A5026280150- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Radioactive element chemistry and processing
- Nuclear Materials and Properties
- Lanthanide and Transition Metal Complexes
- Advanced Chemical Physics Studies
- Organometallic Complex Synthesis and Catalysis
- Crystallography and molecular interactions
- Spectroscopy and Quantum Chemical Studies
- Catalysis and Oxidation Reactions
- Magnetism in coordination complexes
- Diamond and Carbon-based Materials Research
- Radioactive contamination and transfer
- Coordination Chemistry and Organometallics
- High-pressure geophysics and materials
- Synthesis and characterization of novel inorganic/organometallic compounds
- Rare-earth and actinide compounds
- Semiconductor materials and devices
- Nuclear reactor physics and engineering
- Chemical Synthesis and Characterization
- Quantum and electron transport phenomena
- Electrochemical Analysis and Applications
- Porphyrin and Phthalocyanine Chemistry
- Chemical Thermodynamics and Molecular Structure
- Quantum Computing Algorithms and Architecture
Lancaster University
2015-2024
Lancaster City Council
2016-2019
Faraday Technology (United States)
2019
Los Alamos National Laboratory
2018
Lawrence Berkeley National Laboratory
2018
University of Manchester
2018
University of Washington
2018
University College London
2007-2016
Transnational Press London
2014
London Centre for Nanotechnology
2007-2008
Evaluating the nature of chemical bonding for actinide elements represents one most important and long-standing problems in science. We directly address this challenge contribute a Cl K-edge X-ray absorption spectroscopy relativistic density functional theory study that quantitatively evaluates An–Cl covalency AnCl62– (AnIV = Th, U, Np, Pu). The results showed significant mixing between 3p- AnIV 5f- 6d-orbitals (t1u*/t2u* t2g*/eg*), with showing more pronounced covalent than 5f-orbitals....
Abstract Across the periodic table trans -influence operates, whereby tightly bonded ligands selectively lengthen mutually metal–ligand bonds. Conversely, in high oxidation state actinide complexes inverse- where normally cis strongly donating instead reside and actually reinforce each other. However, because is restricted to high-valent actinyls a few uranium(V/VI) complexes, it has had limited scope an area with unifying rules. Here we report tetravalent cerium, uranium thorium bis...
The electronic structure of f-element compounds is complex due to a combination relativistic effects, strong electron correlation and weak crystal field environments. However, quantitative understanding bonding in these becoming increasingly technologically relevant. Recently, interpretations based on analyses the physically observable density have gained popularity and, this Feature Article, utility such density-based approaches demonstrated. Application Bader's Quantum Theory Atoms...
Against expectations the covalency in a cerium(<sc>iv</sc>)–carbon multiple bond interaction is essentially as covalent uranium(<sc>iv</sc>) analogue.
The magnetic coupling of flexible metal phthalocyanine (MPc) thin films can be modified depending on the polymorphic form adopted by crystals. A simple annealing procedure switch couplings from antiferromagnetic to ferromagnetic (MnPc) or paramagnetic (CuPc), opening up avenues for spintronic applications. Density functional and perturbation theories rationalize these trends attribute mechanism indirect exchange.
CASSCF calculated wavefunctions are presented for three f-element metallocenes, MCOT2 (M = Ce, Th, Pu; COT η(8)-C8H8). The configurational admixture of these systems is investigated and, where the ThCOT2 ground state well-defined as a monodeterminantal Th(IV) state, cerocene found to be strong multiconfigurational and bear similarities that plutonocene. Associated electronic densities studied using QTAIM topological analysis compared CASSCF-derived aromatic benzene dianion. This provides...
Multiconfigurational studies and topological analysis demonstrate 5f-orbital contributions to covalency in actinocenes.
The molecular structures of a series uranyl (UO22+) complexes in which the uranium center is equatorially coordinated by first-row species are calculated at density functional theory level and binding energies deduced. resulting electronic investigated using variety density-based analysis techniques order to quantify degree covalency equatorial bonds. It shown that consideration properties both one-electron electron-pair densities required understand rationalize variation axial bonding...
Spin−orbit free CASPT2 wave functions and energies are presented for the ground 31 excited states of three f element sandwich molecules; thorocene (ThCOT2), protactinocene (PaCOT2), cerocene (CeCOT2). Ground-state metal-ring centroid distances optimized at this level show excellent agreement with experiment. The effects spin−orbit coupling included found to be negligible ThCOT2 CeCOT2, which comparison electronic excitation is made experimental data. For PaCOT2, alter significantly nature...
The interactions between water and the actinide oxides UO2 PuO2 are important both fundamentally when considering long-term storage of spent nuclear fuel. However, experimental studies in this area severely limited by intense radioactivity plutonium, hence, we have recently begun to investigate these computationally. In paper, report results plane-wave density functional theory calculations interaction with {111}, {110}, {100} surfaces PuO2, using a Hubbard-corrected potential (PBE + U)...
Emission spectroscopy has been used for the first time in a spectroscopic study of family uranium(IV) halide complexes non-aqueous media. The room temperature electronic absorption spectra simple coordination compounds [Li(THF)4][UX5(THF)] (X = Cl, Br, I), [Et4N]2[UCl6] and UCl4 THF have recorded all transitions assigned with aid comprehensive computational using CASSCF CASPT2 techniques. Excitation into band f-d LMCT character followed by energy transfer 5f-orbital manifold accounts...
The discovery of solvates (crystal structures where the solvent is incorporated into lattice) dates back to dawn chemistry. phenomenon ubiquitous, with important applications ranging from development pharmaceuticals potential capture CO2 atmosphere. Despite this interest, we still do not fully understand why some molecules form solvates. We have employed molecular simulations using simple models solute and whose interaction parameters could be modulated at will access a universe that...
The substoichiometric {111}, {110}, and {100} surfaces of UO2 PuO2 are studied computationally using two distinct yet related approaches based on density functional theory (DFT): the periodic electrostatic embedded cluster method Hubbard-corrected boundary condition DFT. first second layer oxygen vacancy formation energies geometries presented discussed; found to be substantially larger for versus PuO2, a result that traced more positive An(IV)/An(III) reduction potential Pu hence relative...
The geometrical and electronic structures of Ln[(H2O)9]3+ [Ln(BTP)3]3+, where Ln = Ce-Lu, have been evaluated at the density functional level theory using three related exchange-correlation (xc-)functionals. BHLYP xc-functional was found to be most accurate, this, along with B3LYP functional, used as basis for topological studies electron via quantum atoms in molecules (QTAIM). This analysis revealed that, both sets complexes, bonding almost identical across series dominated by ionic...
The optical absorption spectra of magnesium oxide nanoparticles, along with the atomic centres responsible for absorption, are studied using time-dependent density functional theory.
Abstract Improving our comprehension of diverse CO 2 activation pathways is vital importance for the widespread future utilization this abundant greenhouse gas. by uranium(III) complexes now relatively well understood, with oxo/carbonate formation predominating as readily reduced to CO, but isolated thorium(III) unprecedented. We show that complex, [Th(Cp′′) 3 ] ( 1 , Cp′′={C 5 H (SiMe ) ‐1,3}), reacts give mixed oxalate‐carboxylate thorium(IV) complex [{Th(Cp′′) [κ ‐O C{C ‐3,3′‐(SiMe }]}...
Syntheses of rare examples U(V) methyl and U(IV) ylide complexes are reported. Reaction the previously reported imido complex [(C5Me5)2U(py)(═NMes)] (py = pyridine, Mes 2,4,6-Me3C6H2) with CuI forms [(C5Me5)2U(I)(═NMes)]. iodo MgMe2 produces [(C5Me5)2U(CH3)(═NMes)]. The was reacted CH2PPh3, surprisingly forming [(C5Me5)2U(CH2PPh3)(═NMes)], a ylide. This is formed from disproportionation transient carbene, leading to U(VI) bis(imido) complex, [(C5Me5)2U(═NMes)2]. These were characterized...
We report a comparison of the molecular and electronic structures dithio- diselenophosphinate, (E2PR2)1– (E = S, Se; R iPr, tBu), with thorium(IV) uranium(IV) complexes. For thorium dithiophosphinate complexes, reaction ThCl4(DME)2 4 equiv KS2PR2 (R tBu) produced homoleptic Th(S2PiPr2)4 (1S-Th-iPr) Th(S2PtBu2)4 (2S-Th-tBu). The diselenophosphinate complexes were synthesized in similar manner using KSe2PR2 to produce Th(Se2PiPr2)4 (1Se-Th-iPr) Th(Se2PtBu2)4 (2Se-Th-tBu). U(S2PiPr2)4,...
The electronic structure of a series uranium and cerium hexachlorides in variety oxidation states was evaluated at both the correlated wavefunction density functional (DFT) levels theory. Following recent experimental observations covalency tetravalent hexachlorides, bonding character studied using topological integrated analysis based on quantum theory atoms molecules (QTAIM). This revealed that M–Cl strongly dependent state, with greater found higher state complexes. Comparison...
Lappert's original Th(<sc>iii</sc>) complex, [Th{C<sub>5</sub>H<sub>3</sub>(SiMe<sub>3</sub>)<sub>2</sub>-1,3}<sub>3</sub>], reduces white phosphorus to give a cyclo-P<sub>4</sub> dianion, which exhibits an unprecedented μ–η<sup>1</sup>:η<sup>1</sup>-binding mode in the dinuclear Th(<sc>iv</sc>) product.
Solubility is a fundamental property of widespread significance. Despite its importance, efficient and accurate prediction from first principles remains major challenge. Here we propose novel method to predict the solubility molecules using density states (DOS) approach classical molecular simulation. The offers potential route for large (including drug-like) over range temperatures pressures, all modest number simulations. was employed sodium chloride in water at ambient conditions,...
Spin-orbit free and spin-orbit coupled CASPT2 wave functions energies are presented for the ground low-lying excited states of four actinide element sandwich molecules; thorocene (ThCOT(2)), uranocene (UCOT(2)), plutonocene (PuCOT(2)), curocene (CmCOT(2)). coupling is found to make little difference equilibrium geometry but has a significant effect on energy spectrum all systems considered here other than thorocene. In cases, however, dominant contribution their counterparts. Following work...