Bond Dissociation Energy Values Research Articles

Reactivity of a heterobinuclear heme-peroxo-Cu complex with para-substituted catechols shows a pK a-dependent change in mechanism.

In biological systems, heme-copper oxidase (HCO) enzymes play a crucial role in the oxygen reduction reaction (ORR), where the pivotal O-O bond cleavage of the (heme)FeIII-peroxo-CuII intermediate is facilitated by active-site (peroxo core) hydrogen bonding followed by proton-coupled electron transfer (PCET) from a nearby (phenolic) tyrosine residue. A useful approach to comprehend the fundamental relationships among H-bonding/proton/H-atom donors and their abilities to induce O-O bond homolysis involves the investigation of synthetic, bioinspired model systems where the exogenous substrate properties (such as pK a and bond dissociation energy (BDE)) can be systematically altered. This report details the reactivity of a heme-peroxo-copper HCO model complex (LS-4DCHIm) toward a series of substituted catechol substrates that span a range of pK a and O-H bond BDE values, exhibiting different reaction mechanisms. Considering their interactions with the bridging peroxo ligand in LS-4DCHIm, the catechol substrates are importantly capable of one or two (i) H-bonds, (ii) proton transfers, and/or (iii) net H-atom transfers, thereby making them attractive, yet complex candidates for studying the redox chemistry of the metal-bound peroxide. A combination of spectroscopic studies and kinetic analysis implies that the suitable modulation of pK a and O-H bond BDE values of catechols result in either double proton transfer with the release of H2O2 or double PCET resulting in reductive O-O bond rupture. The distinguishing role of substrate properties in directing the mechanism and outcome of O2 protonation/reduction reactions is discussed in terms of designing O2-reduction catalysts based on biological inspiration.

Bond dissociation energy of O2 measured by fully state-to-state resolved threshold fragment yield spectra.

We have determined the bond dissociation energy of O2 by measuring fully state-to-state resolved threshold fragment yield spectra in the XUV energy region, O2X3Σg-,N″,J″→O(PJ3)+O(S1o3)/O(S2o5). Our results have yielded a bond dissociation energy value of 41 269.19 ± 0.10cm-1, which is consistent with previous measurements but exhibits a significantly lower uncertainty, approximately five times smaller. It is noteworthy that this study is the first to simultaneously achieve fine structure state resolution for the parent O2molecule and spin-orbit state resolution for the O(3PJ) fragments in the measurement of O2 bond dissociation energy. As a result, our findings have established a solid foundation for the obtained data.

Photocatalytic Generation of H2O2 Via a Hydrogen-Abstraction Pathway by Bi2.15WO6 under Visible Light.

Photocatalytic technology is a popular research area for converting solar energy into environmentally friendly chemicals and is considered the greenest approach for producing H2O2. However, the corresponding reactive oxygen species (ROS) and pathway involved in the photocatalytic generation of H2O2 by the Bi2.15WO6-glucose system are still not clear. Quenching experiments have established that neither •OH nor h+ contribute to the formation of H2O2, and show that the formed surface superoxo (≡Bi-OO•) and peroxo (≡Bi-OOH) species are the predominant ROS in H2O2 generation. In addition, various characterizations indicate the enhanced electron-transfer on the surface of Bi2.15WO6 with increasing contents of glucose via the ligand-to-metal charge transfer pathway, confirming H-transfer from glucose to ≡Bi-OO• or ≡Bi-OOH. The increased production of H2O2 with decreasing bond dissociation energy (BDEO-H) values of various phenolic compounds again supports the H-transfer mechanism from phenolic compounds to ≡Bi-OO• and then to ≡Bi-OOH. DFT calculations further reveal that on the Bi2.15WO6 surface, oxygen is sequentially reduced to ≡Bi-OO• and ≡Bi-OOH, while H-transfer from H2O or glucose to ≡Bi-OO• and ≡Bi-OOH, resulting in the production of H2O2. The lower energy barrier of H-transfer from adsorbed glucose (0.636 eV) than that from H2O (1.157 eV) indicates that H-transfer is more favorable from adsorbed glucose. This work gives new insight into the photocatalytic generation of H2O2 by Bi2.15WO6 in the presence of glucose/phenolic compounds via the H-abstraction pathway.

Electroluminescence efficiency and stability of near ultraviolet organic light-emitting diodes based on BCPO luminous materials

To date, in the traditional method of obtaining near-ultraviolet (NUV) light, mercury atoms, which can create a highly toxic heavy metal contaminant, have been used. Therefore, it is an important issue to obtain NUV light by using new environmentally friendly devices. In the last decade, the fabrication of near ultraviolet organic light-emitting diodes (NUV-OLEDs) has become a research hotspot in the field of organic electronics. However, when the electroluminescence wavelength is extended to shorter than 400 nm, higher requirements are put forward for the materials used for each functional layer in these devices. In this work, a wide bandgap small molecule material of BCPO is used as the luminescent layer. The electron-transporting and hole-transporting materials are determined based on the overlaps between absorption spectra of these materials and emission spectrum of BCPO. And NUV-OLEDs with electroluminescent peak wavelength at 384 nm are prepared. By using the optimal device structure, the maximum external quantum efficiency of the device reaches 2.98%, and the maximum radiance of the device reaches 38.2 mW/cm<sup>2</sup>. In the electroluminescence spectrum, NUV light with wavelengths below 400 nm accounts for 57% of the light emission. In addition, the device demonstrates good stability when biased at two different constant voltage modes. The multiple key factors which affect the stability of the device are analyzed in detail. Firstly, it is found that the high glass transition temperature (<i>T</i><sub>g</sub>) of hole-transporting material is very important for the long-time stability of this device. The poor device stability is closely related to the low <i>T</i><sub>g</sub> temperature of hole-transporting material. Secondly, due to the widespread use of PEDOT:PSS as hole injection material in OLEDs, the electron leakage from the hole-transpor layer into the PEDOT:PSS layer may cause significant damage to the conducting polymer. When bombarded with low energy electrons, bond breakage occurs on the surface of PEDOT:PSS, followed by the release of oxygen and sulfur, resulting in changes in conductivity and oxidation reactions with molecules of hole transport material. Thirdly, the photoelectrical stability of organic molecules is the most fundamental reason that restricts the device lifetime. The aging process of material or device is directly relevant to the bond dissociation energy (BDE) of organic molecule. Generally, the BDE value of organic molecule is not high enough. As a result, molecules are prone to chemical bond breakage during electrochemical or photochemical aging. In summary, highly stable NUV-OLEDs should be fabricated by using hole-transporting materials with high <i>T</i><sub>g</sub> temperature, sufficient electron-blocking capacity, and large BDE value.

Design of N-N ylide bond-based high energy density materials: a theoretical survey.

The generally encountered contradiction between large energy content and stability poses great difficulty in designing nitrogen-rich high-energy-density materials. Although N-N ylide bonds have been classified as the fourth type of homonuclear N-N bonds (besides >N-N<, -N[double bond, length as m-dash]N-, and N[triple bond, length as m-dash]N), accessible energetic molecules with N-N ylide bonds have rarely been explored. In this study, 225 molecules with six types of novel structures containing N-N ylide bonds were designed using density functional theory and CBS-QB3 methods. To guide future synthesis, the effects of substitution on the thermal stability, detonation velocity, and detonation pressure of the structures were evaluated under the premise that the N-N ylide skeleton remains stable. The calculations show that the bond dissociation energy values of the N-N ylide bonds of the designed 225 structures were in the range of 61.21-437.52 kJ mol-1, except for N-1NNH2. Many of the designed structures with N-N ylide bonds exhibit high detonation properties, which are superior to those of traditional energetic compounds. This study convincingly demonstrates the feasibility of the design strategy of introducing an N-N ylide bond to develop new types of energetic materials.

Robustness of Threshold Collision-Induced Dissociation Simulations for Bond Dissociation Energies.

The threshold collision-induced dissociation (T-CID) method is the workhorse for gas-phase bond dissociation energy (BDE) measurements. However, T-CID does not measure BDEs directly; instead, BDEs are obtained by fitting simulated data to the experimental data. We previously observed several large discrepancies between the computed and experimental BDEs. To analyze the reliability of the experimental values, we previously reported a study of the dissociation rate models in the simulation. Here, we report a study of the collision simulation part, specifically in the L-CID (ligand CID) program. We show that the BDE values are robust even to intentionally introduced mistakes in the simulations, varying in most cases by less than 3 kcal mol-1. The most significant exception is the collisional energy transfer (CET) simulation, which led to deviations larger than 10 kcal mol-1. However, we found that the BDEs obtained with explicitly simulated CET distributions deviated by only 3 kcal mol-1 from those simulated with the original model. Collectively, our results suggest that the T-CID-derived BDE values are robust and are likely to be accurate.

EVALUASI SENYAWA BIOAKTIF Nasturtium montanum Wall. SEBAGAI KANDIDAT AGEN ANTIPIRETIK TERHADAP RESEPTOR PROSTAGLANDIN SYNTASE 2 (PTGS2) SECARA IN SILICO [Evaluation of Bioactive Compounds of Nasturtium montanum Wall. as Antipyretic Agent Candidate Toward Prostaglandin Syntase 2 (PTGS2) Through in Silico

The inhibition of prostaglandin syntase 2 ( PTGS2 route is necessary in order to prevent an feverfever. Antipyretic drugs such as the Non steroids ( NSAIDs are fever medication which acts as non-selective inhibitor of PTGS2. NSAID overdose cases have led to herbal ingredients utilization as alternative remedies, such as the Nasturtium montanum leaves. This research aimed to observe the interaction of selected bioactive compounds within N. montanum with the PTGS2 target protein through molecular docking. In addition, this research used in silico approach conducted with molecular docking method trough several stages such as preparation of 3D ligand structure and protein, protein sterilization by PyMOL, docking compounds with PyRx and visualization of docking results via LigPlot+. Results obtained from this research shows the bond dissociation energy value of 1-O-sinapoyl-beta-D-glucose, kaempferol 3-O-sophoroside, patuletin 3-gentiobioside and quercetin 3-O-malonylglucoside substances are smaller compared to meclofenamic acid causing the four ligand tests more stable in their binding to PTGS2 receptor. Meclofenamic acid and 1-O-sinapoyl-beta-D-glucose both bind to PTGS2 receptor with the same amino acid residue as well as the same interaction. Whereas meclofenamic acid, kaempferol 3-O-sophoroside, patuletin 3-gentiobioside and quercetin 3-O-malonylglucoside bind to PTGS2 receptor with the same amino acid residue yet have different bond interaction.

Enhancement of metal‐binding affinity for Cu+/Cu2+ complexes by hydrogen bond network

AbstractUsing density functional theory, polyols were used as model ligands for Cu+/Cu2+ complexes to study the role of the hydrogen bond network on the metal binding affinity. In addition to the gas phase studies, the calculations were performed in 1‐decanol and DMSO solvents. The Cu2+ complexes were the most stable complexes with the highest bond dissociation energies (BDE). The presence of three H‐bonds in the first shell increased BDE values up to 17.99 and 57.07 kcal/mol for Cu+ and Cu2+ complexes in the gas phase, respectively, whereas the presence of another three H‐bonds in the second shell increased BDE values up to 7.27 and 24.35 kcal/mol for Cu+ and Cu2+ complexes in the gas phase, respectively. Therefore, this H‐bond network caused, for example, a more stable Cu+ complex with a formation constant of 1.4 × 1017 times. The natural bond orbital (NBO), atoms in molecules (AIM), and reduced density gradient (RDG) analyses showed that the intramolecular hydrogen bond network led to the enhancement of metal‐binding affinity.

Photoinduced One‐Electron Oxidation of Estrone Derivatives: A Combined Steady‐State and Time‐Resolved Spectroscopy Investigation

AbstractA detailed investigation of the photophysics and of the redox properties of a set of selected estrone carboxylate and sulfonate esters was carried out by means of steady‐state and time‐resolved spectroscopies. The observed dual fluorescence was assigned to an efficient intramolecular energy transfer from the aromatic moiety to the carbonyl group. On the other hand, the photoinduced monoelectronic oxidation of R−OX in the presence of persulphate anion is followed by mesolytic fragmentation of the so generated radical cation into the corresponding phenoxyl radical with rate constant values (kfrag) of 104–105 s−1, that depend on the X−O bond dissociation energy values.

Bond dissociation energies of the fifth‐row elements (InI): A quantum theoretical benchmark study

AbstractThe bond dissociation energies (BDE) of most main‐group elements have been accurately measured. However, the BDE values for heavy elements, particularly those from the fifth period (InI), are still missing or poorly validated. This study aims to identify the most accurate computational methods for calculating BDE values of compounds containing fifth‐row elements, including In, Sn, Sb, Te, and I, with a focus on readily accessible methods in software packages. The investigation involved a benchmark study using density functional theory (DFT), in addition to the 2nd order Møller–Plesset perturbation theory (MP2) and the coupled cluster with single, double, and perturbative triple excitations CCSD(T). The DFT functionals used in the study include APFD, B3LYP, B3LYP‐D3, B3P86, B97‐D3, BHandH, HSEH1PBE, M06‐2X, MN12‐SX, MN15‐L, and TPSSH. The functionals were carefully selected to cover some popular functionals as well as to cover all levels of the Jacob's ladder of DFT accuracy. The computed BDE values were compared with experimental values, and the results were filtered to remove any possible outliers. The statistical errors (MAPE, RMSE, and Pearson's) were then calculated and used to assess the performance of the methods.

Selective Nsp2 - and Csp2 - Photografting of Au-Surface by Aryldiazonium Salts and Arylazo Sulfonates.

Arylazo sulfonates (Ar-N=N-SO3 Na) have been found to undergo photografting on gold surface through both Au-Nsp2 - and Au-Csp2 - bond formation. The functionalized materials have been fully characterized by infrared reflection absorption spectroscopy (IRRAS), Raman, XPS, DFT calculations and UV-Vis absorption spectroscopy. These methods permit to evidence aromatic substituents (IRRAS), the Au-N=N signature (Raman and XPS spectroscopy), and the bond dissociation energy values of the two linkages (DFT calculation). The grafting proceeds through two competitive paths, namely a stepwise reaction involving an aryl radical (for the formation of the Au-Ar bonds) and a concerted reaction on the surface of gold (for Au-N=N-Ar bond formation). The occurrence of an aryl radical upon irradiation has been fully evidenced by EPR spectroscopy. Finally, E/Z photoisomerisation of the N=N bonds present on prepared few layer films has been observed by means of UV-Vis absorption spectroscopy.

Antioxidant potential of styrene pyrone polyphenols from Inonotus obliquus: A combined experimental, density functional theory (DFT) approach and molecular dynamic (MD) simulation

Polyphenols containing styrene pyranone skeleton are unique to porous fungi. Inonotus obliquus (IO) is a medicinal and edible porous fungus. Twelve phenolic compounds containing four styryl pyranone polyphenols from IO were isolated and identified in this work. The antioxidant ability of the isolates was characterized utilizing the ferric reducing antioxidant power (FRAP) assay and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) radical scavenging test. Styrylpyranone polyphenols, especially methylinoscavin B, could capture free radicals better than other phenolic compounds, and quantum chemical calculations also confirmed this evaluation. The density functional theory (DFT) calculation data showed that Styrylpyranone polyphenols, especially methylinoscavin B, have a lower energy gap, higher softness and higher electronic chemical potential than other phenolic compounds. The bond dissociation energy values of the bond in C7ʹ O–H of the methylinoscavin B molecule are less than those in C11 and C6ʹ O–H when reacting with ∙OOH (selected as a representative free radical). On the basis of calculations, hydrogen atom transfer (HAT) is supposed to be a preferred mechanism over single electron transfer (SET) when phenolic compounds react with free radicals. Moreover, after treatment with final concentrations of 0.5, 1, 2, 3, 4 and 5 μM phelligridin E (PHE), the activity of SOD1 increased by 70.15%, 11.36%, 145.45%, 172.73%, 205.05% and 275.23%, respectively. The molecular dynamics simulation (MD) study of PHE employed SOD1 (PDB ID: 6FN8). The MD results showed that the hydrogen bonds between ASP147 of SOD1 and PHE promote GLU223-ARG224 to form a stable C coil after combining with PHE. The formation of the C Coil enhanced the stability of the electrostatic loop (EL) of SOD1 and the rate of diffusion of the superoxide anion to the active site. Styrylpyrone polyphenols of Inonotus obliquus origin have the potential to be a source of vigorous free radical scavengers and antioxidant enzyme activators.

Extraction of scutched flax tow (SFT) in NHPI and PAG assisted H2O2 system in less water and low temperature environment

The extraction of flax fiber always consumed large amount of water and energy, and caused heavy Chemical oxygen demand (COD) discharge. Driven by the concept of green chemical and sustainable engineering, extracting flax fiber under less water environment and room temperature was necessary. This study conducted SFT degumming in nitroxide and H2O2 activating reagent aided alkali H2O2 (NAAH) system in less water environment under room temperature successfully. Results showed that N-Hydroxyphthalimide (NHPI) got much higher promoting effect in NAAH than that of 2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO) due to its high bond dissociation energy value. HAR could brought up the selectivity of the NAAH system, and the promoting effect increased in the order of TAED > MA >AGC >PAG. With the assistance of PAG and NHPI, the degumming could be conducted under less water environment under room temperature. Under the optimal reaction condition (0.25 g/L NHPI, 2.5 g/L PAG, bath ratio 1:10, 30 °C, 2 h), the cellulose, hemicellulose and lignin content reached 82.19%, 10.82% and 1.74% respectively; the density, tenacity, DP value and whiteness reached 14 dtex, 78 cN/dtex, 2100 and 52.0 respectively. Compared with fiber prepared in NaOH degumming and alkali H2O2 degumming system, the fiber prepared in NAAH system get better tensile property; consumed 50% and 50% less water; 6.45 × 106 kcal/h and 5.16 × 106 kcal/h less energy, and produced 9.52% and 73.5% lower COD discharge, respectively.

Antioxidative limonoids from Swietenia macrophylla fruits: Experimental, DFT (Density Functional Theory) approach, and docking study

Phytochemical investigation of the methanol extract of Swietenia macrophylla fruit first led to the isolation of four limonoids seneganolide (1), khayanone (2), khayanolide B (3), and 6-acetoxy-methyl angolensate (4). Compound 3 (IC50 3.18 µg/mL) was better than the positive control ascorbic acid (IC50 7.18 µg/mL) in an antioxidative assay against DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals. Compound 1 showed strong mosquito larvicidal activity against Aedes aegypti with LC50 values of 34.1–44.1 µg/mL and LC90 values of 57.3–65.1 µg/mL for 24 and 48-h exposures. Based on DFT (density functional theory)/B3LYP/6–311G(d,p) method, the SPL-ET (sequential proton loss-electron transfer) antioxidative mechanism is essential for compound 3 in polar solvents, while the HAT antioxidative route is appropriate in weak or non-polar mediums. Methine group at carbon C-6 of this compound exerted the lowest BDE (bond dissociation energy) values of 72.9–73.8 kcal/mol in both four studied mediums gas, benzene, methanol, and water. In the kinetic reactions with HOO•, CH3OO•, and •NO2 radicals, 6-CH also generated the lowest Gibbs free energy of activation ΔG# values of 14.5–24.2 kcal/mol and the highest rate constant K values of 6.068 × 101–1.75 × 106 L/mol.s. A molecular docking (MD) analysis of seneganolide with relevant Ae. aegypti protein targets revealed AChR (acetylcholine receptor), ACE2 (angiotensin converting enzyme 2), and aaNAT (arylalkylamine N-acetyltransferase) to be potential targets of this compound.

Bond dissociation energies of diatomic transition metal nitrides.

Resonant two-photon ionization (R2PI) spectroscopy has been used to measure the bond dissociation energies (BDEs) of the diatomic transition metal nitrides ScN, TiN, YN, MoN, RuN, RhN, HfN, OsN, and IrN. Of these, the BDEs of only TiN and HfN had been previously measured. Due to the many ways electrons can be distributed among the d orbitals, these molecules possess an extremely high density of electronic states near the ground separated atom limit. Spin-orbit and nonadiabatic interactions couple these states quite effectively, so that the molecules readily find a path to dissociation when excited above the ground separated atom limit. The result is a sharp drop in ion signal in the R2PI spectrum when the molecule is excited above this limit, allowing the BDE to be readily measured. Using this method, the values D0(ScN) = 3.905(29) eV, D0(TiN) = 5.000(19) eV, D0(YN) = 4.125(24) eV, D0(MoN) = 5.220(4) eV, D0(RuN) = 4.905(3) eV, D0(RhN) = 3.659(32) eV, D0(HfN) = 5.374(4) eV, D0(OsN) = 5.732(3) eV, and D0(IrN) = 5.115(4) eV are obtained. To support the experimental findings, ab initio coupled-cluster calculations extrapolated to the complete basis set limit (CBS) were performed. With a semiempirical correction for spin-orbit effects, these coupled-cluster single double triple-CBS calculations give a mean absolute deviation from the experimental BDE values of 0.20eV. A discussion of the periodic trends, summaries of previous work, and comparisons to isoelectronic species is also provided.

Inorganic Acids, Fluoridated Ethanol’s, and Some Fluoridated Saturated Hydrocarbons’ Stability and Bond Dissociation Energy Values.

The energetics of chemical processes can be assessed using bond dissociation energy values. The objective of this work is to calculate the hydrogen-halogen (H-X) and carbon- fluorine (C-F) bond dissociation energy values for some energetic materials including fluorinated ethanols, some fluorinated saturated hydrocarbons, and some inorganic acids. Bond dissociation energy values for 40 different compounds are reported in this work. All calculated bond dissociation energy is reported for standard conditions, 1 atm pressure and 298 K temperature. Bond dissociation energy values are listed in tables 1,2 and 3.

Electrostatic interactions, binding energies and structures of the [formula omitted] complexes

The binding energies and structures of the Be cations with H2 molecules are studied theoretically at the level of the MP2 method. In this study the aug-cc-pVTZ basis set is used to describe the electronic configuration of these atoms in the complex. The structures of these complexes are determined for Be+2·H21-4 complexes. The sequential bond energies of the Be2+·(H2)1−4 complexes are also examined. The variations in the electrostatic interaction energies could be the cause of the observed trend in sequential bond dissociation energy values.

Theoretical and Experimental Investigation of Autoxidation Propensity of Selected Drugs in Solution State.

The C-H bond dissociation energy (BDE) of drug molecules is often used to estimate their relative propensities to undergo autoxidation. BDE calculations based on electronic structures provide a convenient means to estimate the risk for a given compound to degrade via autoxidation. This study aimed to verify the utility of calculated C-H BDEs of a range of drug molecules in predicting their autoxidation propensities, in the solution state. For the autoxidation study, 2,2'-azobis (2-methylpropionitrile) was employed as the solution state stressor, and the experimental reaction rate constants were determined employing ultraperformance liquid chromatographic (UPLC) methods. Reaction rates in the solution state were compared to the calculated C-H BDE values of the respective compounds. The results indicated a poor correlation for compounds in the solution state, and their relative stabilities could not be explained with C-H BDE. On the other hand, a favorable relationship was observed between the relative extent of ionization and the autoxidation rates of the selected compounds. In the solution state, factors such as the type and extent of drug ionization, degree and type of solvation have been shown to contribute to differences in reactivity. By applying the computational method involving the effect of H-atom abstraction and potential ionization sites in the molecule, the calculated C-H BDE should relate better to the experimental autoxidation rates.

Evaluation of Free Radical Quenching Ability of Quinoline Acids through in vitro and Theoretical Studies

Drugs based antioxidants are commonly suggested as targets while designing new medicines. All sorts of pharmaceutical drug development benefit from the extremely desirable quinoline moiety with antioxidant. In this work, the scavenging behaviour of four quinoline derivatives (Q1-Q4) towards DPPH, H2O2, ABTS and superoxide activity were investigated. According to the in vitro inhibition concentration (IC50), quinoline derivative Q1 showed high antioxidant potential. Additionally, the theoretical DFT gas phase calculations of HOMO-LUMO, MEP, NPA and NBO are used to study the conjugating systems in radicals and showed that the N-H site acts more favourable than the O-H site for the radical attack. The calculated bond dissociation energy (BDE) values demonstrated that compound Q1 follows the HAT mechanism and while the calculated ionization potential (IP) and proton dissociation energy (PDE) values showed that Q4 follows the SET-PT route. The results of these two mechanisms demonstrated that radical quenching activity occurs at the N-H and O-H sites. The spin density demonstrates that both radicals are delocalized uniformly across the molecule.

Thermodynamic Evaluation on Alkoxyamines of TEMPO Derivatives, Stable Alkoxyamines or Potential Radical Donors?

AbstractIn this work, the bond dissociation energy (BDE) values, including BDE(O−X) and BDE(N−O), for 129 alkoxyamines (XRT) of TEMPO derivatives were predicted, and the evaluations on stabilities of alkoxyamines, reactivities of alkoxyamines as radical donors and reactivity of TEMPO as various radical scavenger are well compared and discussed based on the predicted BDE values from the view of thermodynamic driving forces. Without a doubt, the wide and valuable BDE values are helpful for chemists better understand the thermodynamic properties and kinetic behaviors of alkoxyamines and TEMPO in chemical reactions and drug metabolism in vivo and promoting the rapid development and application of novel alkoxyamines.