Theoretical DFT study of Cannizzaro reaction mechanism: A mini perspective

Abstract

In regards to the Cannizzaro reaction and its peculiar mechanism, some researchers have presented a free radical mechanism for the Cannizzaro reaction, while others have found that it is feasible through an ionic mechanism, but the actual mechanism has not been finalized yet. The researchers have given the proof of both the mechanisms through their papers published. Actually, Cannizzaro reaction may occur through both mechanisms depending on both molecular structure and different conditions which are yet to be explained. Recently published papers describe that free radical mechanism occurs only in a heterogeneous medium, while an ionic mechanism occurs in a homogeneous medium. We revealed no explanation of the molecular structure-based reason, responsible for a radical or an ionic mechanism. The present paper reviews not only homogeneous/heterogeneous medium conditions but also molecular structure-based facts, which may be responsible for the Cannizzaro reaction to occur through the radical or ionic mechanism, and that may be acceptable to the scientific society. Besides, Density Functional Theory study using Gaussian software was also involved in the explanation of the molecular structure, responsible for one of the two mechanisms. Also, the present paper specifies all points related to future perspectives on which additional studies are required to understand the actual mechanism with a definite molecular structure in the different reaction media.

A quantum chemistry background of sickle cell anemia and gaps in antisickling drug development

“…According to data from the literature [44][45][46][47], a molecule with a higher frontier orbital gap (HOMO-LUMO energy gap) has low chemical reactivity and high kinetic stability because it is energetically unfavorable to add an electron to the high-lying LUMO in order to remove electrons from the low-lying HOMO. If Egap is higher, it becomes energetically unfavorable for an electron to jump from HOMO to LUMO [24,48], which is why conditions become very difficult for a molecule to take part in a chemical reaction. On the other hand, it becomes very easy for an electron to jump from HOMO to LUMO, if Egap is smaller; therefore, the conditions become very easy for a molecule to participate in a chemical reaction [24].…”

“…If Egap is higher, it becomes energetically unfavorable for an electron to jump from HOMO to LUMO [24,48], which is why conditions become very difficult for a molecule to take part in a chemical reaction. On the other hand, it becomes very easy for an electron to jump from HOMO to LUMO, if Egap is smaller; therefore, the conditions become very easy for a molecule to participate in a chemical reaction [24]. Based on these facts, Pro-Glu-Glu in HbA must be less reactive to fit into a hydrophobic pocket constituted by β88 leucine (Leu-beta88), β85phenylalanine (Phe-beta85), and β73 aspartic acid (Asp-beta73) residues on adjacent dHbS-M.…”

“…Of course, the simulation study has played an important role in the reaction mechanism [24], chiral separation [25][26][27][28], isolation of the most active gradient from the plant [29], and biological chemistry [30][31][32][33][34], but this is the first time the computational method has been applied to know the quantum background of the molecular disease. For the study at the quantum level, the pdb file of deoxygenated hemoglobin S (βGlu6 → Val) with PDB Code 2hbs [35] was obtained from the protein data bank.…”

A quantum chemistry background of sickle cell anemia and gaps in antisickling drug development

“…According to data from the literature [44][45][46][47], a molecule with a higher frontier orbital gap (HOMO-LUMO energy gap) has low chemical reactivity and high kinetic stability because it is energetically unfavorable to add an electron to the high-lying LUMO in order to remove electrons from the low-lying HOMO. If Egap is higher, it becomes energetically unfavorable for an electron to jump from HOMO to LUMO [24,48], which is why conditions become very difficult for a molecule to take part in a chemical reaction. On the other hand, it becomes very easy for an electron to jump from HOMO to LUMO, if Egap is smaller; therefore, the conditions become very easy for a molecule to participate in a chemical reaction [24].…”

“…If Egap is higher, it becomes energetically unfavorable for an electron to jump from HOMO to LUMO [24,48], which is why conditions become very difficult for a molecule to take part in a chemical reaction. On the other hand, it becomes very easy for an electron to jump from HOMO to LUMO, if Egap is smaller; therefore, the conditions become very easy for a molecule to participate in a chemical reaction [24]. Based on these facts, Pro-Glu-Glu in HbA must be less reactive to fit into a hydrophobic pocket constituted by β88 leucine (Leu-beta88), β85phenylalanine (Phe-beta85), and β73 aspartic acid (Asp-beta73) residues on adjacent dHbS-M.…”

“…Of course, the simulation study has played an important role in the reaction mechanism [24], chiral separation [25][26][27][28], isolation of the most active gradient from the plant [29], and biological chemistry [30][31][32][33][34], but this is the first time the computational method has been applied to know the quantum background of the molecular disease. For the study at the quantum level, the pdb file of deoxygenated hemoglobin S (βGlu6 → Val) with PDB Code 2hbs [35] was obtained from the protein data bank.…”

A theoretical density functional theory calculation-based analysis of conformers of p-xylene

“…The simulation study is very helpful in understanding the reaction mechanism [25][26][27][28], separation science [10,[29][30][31][32], and the existence of conformers [33]. The presented study involved three important steps.…”

The mystery of chemistry behind the mechanism of action of anti-HIV drugs: A docking approach at an atomic level

“…After that, the crystalline structures of reverse transcriptase [13] and CCR5 [14] with pdb codes 2rf2 and 6aky, respectively, were obtained from the protein data bank [https://www.rcsb.org/]. A computational study is very helpful not only in understanding the reaction mechanism [15] but also in drug development [16][17][18] and the mechanism of action in pharmacokinetics [19]. The currently presented docking study involved the following steps:…”

A quantum chemistry background of sickle cell anemia and gaps in antisickling drug development

“…According to data from the literature [44][45][46][47], a molecule with a higher frontier orbital gap (HOMO-LUMO energy gap) has low chemical reactivity and high kinetic stability because it is energetically unfavorable to add an electron to the high-lying LUMO in order to remove electrons from the low-lying HOMO. If Egap is higher, it becomes energetically unfavorable for an electron to jump from HOMO to LUMO [24,48], which is why conditions become very difficult for a molecule to take part in a chemical reaction. On the other hand, it becomes very easy for an electron to jump from HOMO to LUMO, if Egap is smaller; therefore, the conditions become very easy for a molecule to participate in a chemical reaction [24].…”

“…If Egap is higher, it becomes energetically unfavorable for an electron to jump from HOMO to LUMO [24,48], which is why conditions become very difficult for a molecule to take part in a chemical reaction. On the other hand, it becomes very easy for an electron to jump from HOMO to LUMO, if Egap is smaller; therefore, the conditions become very easy for a molecule to participate in a chemical reaction [24]. Based on these facts, Pro-Glu-Glu in HbA must be less reactive to fit into a hydrophobic pocket constituted by β88 leucine (Leu-beta88), β85phenylalanine (Phe-beta85), and β73 aspartic acid (Asp-beta73) residues on adjacent dHbS-M.…”

“…Of course, the simulation study has played an important role in the reaction mechanism [24], chiral separation [25][26][27][28], isolation of the most active gradient from the plant [29], and biological chemistry [30][31][32][33][34], but this is the first time the computational method has been applied to know the quantum background of the molecular disease. For the study at the quantum level, the pdb file of deoxygenated hemoglobin S (βGlu6 → Val) with PDB Code 2hbs [35] was obtained from the protein data bank.…”

A theoretical density functional theory calculation-based analysis of conformers of p-xylene

“…The simulation study is very helpful in understanding the reaction mechanism [25][26][27][28], separation science [10,[29][30][31][32], and the existence of conformers [33]. The presented study involved three important steps.…”

The mystery of chemistry behind the mechanism of action of anti-HIV drugs: A docking approach at an atomic level

“…After that, the crystalline structures of reverse transcriptase [13] and CCR5 [14] with pdb codes 2rf2 and 6aky, respectively, were obtained from the protein data bank [https://www.rcsb.org/]. A computational study is very helpful not only in understanding the reaction mechanism [15] but also in drug development [16][17][18] and the mechanism of action in pharmacokinetics [19]. The currently presented docking study involved the following steps:…”

A quantum chemistry background of sickle cell anemia and gaps in antisickling drug development

“…According to data from the literature [44][45][46][47], a molecule with a higher frontier orbital gap (HOMO-LUMO energy gap) has low chemical reactivity and high kinetic stability because it is energetically unfavorable to add an electron to the high-lying LUMO in order to remove electrons from the low-lying HOMO. If Egap is higher, it becomes energetically unfavorable for an electron to jump from HOMO to LUMO [24,48], which is why conditions become very difficult for a molecule to take part in a chemical reaction. On the other hand, it becomes very easy for an electron to jump from HOMO to LUMO, if Egap is smaller; therefore, the conditions become very easy for a molecule to participate in a chemical reaction [24].…”

“…If Egap is higher, it becomes energetically unfavorable for an electron to jump from HOMO to LUMO [24,48], which is why conditions become very difficult for a molecule to take part in a chemical reaction. On the other hand, it becomes very easy for an electron to jump from HOMO to LUMO, if Egap is smaller; therefore, the conditions become very easy for a molecule to participate in a chemical reaction [24]. Based on these facts, Pro-Glu-Glu in HbA must be less reactive to fit into a hydrophobic pocket constituted by β88 leucine (Leu-beta88), β85phenylalanine (Phe-beta85), and β73 aspartic acid (Asp-beta73) residues on adjacent dHbS-M.…”

“…Of course, the simulation study has played an important role in the reaction mechanism [24], chiral separation [25][26][27][28], isolation of the most active gradient from the plant [29], and biological chemistry [30][31][32][33][34], but this is the first time the computational method has been applied to know the quantum background of the molecular disease. For the study at the quantum level, the pdb file of deoxygenated hemoglobin S (βGlu6 → Val) with PDB Code 2hbs [35] was obtained from the protein data bank.…”

A theoretical density functional theory calculation-based analysis of conformers of p-xylene

“…The simulation study is very helpful in understanding the reaction mechanism [25][26][27][28], separation science [10,[29][30][31][32], and the existence of conformers [33]. The presented study involved three important steps.…”

The mystery of chemistry behind the mechanism of action of anti-HIV drugs: A docking approach at an atomic level

“…After that, the crystalline structures of reverse transcriptase [13] and CCR5 [14] with pdb codes 2rf2 and 6aky, respectively, were obtained from the protein data bank [https://www.rcsb.org/]. A computational study is very helpful not only in understanding the reaction mechanism [15] but also in drug development [16][17][18] and the mechanism of action in pharmacokinetics [19]. The currently presented docking study involved the following steps:…”