Thermodynamic properties of phosphorus-containing compounds were investigated using high-level ab initio computations. An extended set of contemporary density functional theory (DFT) procedures was assessed for their ability to accurately predict bond dissociation energies of a set of phosphoranyl radicals. The results of meta- and double-hybrids as well as more recent methods, in particular M05, M05-2X, M06, and M06-2X, were compared with benchmark G3(MP2)-RAD values. Standard heats of formation, entropies, and heat capacities of a set of ten organophosphorus compounds were determined and the low-cost BMK functional was found to provide results consistent with available experimental data. In addition, bond dissociation enthalpies (BDEs) were computed using the BMK, M05-2X, and SCS-ROMP2 procedure. The three methods give the same stability trend. The BDEs of the phosphorus(III) molecules were found to be lower than their phosphorus(V) counterparts. Overall, the following ordering is found: BDE(P-OPh) < BDE(P-CH(3)) < BDE(P-Ph) < BDE(P-OCH(3)).
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J Mol Graph Model
January 2025
Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry of the Russian Academy of Sciences, 1 Academician Semenov Avenue, 142432, Chernogolovka, Russian Federation.
Gas phase bond dissociation energies (BDE) O-H/N-H in hydroquinone (HQ), 4-aminophenol (AP), 1,4-phenylenediamine (PDA), 4-hydroxydiphenylamine (HDPA), N,N'-diphenyl-1,4-phenylenediamine (DPPDA) as well as in their phenoxyl/aminyl radicals have been determined using a combined technique of quantum chemical calculation. The technique included a series of DFT (PBE1PBE, TPSSTPSS, M06-2X), ab initio (DLPNO-CCSD(T)) methods with valence 3ξ-basis sets, composite methods of Gaussian family (G4) and Weizmann theory with ab initio Brueckner Doubles (W1BD), as well as reference reactions of different levels of structural similarity. W1BD method was used in combination with isodesmic reactions for BDE estimation (kJ∙mol) of compounds with the only aromatic fragment: BDE = 352.
View Article and Find Full Text PDFMater Horiz
January 2025
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China.
Polymer photo-oxidation aging is a significant issue in plastics engineering, leading to reduced performance, shorter lifespan, and additional pollution. Anti-aging agents, including antioxidants and ultraviolet (UV)-shielding agents, are used to ameliorate the above problems. However, multi-component agents involve complex synthesis, mixed processing, and environmental concerns.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
School of Materials, Sun Yat-Sen University, Shenzhen 518107, China; State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275, China. Electronic address:
J Phys Chem A
January 2025
Department of Chemistry and Biochemistry, The University of Alabama, Tuscaloosa, Alabama 35487-0336, United States.
The bonding and spectroscopic properties of LaX and AcX (X = O and F) diatomic molecules were studied by high-level ab initio CCSD(T) and SO-CASPT2 electronic structure calculations. Bond dissociation energies (BDEs) were calculated at the Feller-Peterson-Dixon (FPD) level. Potential energy curves and spectroscopic constants for the lowest-lying spin-orbit Ω states were obtained at the SO-CASPT2/aQ-DK level.
View Article and Find Full Text PDFJ Chem Inf Model
January 2025
Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
In the field of computational chemistry, predicting bond dissociation energies (BDEs) presents well-known challenges, particularly due to the multireference character of reactive systems. Many chemical reactions involve configurations where single-reference methods fall short, as the electronic structure can significantly change during bond breaking. As generating training data for partially broken bonds is a challenging task, even state-of-the-art reactive machine learning interatomic potentials (MLIPs) often fail to predict reliable BDEs and smooth dissociation curves.
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