant receptors from the region identified 3 receptors that could respond to Cis-3-Hexen-1-Ol, including OR2J3. This gene contained 5 predicted haplotypes across the 52 individuals. We tested all 5 haplotypes in vitro and several amino acid substitutions on their own, such as rs28757581 (T113A). Two amino acid substitutions, T113A and R226Q, impaired the ability of OR2J3 to respond to Cis-3-Hexen-1-Ol, and together these two substitutions effectively abolished the response to the compound. The haplotype of OR2J3 containing both T113A and R226Q explains 26.4% of the variation in Cis-3-Hexen-1-Ol detection in our study cohort. Further research is required to examine whether OR2J3 haplotypes explain variation in perceived flavor experience and the consumption of foods containing Cis-3-Hexen-1-Ol.

  • investigation of the impact of sensitivity to cis 3 hexen 1 ol green grassy on food acceptability and selection
    Food Quality and Preference, 2012
    Co-Authors: Sara R Jaeger, Benedicte Pineau, Jeremy F Mcrae, Christina M Bava, Michelle K Beresford, Sok L Chheang, Kelly R Atkinson, Lauren G Axten, Mei Peng, Amy G Paisley
    Abstract:

    Abstract The impact of taste acuity on consumer acceptability and food selection responses has been studied for some time, particularly in the case of bitterness. Less attention has been given to the impact of odor acuity on such responses. To begin to bridge this gap, this investigation is focused on Cis-3-Hexen-1-Ol (green/grassy) and the questions explored were: (1) does varying sensitivity to the odor of Cis-3-Hexen-1-Ol impact hedonic responses to food stimuli that have been spiked with this odorant? and (2) does varying sensitivity to the odor of Cis-3-Hexen-1-Ol impact self-reported food selection? The results from three studies involving 400+ consumers are reported. They are: (1) confirm that in the case of Cis-3-Hexen-1-Ol, odor acuity has a small but systematic impact on acceptability and (2) suggest that this result could extend to food selection. Hedonic responses to hummus, tomato juice and Japanese green tea spiked with two different concentrations of Cis-3-Hexen-1-Ol were negative (relative to the unspiked samples) and these response patterns were similar in consumers of Caucasian and Japanese ancestry. Compared to participants classified as ‘sensitive’ to the odor of Cis-3-Hexen-1-Ol, the negative responses to the spiked foods were less strong among ‘insensitive’ participants. Similar response patterns emerged when Caucasian consumers hedonically assessed the odor of gold kiwifruit essence spiked with Cis-3-Hexen-1-Ol: increasing spike concentration was perceived negatively, but the magnitude of the negative responses was less among participants classified as ‘insensitive’ to the odor of Cis-3-Hexen-1-Ol. Preferences for the odor of gold kiwifruit essence spiked with Cis-3-Hexen-1-Ol varied among ‘sensitive’ and ‘insensitive’ participants, and revealed a preference among ‘insensitive’ participants for intermediate spike concentrations relative to high and low spike concentrations. The impact on food selection was studied using a 142-item 24 h self-completion food recall questionnaire, where participants indicated whether or not they had consumed each of the focal foods/beverages. Participants provided data for at least seven 24 h recall periods (18 periods on average) and the proportion of days where items were consumed was compared. Amid considerable individual variation in dietary patterns, a tendency towards participants classified as ‘sensitive’ to the odor of Cis-3-Hexen-1-Ol to more frequently consume mild cheese, salad greens and cucumber was uncovered. This result should be considered tentative and more as a suggestion for future targeted research into the impact of sensitivity to the odor of Cis-3-Hexen-1-Ol on food selection.

  • Investigation of the impact of sensitivity to Cis-3-Hexen-1-Ol (green/grassy) on food acceptability and selection
    Food Quality and Preference, 2012
    Co-Authors: Sara R Jaeger, Benedicte Pineau, Jeremy F Mcrae, Christina M Bava, Michelle K Beresford, Sok L Chheang, Kelly R Atkinson, Lauren G Axten, Mei Peng, Amy G Paisley
    Abstract:

    Abstract The impact of taste acuity on consumer acceptability and food selection responses has been studied for some time, particularly in the case of bitterness. Less attention has been given to the impact of odor acuity on such responses. To begin to bridge this gap, this investigation is focused on Cis-3-Hexen-1-Ol (green/grassy) and the questions explored were: (1) does varying sensitivity to the odor of Cis-3-Hexen-1-Ol impact hedonic responses to food stimuli that have been spiked with this odorant? and (2) does varying sensitivity to the odor of Cis-3-Hexen-1-Ol impact self-reported food selection? The results from three studies involving 400+ consumers are reported. They are: (1) confirm that in the case of Cis-3-Hexen-1-Ol, odor acuity has a small but systematic impact on acceptability and (2) suggest that this result could extend to food selection. Hedonic responses to hummus, tomato juice and Japanese green tea spiked with two different concentrations of Cis-3-Hexen-1-Ol were negative (relative to the unspiked samples) and these response patterns were similar in consumers of Caucasian and Japanese ancestry. Compared to participants classified as ‘sensitive’ to the odor of Cis-3-Hexen-1-Ol, the negative responses to the spiked foods were less strong among ‘insensitive’ participants. Similar response patterns emerged when Caucasian consumers hedonically assessed the odor of gold kiwifruit essence spiked with Cis-3-Hexen-1-Ol: increasing spike concentration was perceived negatively, but the magnitude of the negative responses was less among participants classified as ‘insensitive’ to the odor of Cis-3-Hexen-1-Ol. Preferences for the odor of gold kiwifruit essence spiked with Cis-3-Hexen-1-Ol varied among ‘sensitive’ and ‘insensitive’ participants, and revealed a preference among ‘insensitive’ participants for intermediate spike concentrations relative to high and low spike concentrations. The impact on food selection was studied using a 142-item 24 h self-completion food recall questionnaire, where participants indicated whether or not they had consumed each of the focal foods/beverages. Participants provided data for at least seven 24 h recall periods (18 periods on average) and the proportion of days where items were consumed was compared. Amid considerable individual variation in dietary patterns, a tendency towards participants classified as ‘sensitive’ to the odor of Cis-3-Hexen-1-Ol to more frequently consume mild cheese, salad greens and cucumber was uncovered. This result should be considered tentative and more as a suggestion for future targeted research into the impact of sensitivity to the odor of Cis-3-Hexen-1-Ol on food selection.

  • A preliminary investigation into a genetic basis for Cis-3-Hexen-1-Ol odour perception: A genome-wide association approach
    Food Quality and Preference, 2010
    Co-Authors: Sara R Jaeger, Jeremy F Mcrae, Yael Salzman, Liam Williams, Richard D. Newcomb
    Abstract:

    Odour perception is controlled by environmental and genetic influences. Most people can discriminate over 10,000 different odours, but the molecular basis of this ability is poorly understood. Little is known about which odorant receptors (ORs) detect what odour compounds, and additional research is required to gain knowledge of why detection thresholds for some odorants vary 1000-fold, or more, across people. The primary purpose of this paper is to describe a research strategy for investigating the genetic basis of human odour perception. Background information on human olfaction, human genetics and the associated research approaches is presented. This is followed by a case study on Cis-3-Hexen-1-Ol, a compound which contributes to the ‘green leaf’ odour (and flavour) in fruit, vegetables and wine. Odour detection threshold data for 48 participants were obtained using the rating R-index methodology. The ability to perceive Cis-3-Hexen-1-Ol odour was tested for association with genetic variability on a genome-wide scale by microarray probe genotyping. A group of significant SNPs on chromosome 6 around the SNP rs9295791 was identified and these localise with a cluster of OR genes which could potentially be involved in perception of Cis-3-Hexen-1-Ol. Further steps required to identify genes and alleles that encode the different ability to perceive Cis-3-Hexen-1-Ol are outlined.

E Roth - One of the best experts on this subject based on the ideXlab platform.

  • temperature dependent kinetic study of the gas phase reaction of ozone with 1 penten 3 ol cis 2 penten 1 ol and trans 3 hexen 1 ol experimental and theoretical data
    Atmospheric Environment, 2020
    Co-Authors: C. Kalalian, E Roth, H.j. Singh, A Chakir
    Abstract:

    Abstract C5 and C6 unsaturated alcohols are a family of biogenic volatile organic compounds (BVOC) emitted in the atmosphere from vegetation in response to their injuries. In this work, we report the first temperature dependent rate constants for the reaction of three unsaturated alcohols: 1-penten-3-ol (1P3OL), cis-2-penten-1-ol (c-2P1OL) and tran-3-hexen-1-ol (t-3H1OL) with ozone in a pyrex reactor coupled to a FTIR spectrometer and to a GC/MS at four different temperatures (273, 298, 313 and 333 K), at atmospheric pressure, using a relative method. The Arrhenius expressions obtained are (cm3 molecule−1 s−1): The studied reactions were also explored theoretically using computational methods based on quantum chemical theory characterizing the intermediates, transition states and the subsequent formation of reaction products. The rate constants were calculated at room temperature employing a modified transition-state theory (MTST). Both results obtained experimentally and theoretically, were discussed in terms of structure-reactivity relationships and temperature dependence. Tropospheric lifetimes of the investigated species with respect to ozone are calculated. The obtained results showed that these species are not persistent towards ozonolysis process.

  • Product investigation of the gas phase ozonolysis of 1-penten-3-ol, cis-2-penten-1-ol and trans-3-hexen-1-ol
    Atmospheric Environment, 2020
    Co-Authors: C. Kalalian, E Roth, Gisèle El Dib, H.j. Singh, P.k. Rao, Abdelkhaleq Chakir
    Abstract:

    It is well known that the ozonolysis of organic compounds leads to the formation of oxygenated products, which can increase the oxidizing ability of the atmosphere. In this work, the products of the gas phase reactions of ozone with three unsaturated alcohols 1-penten-3-ol (1P3OL), cis-2-penten-1-ol (c-2P1OL) and trans-3-hexen-1-ol (t-3H1OL) were investigated. The products formation yields were determined at 298 K and 760 Torr, in dry condition, in a 63 L pyrex reactor. The analysis of the products was performed in situ using Fourrier transform infrared (FTIR) spectroscopy (ie technique) and solid phase microextraction sampling in conjunction with gas chromatography coupled to mass spectrometry (SPME/GC-MS) (ie technique). The average yields of primary products were (in %) formaldehyde (62 +/- 12) and 2-hydroxybutanal (46 +/- 10) for the reaction of O-3 with 1-penten-3-ol; glycolaldehyde (56 +/- 14) and propanal (40 +/- 10) for the reaction of O-3 with cis-2-penten-1-ol; propanal (63 +/- 8) and 3-hydroxypropanal (43 +/- 10) for the reaction of O-3 with trans-3-hexen-1-ol. As for secondary products, their average yields were (in %) propanal (12 +/- 4) and acetaldehyde (10 +/- 4) for the ozonolysis of 1-penten-3-ol; acetaldehyde (13 +/- 5), 2-hydroxypropanal (10 +/- 2) and methylglyoxal (3 +/- 1) for the ozonolysis of cis-2-penten-1-ol, acetaldehyde (30 +/- 4), glycolaldehyde (16 +/- 4) and methylglyoxal (8 +/- 3) for the ozonolysis of trans-3-hexen-1-ol. The obtained yields were compared to the values available in literature. Based on the results obtained in this study, plausible reaction mechanisms of the ozonolysis of these unsaturated alcohols have been proposed.