A resonance theory consistent with Mulliken-population concept

Ikeda, Atsushi; Nakao, Yoshiaki; Sato, Hirofumi; Sakaki, Shigeyoshi

doi:10.1016/j.cplett.2011.02.033

Cited by 14 publications

(11 citation statements)

References 48 publications

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“…Wiberg bond orders of O―H bonds were listed in Table . The bigger bond order, the bigger bond energy, the stronger valence bond . It could be known from Table that all the minimum bond orders were O―H bonds of carboxylic groups, so it was inferred that carboxyl lost a proton first to form [M − H] − .…”

Section: Resultsmentioning

confidence: 99%

Fragmentation characteristics of hydroxycinnamic acids in ESI‐MSⁿ by density functional theory

2017

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This work aims to analyze the electrospray ionization multistage mass spectrometry (ESI-MS ) fragmentation characteristics of hydroxycinnamic acids (HCAs) in negative ion mode. The geometric parameters, energies, natural bond orbitals and frontier orbitals of fragments were calculated by density functional theory (DFT) to investigate mass spectral fragmentation mechanisms. The results showed that proton transfer always occurred during fragmentation of HCAs; their quasi-molecular ions ([M - H] ) existed in more than one form and were mainly with the lowest energy. The fragmentation characteristics included the followings: (1) according to the different substitution position of phenolic hydroxyl group, the ring contraction reaction by CO elimination from benzene was in an increasingly difficult order: m-phenolic hydroxyl > p-phenolic hydroxyl > o-phenolic hydroxyl; and (2) ortho effect always occurred in o-dihydroxycinnamic acids (o-diHCAs), i.e. one phenolic hydroxyl group offered H , which combined with the other one to lose H O. In addition, there was a nucleophilic reaction during ring contraction in diHCAs that oxygen atom attacked the carbon atom binding with the other phenolic hydroxyl to lose CO . The fragmentation characteristics and mechanism of HCAs could be used for analysis and identification of such compounds quickly and effectively, and as reference for structural analogues by ESI-MS. Copyright © 2017 John Wiley & Sons, Ltd.

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Section: Resultsmentioning

confidence: 99%

Fragmentation characteristics of hydroxycinnamic acids in ESI‐MSⁿ by density functional theory

2017

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“…Therefore, Equation ( 27) is equivalent to the formula utilized for the analysis of MOs by Ikeda et al [25][26][27] In a similar manner, for the four-electron system, the weight is given by,…”

Section: Formulation Of the Weight Of Nonorthogonal Ao Determinantmentioning

confidence: 99%

“…24 Ikeda et al also tried to analyze MO wave functions in terms of resonance structure utilizing second quantized operators. [25][26][27] They focused on a second quantized formalism especially for nonorthogonal AOs. [28][29][30] In the present study, we followed the second quantized operator approach, and an alternative way for the analysis of MO wave function was derived.…”

Section: Introductionmentioning

confidence: 99%

An analysis of valence electronic structure from a viewpoint of resonance theory: Tautomerization of formamide and diazadiboretidine

et al. 2021

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The resonance theory is still very useful in understanding the valence electron structure.However, such a viewpoint is not usually obtained by general-purpose quantum chemical calculations, instead requires rather special treatment such as valence bond methods. In this study, we propose a method based on second quantization to analyze the results obtained by general-purpose quantum chemical calculations from the local point of view of electronic structure and analyze diazadiboretidine and the tautomerization of formamide. This method requires only the "PS"-matrix, consisting of the density matrix (P-matrix) and overlap matrix, and can be computed with a comparable load to that of Mulliken population analysis. A key feature of the method is that, unlike other methods proposed so far, it makes direct use of the results of general-purpose quantum chemical calculations.

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“…The present study only analyzed the influence of the Mulliken population on bond energy intensity. The Mulliken population was successfully applied to the S N 2 reaction with resonance theory by Ikeda et al [26]. When the Mulliken population of bonds is large, the covalent bond between atoms is strong; if it is small, there is minimal overlap of electronic clouds and bond covalency is weak.…”

Section: Mulliken Population Analysismentioning

confidence: 99%

Basic Characteristics of Hemimorphite and Its Transformation Mechanism with Na2CO3

et al. 2018

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The crystal of hemimorphite is a non-conductor. The Si-O bond in the crystal is strong, whereas the Zn-O bond is weak. These properties lead to the easy breakage of the Zn-O bond in the crushing process of hemimorphite. Thus, the interaction between minerals and polar water molecules is strong, and natural floatability of ores is poor. This study systematically investigated the characteristics of hemimorphite and its action mechanism with Na 2 CO 3. Results of SEM-EDS showed that the surface of hemimorphite dissolved after interacting with Na 2 CO 3 , and the contents of Si and O decreased, whereas Zn and C increased. XPS analysis showed that the carbonate group was detected. The interaction between CO 3 2− and hemimorphite was calculated using the first principles calculation based on density functional theory. The results indicate that an O atom in CO 3 2− interacted with Zn 2+ from the (100) plane of hemimorphite. The interaction between Zn and O atoms was not strong, and the Zn atoms were not completely displaced, which was proven by density of state analysis and the EDS and XPS results. The Mulliken population showed that the O-Zn bond was the atomic bonding of CO 3 2− with Zn 2+ and exhibited properties of ionic bonds. Thus, hemimorphite transformed to smithsonite-like mineral (ZnCO 3) when acting with CO 3 2− .

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A resonance theory consistent with Mulliken-population concept

Cited by 14 publications

References 48 publications

Fragmentation characteristics of hydroxycinnamic acids in ESI‐MSⁿ by density functional theory

Fragmentation characteristics of hydroxycinnamic acids in ESI‐MSⁿ by density functional theory

An analysis of valence electronic structure from a viewpoint of resonance theory: Tautomerization of formamide and diazadiboretidine

Basic Characteristics of Hemimorphite and Its Transformation Mechanism with Na2CO3

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A resonance theory consistent with Mulliken-population concept

Cited by 14 publications

References 48 publications

Fragmentation characteristics of hydroxycinnamic acids in ESI‐MSn by density functional theory

Fragmentation characteristics of hydroxycinnamic acids in ESI‐MSn by density functional theory

An analysis of valence electronic structure from a viewpoint of resonance theory: Tautomerization of formamide and diazadiboretidine

Basic Characteristics of Hemimorphite and Its Transformation Mechanism with Na2CO3

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Fragmentation characteristics of hydroxycinnamic acids in ESI‐MSⁿ by density functional theory

Fragmentation characteristics of hydroxycinnamic acids in ESI‐MSⁿ by density functional theory