Thomas Malcomson

Cardiff University | CU · School of Biosciences

Using BS-DFT (broken-symmetry density functional theory), the electronic and magnetic properties of the S3YZ• state of photosystem II were investigated and compared to those of the S3 state. While the O5 oxo–O6 hydroxo species presents little difference between the two states, a previously identified [O5O6]3– exhibits reduced stabilization of the O...

A series of novel lanthanum amido complexes, supported by ligands designed around the salan framework (salan = N,N′-bis(o-hydroxy, m-di-tert-butylbenzyl)-1,2-diaminoethane) were synthesized and fully characterized in the solid and solution states. The ligands incorporate benzyl or 2-pyridyl substituents at each tertiary amine center. The complexes...

Despite increase in demand, capacity for the recycling of rare earth elements remains limited, partly due to the inefficiencies with processes currently utilised in the separation of lanthanides. This study highlights the potential use of expanded porphyrinoids in lanthanide separation through selective binding, dependent on the tailored pore size...

[MFe3S4] cubanes have for some time been of interest for their ability to mimic the electronic and geometric structure of the active site of nitrogenase, the enzyme responsible for fixing N2 to NH3. Nitrogenase naturally occurs in three forms, with the major difference being that the metal ion present in the cofactor active site is either molybdenu...

We compare the stabilities and bonding nature of [Eu/Am(BTPhen)2(NO3)]2+ complexes to those previously reported for [Eu/Am(BTP)3]3+, and investigate whether more accurately reflecting the reaction conditions of the separation process by considering [Eu/Am(NO3)3(H2O)x] (x = 3, 4) complexes instead of aquo complexes increases the selectivity of the s...

Regioselective stepwise phenylation of 4,7-diarylbenzo[c][1,2,5]thiadiazole fluorophores has been achieved through a facile one-pot, three-step synthetic strategy involving sequential borylation, hydroxydechlorination and Suzuki-Miyaura cross-coupling reactions. Crucial to the selectivity was the use of BCl3 to regioselectively install a boronic ac...

Time-resolved photoelectron imaging and supporting ab initio quantum chemistry calculations were used to investigate non-adiabatic excess energy redistribution dynamics operating in the saturated thioethers diethylsulfide, tetrahydrothiophene and thietane. In all cases, 200 nm excitation leads to molecular fragmentation on an ultrafast (<100 fs) ti...

Suitability of single-reference density functional theory (DFT) methods for the calculation of redox potentials of copper-containing macrocycle complexes was confirmed by the use of T 1 diagnostics along with a verification of negligible spin contamination or wave function instability. When examining the effect of improvement in the cc-pVnZ basis s...

Time dependent density functional theory (TDDFT) calculations have been performed on a series of symmetry-preserving excited states of the uranyl dication, UO22+. The simulated excited state electronic structures are compared to that of the ground state at both ground and excited state-optimised geometries. For the first time, the Quantum Theory of...

In this work, the dithiolene complex iron(III) bis‐maleonitriledithiolene [Fe(mnt) 2 ] is characterised and evaluated as a homogeneous CO 2 reduction catalyst. Electrochemically the Fe(mnt) 2 is reduced twice to the trianionic Fe(mnt) 2 3‐ state, which is correspondingly found to be active towards CO 2 . Interestingly, the first reduction event app...

With the prevalence of fluorescence spectroscopy in biological systems, and the benefits of two-photon absorption techniques, presented here is an assessment of the two-photon accessibility of modern fluorescent nucleobase analogues utilising quadratic response DFT. Due to the complex environment experienced by these nucleobases, the two-photon spe...

Electron donor-acceptor (D-A) systems based on the benzo[c][1,2,5]thiadiazole (BTZ) motif have been extensively researched for use in photovoltaics or as fluorescent sensors. However, their use as potential visible-light organophotocatalysts has...

Control of self-sorting regimes is achieved through adjustment of steric interactions in self-assembled coordination cages. The self-assembly regime of dynamic mixtures of heteroleptic cages is followed by HPLC to show...

In continuing to examine the interaction of actinide-ligand bonds with soft donor ligands, a comparative investigation with phosphorus and arsenic was conducted. A reaction of (C5Me5)2AnMe2, An = Th, U, with 2 equiv of H2AsMes, Mes = 2,4,6-Me3C6H2, forms the primary bis(arsenido) complexes, (C5Me5)2An[As(H)Mes]2. Both exhibit thermal instability at...

Given the prevalence of fluorescence spectroscopy in biological systems, and the prevalence of pterin derivatives throughout biological systems, presented here is an assessment of the two-photon absorption spectroscopy as it applies to a range of the most commonly studied pterin derivatives. QR-CAMB3LYP//ccpVTZ calculations suggest that the use of...

Hypoxic tumours are a major problem for cancer photodynamic therapy. Here, we show that photoredox catalysis can provide an oxygen-independent mechanism of action to combat this problem. We have designed a highly oxidative Ir(iii) photocatalyst, [Ir(ttpy)(pq)Cl]PF6 ([1]PF6, where ‘ttpy’ represents 4′-(p-tolyl)-2,2′:6′,2′′-terpyridine and ‘pq’ repre...

In this investigation we considered both the scalar and 3-D vector-based measures of bonding using next generation quantum theory of atoms in molecules (QTAIM), constructed from the preferred direction of electronic charge density accumulation, to better understand the photo-chemical reaction associated with of the formation of benzvalene from benz...

We present herein the first comprehensive study of the one‐ and two‐photon absorption of Fe(CO)5 utilising a hierarchy of linear‐ and quadratic‐response coupled cluster (LR‐ and QR‐CC) methodologies to provide an in‐depth characterisation, as well as potential energy curves for axial and equatorial bond dissociations, highlighting the state crossin...

Photodynamic therapy can be used to introduce novel mechanisms of killing cancer cells that overcome resistance. In their Communication (DOI: 10.1002/anie.201709082) P. B. O'Connor, H. Chao, P. J. Sadler et al. describe luminescent organoiridium complexes, with long-lived excited states, which selectively damage cancer cells upon activation by two-...

Strongly luminescent iridium(III) complexes, [Ir(C,N)2(S,S)]⁺ (1) and [Ir(C,N)2(O,O)] (2), containing C,N (phenylquinoline), O,O (diketonate), or S,S (dithione) chelating ligands, have been characterized by X-ray crystallography and DFT calculations. Their long phosphorescence lifetimes in living cancer cells give rise to high quantum yields for th...

Strongly luminescent iridium(III) complexes, [Ir(C,N)2(S,S)]+ (1) and [Ir(C,N)2(O,O)] (2), containing C,N (phenylquinoline), O,O (diketonate), or S,S (dithione) chelating ligands, have been characterized by X-ray crystallography and DFT calculations. Their long phosphorescence lifetimes in living cancer cells give rise to high quantum yields for th...

Cyclopropylamines, inhibitors of monoamine oxidases (MAO) and lysine-specific demethylase (LSD1), provide a useful structural scaffold for the design of mechanism-based inhibitors for the therapy of depression and cancer. For new compounds with the less common cis relationship and with an alkoxy substituent at the 2-position of the cyclopropyl ring...