Article
Chemistry, Multidisciplinary
Hsin-Wei Su, Junfeng Zhou, Seiyoung Yoon, Junpeng Wang
Summary: Chemically recyclable polymers offer a solution to the unsustainable use of plastics by enabling circular economy. The identification of appropriate monomers for polymerization and depolymerization is crucial in developing chemically recyclable polymers. The study shows that introducing an additional benzene ring favors polymerization and disfavors depolymerization, and the effect is predominantly entropic. The benzo-effect can be leveraged to facilitate the chemical recycling of polymers.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Physical
Jeffrey B. Schriber, Dominic A. Sirianni, Daniel G. A. Smith, Lori A. Burns, Doree Sitkoff, Daniel L. Cheney, C. David Sherrill
Summary: The Symmetry-adapted perturbation theory (SAPT) is a valuable tool for studying non-covalent interactions, but its computational cost can be reduced by replacing dispersion terms. The SAPT0-D3 method improves accuracy and efficiency, with the addition of functional group partitioning for analyzing binding interactions.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Yu-ichiro Izato, Akira Matsugi, Mitsuo Koshi, Atsumi Miyake
Summary: A simple heuristic model based on quantum mechanical calculations was developed to estimate the entropy of a solute molecule in an ideal solution. The model incorporated translational and rotational terms, as well as a configuration term calculated using a lattice model. The proposed model accurately reproduced the entropy values for solutes in non-aqueous solvents, but overestimated the entropies for aqueous molecules due to the lack of inclusion of hydrophobic effects.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Sam H. McCalmont, Ines C. M. Vaz, Hanne Oorts, Zheng Gong, Leila Moura, Margarida Costa Gomes
Summary: The solubility of gases in two phosphorus-containing ionic liquids was measured using an isochoric saturation method. The results showed that one ionic liquid had a higher capacity for absorbing olefins while the other had a higher capacity for absorbing paraffins. The study also concluded that solvation in both ionic liquids was dominated by entropy.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Sam H. McCalmont, Ines C. M. Vaz, Hanne Oorts, Zheng Gong, Leila Moura, Margarida Costa Gomes
Summary: This study measured the solubility of ethane, ethylene, propane, and propylene in two phosphorus-containing ionic liquids. The results showed that [P6,6,6,14][DiOP] had a higher absorption capacity for propane compared to [C4C1Im][DMP], and [C4C1Im][DMP] had a higher absorption capacity for olefins compared to [P6,6,6,14][DiOP]. The solvation in both ionic liquids was ruled by entropy, even if its contribution was unfavorable.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Sam H. McCalmont, Ines C. M. Vaz, Hanne Oorts, Zheng Gong, Leila Moura, Margarida Costa Gomes
Summary: The solubility of ethane, ethylene, propane, and propylene in two phosphorus-containing ionic liquids was investigated. It was found that [C4C1Im][DMP] could absorb 1 to 20 gas molecules per 1000 ion pairs, while [P6,6,6,14][DiOP] could absorb up to 169 propane molecules. The study also revealed that [C4C1Im][DMP] exhibited higher affinity for olefins, while [P6,6,6,14][DiOP] showed higher affinity for paraffins.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Physical
Kingo Ariyoshi, Kazuki Matsumoto
Summary: The investigation of insertion materials containing various cations has been prompted by the increased interest in post-lithium-ion batteries in recent years. However, the relationship between the electrochemical properties of cation insertion reactions and the inserted cations has not been evaluated. This study investigated the effect of inserted cations on the electrochemical properties of insertion reactions and found that the potential difference and rate capabilities of the reactions were influenced by the cation ionic radius and valency. Evaluating the relationship between the electrochemical properties and the cation valency and ionic radius provides important information for the development of post-LIBs.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Alexander P. Hawkins, Andrea Zachariou, Stewart F. Parker, Paul Collier, Nathan S. Barrow, Russell F. Howe, David Lennon
Summary: The cracking reactions of 1-octene over H-ZSM-5 zeolite were investigated, and it was found that it follows a dual-cycle hydrocarbon pool mechanism similar to methanol-to-hydrocarbons chemistry. Higher temperatures are required for full efficiency, while lower temperatures lead to deactivation and coke deposition. Inelastic neutron scattering was used to study coke composition, revealing two distinct deactivation mechanisms depending on reaction temperature. Steam treatment of the zeolite delayed catalyst activation and resulted in increased light olefin production, with slower deactivation compared to fresh zeolite.
APPLIED CATALYSIS A-GENERAL
(2023)
Article
Chemistry, Physical
Francois Mairesse, Benoit Champagne
Summary: The quantum treatment of electrons at the Kohn-Sham Density Functional Theory (DFT) level of approximation is used to optimize the structure of four organic and organo-metallic crystalline systems with nonlinear optical properties. The study addresses the lack of London-type interactions description in exchange-correlation functionals (XCFs) by employing the D* scheme, a variation of the D2 correction scaled for crystal solid state interactions. The performance and suitable scaling factors of the D* scheme are demonstrated for four representative XCFs.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Chemistry, Physical
W. J. M. J. Saumya R. Jayasundara, Georg Schreckenbach
JOURNAL OF PHYSICAL CHEMISTRY C
(2020)
Article
Chemistry, Physical
Elumalai Varathan, Yang Gao, Georg Schreckenbach
Summary: Relativistic density functional theory was used to study [AnO(2)(L)](0/-1) complexes with actinide metals (U, Np, Pu, Am) and a hexa-aza porphyrin analogue ligand. Shorter axial and longer equatorial bond lengths were observed with a decrease in oxidation state from An(VI) to An(V). The actinide to pyrrole nitrogen bonds played a dominant role in complex formation, with significant ligand-to-metal charge transfer. The formation energy trend in gas-phase and dichloromethane solution followed the order UO2L > PuO2L > NpO2 L > AmO2 L, with negative ΔG and ΔH values. Energy decomposition analysis revealed a predominance of electrostatic over covalent interactions in both pentavalent and hexavalent actinyl complexes, with decreasing covalent character from U to Am.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Inorganic & Nuclear
Yang Gao, Elumalai Varathan, Payal Grover, Georg Schreckenbach
Summary: The density functional theory study on 1,4,7,10-tetrazacyclodecane-1,4,7,10-tetraacetic acid (DOTA) aqueous complexes of Ac-III with H2O, dimethyl sulfoxide (DMSO), OH-, and F- as axial ligands shows that the formation of [Ac-III(DOTA)(OH)](2-) and [Ac-III(DOTA)(F)](2-) complexes is more favorable due to enhanced relative Gibbs free energies. The type and nature of the bond between Ac and the ligand donor atom is the main factor determining thermodynamic stability.
INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Durell S. Desmond, Diana Saltymakova, Odile Crabeck, Georg Schreckenbach, James D. Xidos, David G. Barber, Dustin Isleifson, Gary A. Stern
Summary: Decreases in Arctic sea ice extent have led to increased shipping and oil exploration, increasing the risk of accidental oil spills. Computational quantum chemistry was used to study the behavior of oil in sea ice and found that physical properties influence the relative movement of oil constituents.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Multidisciplinary
Najmeh Janatipour, Zabiollah Mahdavifar, Siamak Noorizadeh, Georg Schreckenbach
Summary: The electronic transport properties of a pristine C-6 chain and Si/B-substituted C-6 chains sandwiched between carbon nanotube electrodes were investigated. The study revealed that Si and B substitutions affect the I-V curve and result in multi negative differential resistance (NDR) and rectifying behavior. The asymmetric distribution of frontier molecular orbitals and their coupling with the electrodes were found to be responsible for the rectifying performance.
Article
Chemistry, Inorganic & Nuclear
Xiaobin Zhang, Sara L. Adelman, Brian T. Arko, Channa R. De Silva, Jing Su, Stosh A. Kozimor, Veronika Mocko, Jenifer C. Shafer, Benjamin W. Stein, Georg Schreckenbach, Enrique R. Batista, Ping Yang
Summary: Advancing the field of chemical separations is crucial for various scientific and technological areas. Research has shown that factors such as interactions, planarity, and preorganization of coordinating atoms play significant roles in the separation of americium ions.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Josef Tomecek, Cen Li, Georg Schreckenbach
Summary: In this study, the coordination chemistry of nine-coordinate Ac(III) complexes with various ligands was investigated using DFT. The analysis focused on the geometries, charges, reaction energies, and bonding interactions. The involvement of 5f orbitals on Ac was quantified, and strong correlations were found among Voronoi charges, Delta G reaction energies, and bond densities.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Parmissa Randhawa, K. Lexi Gower-Fry, Cailum M. K. Stienstra, Marianna Tosato, Shaohuang Chen, Yang Gao, Anthony W. McDonagh, Valerio Di Marco, Valery Radchenko, Georg Schreckenbach, Caterina F. Ramogida
Summary: This study reports a series of sulfur-rich chelators capable of stably coordinating Hg-197m/g to a tumor-targeting vector. The ability of these ligands to effectively coordinate Hg2+ was demonstrated through theoretical calculations and experimental studies, including NMR and mass spectrometry. Radiolabeling and in vitro stability assays further confirmed the potential application of these ligands. The development of stable ligands for Hg-197m/g reported in this study lays the foundation for their personalized use in in vivo imaging and therapy.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Inorganic & Nuclear
G. Abigail Jennifer, Yang Gao, Georg Schreckenbach, Elumalai Varathan
Summary: In this study, the complexation of actinyl moieties with the pyrrophen ligand was investigated using relativistic density functional theory. The results showed that the pentavalent actinyl complexes exhibited shorter bond lengths and higher bond orders compared to the hexavalent complexes. Charge analysis suggested that the complexation was facilitated through ligand-to-metal charge transfer. Moreover, the thermodynamic feasibility of complexation was confirmed and the role of orbital contributions in covalency was highlighted.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Yang Gao, Abigail G. Jennifer, Elumalai Varathan, Georg Schreckenbach
Summary: This study investigates the complexation of Am-III/Cm-III with DOTA in aqueous medium, revealing that OH--capped complexes are more likely to form due to their higher hydration Gibbs free energy. The electronic structure analysis shows that OH--capped complexes have stronger coordination ability than F-, and the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) compositions of Am complexes are contributed by 5f, while those of Cm complexes are derived from 5f and 6d. Furthermore, metal-exchange reactions demonstrate the competitive complexation of DOTA toward Am-III over Cm-III in the OH--capped system.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Inorganic & Nuclear
Ashutosh Parimi, Emmalee Mosher, Georg Schreckenbach
Summary: Due to the limited abundance of actinide elements, computational methods are important for investigating the periodic trends across the actinide series. By studying model systems of actinide compounds, the researchers captured the periodic trends and discovered that actinide elements exhibit different behavior before and after americium, with americium acting as a switch.
DALTON TRANSACTIONS
(2023)
Article
Chemistry, Multidisciplinary
Nicholas R. Andreychuk, Balamurugan Vidjayacoumar, Jeffrey S. Price, Sophie Kervazo, Craig A. Peeples, David J. H. Emslie, Valerie Vallet, Andre S. P. Gomes, Florent Real, Georg Schreckenbach, Paul W. Ayers, Ignacio Vargas-Baca, Hilary A. Jenkins, James F. Britten
Summary: The study suggests that arene solvents can suppress the ethylene polymerization activity in sterically open f-element complexes. Compounds in benzene and toluene showed lower polymerization activity, while compounds in fluorobenzene showed higher activity.
Article
Chemistry, Inorganic & Nuclear
Abigail G. Jennifer, Yang Gao, Georg Schreckenbach, Elumalai Varathan
Summary: In this work, the complexation properties of minor actinides in their dioxocation form with the dipyriamethyrin ligand were evaluated using density functional theory calculations. The results showed that the bond parameters indicated covalent character for the An=O-yl bonds and ionic character for the An-N bonds. The backdonation of charges from the metal to the ligand played a significant role in stabilizing the complexes, and the thermodynamic parameters suggested spontaneous complex formation. Energy decomposition analysis revealed that electrostatic contributions were the main interaction between the actinyl cation and the ligand, and there was an increase in orbital contributions due to backdonation of charges, which greatly stabilized the complex.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Physical
Behnaz Abyaz, Zabiollah Mahdavifar, Georg Schreckenbach, Yang Gao
Summary: Evolutionary searches combined with DFT calculations were used to determine the global minimum structures of beryllium clusters. The transition from 3D hollow cages to filled cage structures was observed at n=15. The Be-n clusters show strong absorption in the UV and visible regions, with Be-17 exhibiting promising photocatalytic activities.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Yang Gao, Payal Grover, Georg Schreckenbach
Summary: This study investigates the geometric and electronic structural properties of hydrated Ac-III cations, revealing that a complex of nine coordinated water molecules to the Ac-III cation is the most stable. It also highlights the importance of superatom states in actinide chemistry and the conversion mechanism between different coordination numbers.