Dr James Walton's Outputs (21)

Aggregation-induced emission switch showing high contrast mehanofluorochromism and solvatofluorochromism: Specifically detects HSO3− in bioimaging studies (2023)
Journal Article
Das, S., Pratim Das, P., Walton, J. W., Kheng Quah, C., Ghoshal, K., & Bhattacharyya, M. (2023). Aggregation-induced emission switch showing high contrast mehanofluorochromism and solvatofluorochromism: Specifically detects HSO3− in bioimaging studies. Dyes and Pigments, 217, Article 111413. https://doi.org/10.1016/j.dyepig.2023.111413

In this work, a novel mechanoresponsive luminescent (MRL) and aggregation induced emission (AIE) switch, 2-(4-((9-butyl-9H-carbazol-3-yl)ethynyl)benzylidene)malononitrile (CABM) has been synthesized by a perfect blending of the carbazole-based triple... Read More about Aggregation-induced emission switch showing high contrast mehanofluorochromism and solvatofluorochromism: Specifically detects HSO3− in bioimaging studies.

Water-soluble copper pyrithione complexes with cytotoxic and antibacterial activity (2023)
Journal Article
Mishra, A., Djoko, K. Y., Lee, Y.-H., Lord, R. M., Kaul, G., Akhir, A., Saxena, D., Chopra, S., & Walton, J. W. (2023). Water-soluble copper pyrithione complexes with cytotoxic and antibacterial activity. Organic and Biomolecular Chemistry, 21(12), 2539-2544. https://doi.org/10.1039/d2ob01224c

Copper Pyrithione, [Cu(PyS)2] has shown excellent biological activity against cancer cells and bacterial cells, however, it has extremely low aqueous solubility, limiting its applicability. Herein, we report a series of PEG-substituted pyrithione cop... Read More about Water-soluble copper pyrithione complexes with cytotoxic and antibacterial activity.

Biotinylated selenocyanates: Potent and selective cytostatic agents (2023)
Journal Article
Roldán-Peña, J. M., Puerta, A., Dinić, J., Jovanović Stojanov, S., González-Bakker, A., Hicke, F. J., Mishra, A., Piyasaengthong, A., Maya, I., Walton, J. W., Pešić, M., Padrón, J. M., Fernández-Bolaños, J. G., & López, Ó. (2023). Biotinylated selenocyanates: Potent and selective cytostatic agents. Bioorganic Chemistry, 133, Article 106410. https://doi.org/10.1016/j.bioorg.2023.106410

Most of the currently available cytotoxic agents for tackling cancer are devoid of selectivity, thus causing severe side-effects. This situation stimulated us to develop new antiproliferative agents with enhanced affinity towards tumour cells. We foc... Read More about Biotinylated selenocyanates: Potent and selective cytostatic agents.

A new ratiometric switch “two-way” detects hydrazine and hypochlorite via a “dye-release” mechanism with a PBMC bioimaging study (2022)
Journal Article
Das, S., Patra, L., Pratim Das, P., Ghoshal, K., Gharami, S., Walton, J. W., Bhattacharyya, M., & Mondal, T. K. (2022). A new ratiometric switch “two-way” detects hydrazine and hypochlorite via a “dye-release” mechanism with a PBMC bioimaging study. Physical Chemistry Chemical Physics, 24(35), 20941-20952. https://doi.org/10.1039/d2cp02482a

A new ratiometric fluorescent probe (E)-2-(benzo[d]thiazol-2-yl)-3-(8-methoxyquinolin-2-yl)acrylonitrile (HQCN) was synthesised by the perfect blending of quinoline and a 2-benzothiazoleacetonitrile unit. In a mixed aqueous solution, HQCN reacts with... Read More about A new ratiometric switch “two-way” detects hydrazine and hypochlorite via a “dye-release” mechanism with a PBMC bioimaging study.

Enolate SNAr of unactivated arenes via [(η6-arene)RuCp]+ intermediates (2022)
Journal Article
Williams, L. J., Bhonoah, Y., & Walton, J. W. (2022). Enolate SNAr of unactivated arenes via [(η6-arene)RuCp]+ intermediates. Chemical Communications, 58(80), 11240-11243. https://doi.org/10.1039/d2cc02508f

A series of complexes of the general formula [(η6-arene)RuCp][PF6] (where arene = aryl halides or nitroarenes) were synthesised and the arene ring was found to be reactive towards an intermolecular nucleophilic aromatic substitution (SNAr) reaction w... Read More about Enolate SNAr of unactivated arenes via [(η6-arene)RuCp]+ intermediates.

Novel ruthenium complexes bearing bipyridine-based and N-heterocyclic carbene-supported pyridine (NCN) ligands: the influence of ligands on catalytic transfer hydrogenation of ketones (2021)
Journal Article
Piyasaengthong, A., Williams, L. J., Yufit, D. S., & Walton, J. W. (2022). Novel ruthenium complexes bearing bipyridine-based and N-heterocyclic carbene-supported pyridine (NCN) ligands: the influence of ligands on catalytic transfer hydrogenation of ketones. Dalton Transactions, 51(1), 340-351. https://doi.org/10.1039/d1dt03240b

Transfer hydrogenation (TH) is a powerful synthetic tool in the production of secondary alcohols from ketones by using a non-H2 hydrogen source along with metal catalysts. Among homogeneous catalysts, Ru(II) complexes are the most efficient catalysts... Read More about Novel ruthenium complexes bearing bipyridine-based and N-heterocyclic carbene-supported pyridine (NCN) ligands: the influence of ligands on catalytic transfer hydrogenation of ketones.

Human peripheral blood mononuclear cells targeted multidimensional switch for selective detection of HSO3− anion (2021)
Journal Article
Das, S., Das, P. P., Walton, J. W., Ghoshal, K., Patra, L., Bhattacharyya, M., Mondal, T. K., & Thomas, S. (2022). Human peripheral blood mononuclear cells targeted multidimensional switch for selective detection of HSO3− anion. Dyes and Pigments, 198, Article 109966. https://doi.org/10.1016/j.dyepig.2021.109966

A new ratiometric π-conjugated luminophore with donor-acceptor (D- π- A) network CM {(E)-2-(4-(2-(9-butyl-9H-carbazol-3-yl)vinyl)benzylidine)malononitrile} has been synthesized by malononitrile conjugated carbazole dye with an intervening p-styryl sp... Read More about Human peripheral blood mononuclear cells targeted multidimensional switch for selective detection of HSO3− anion.

Comparative analysis of lanthanide excited state quenching by electronic energy and electron transfer processes (2021)
Journal Article
Parker, D., Fradgley, J. D., Delbianco, M., Starck, M., Walton, J., & Zwier, J. M. (2022). Comparative analysis of lanthanide excited state quenching by electronic energy and electron transfer processes. Faraday Discussions, 234, 159 - 174. https://doi.org/10.1039/d1fd00059d

The relative sensitivities of structurally related Eu(III) complexes to quenching by electron and energy transfer processes have been compared. In two sets of 9-coordinate complexes based on 1,4,7-triazacyclononane, the Eu emission lifetime decreased... Read More about Comparative analysis of lanthanide excited state quenching by electronic energy and electron transfer processes.

FRET based ratiometric switch for selective sensing of Al3+ with bio-imaging in human peripheral blood mononuclear cells (2021)
Journal Article
Das, S., Pratim Das, P., Walton, J. W., Ghoshal, K., Patra, L., & Bhattacharyya, M. (2021). FRET based ratiometric switch for selective sensing of Al3+ with bio-imaging in human peripheral blood mononuclear cells. New Journal of Chemistry, 45(4), 1853-1862. https://doi.org/10.1039/d0nj05546h

In this work, a triphenylamine and rhodamine-B (donor–acceptor) hybrid switch (TPRH) was rationally designed, synthesised and characterised as a novel fluorescence resonance energy transfer (FRET) ratiometric fluorescent chemosensor for specific sens... Read More about FRET based ratiometric switch for selective sensing of Al3+ with bio-imaging in human peripheral blood mononuclear cells.

As nice as π: aromatic reactions activated by π‐coordination to transition metals (2020)
Journal Article
Williams, L. J., Bhonoah, Y., Wilkinson, L. A., & Walton, J. W. (2021). As nice as π: aromatic reactions activated by π‐coordination to transition metals. Chemistry - A European Journal, 27(11), 3650-3660. https://doi.org/10.1002/chem.202004621

π‐Coordination of aromatic molecules to metals dramatically alters their reactivity. For example, coordinated carbons become more electrophilic and C‐H bonds of coordinated rings become more acidic. For many years, this change in reactivity has been... Read More about As nice as π: aromatic reactions activated by π‐coordination to transition metals.

Anticancer Ruthenium Complexes with HDAC Isoform Selectivity (2020)
Journal Article
Cross, J., Blower, T., Kingdon, A., Pal, R., Picton, D., & Walton, J. (2020). Anticancer Ruthenium Complexes with HDAC Isoform Selectivity. Molecules, 25(10), Article 2383. https://doi.org/10.3390/molecules25102383

The histone deacetylase (HDAC) enzymes have emerged as an important class of molecular targets in cancer therapy, with five inhibitors in clinical use. Recently, it has been shown that a lack of selectivity between the 11 Zn-dependent HDAC isoforms m... Read More about Anticancer Ruthenium Complexes with HDAC Isoform Selectivity.

π-Coordinated arene metal complexes and catalysis (2018)
Book Chapter
Walton, J. W., & Wilkinson, L. A. (2018). π-Coordinated arene metal complexes and catalysis. In N. J. Patmore, & P. I. Elliott (Eds.), Organometallic chemistry (125-171). Royal Society of Chemistry. https://doi.org/10.1039/9781788010672-00125

Metal complexes formed from π-coordination of aromatic groups to metal centres may undergo reactions at the coordinated arene that do not occur for the unbound arene. Upon completion of such reactions, the coordinated arene product can be liberated f... Read More about π-Coordinated arene metal complexes and catalysis.

C–H Activation of π-Arene Ruthenium Complexes (2017)
Journal Article
Wilkinson, L. A., Pike, J. A., & Walton, J. W. (2017). C–H Activation of π-Arene Ruthenium Complexes. Organometallics, 36(22), 4376-4381. https://doi.org/10.1021/acs.organomet.7b00563

We present a C–H activation protocol for aromatic compounds that overcomes the current limitations of the need for a directing group or covalently bound activating groups, by exploiting the increase in C–H acidity of aromatic compounds on π-coordinat... Read More about C–H Activation of π-Arene Ruthenium Complexes.

Perfluorinated HDAC inhibitors as Selective Anticancer Agents (2017)
Journal Article
Walton, J. W., Cross, J. M., Riedel, T., & Dyson, P. (2017). Perfluorinated HDAC inhibitors as Selective Anticancer Agents. Organic and Biomolecular Chemistry, 15(43), 9186-9190. https://doi.org/10.1039/c7ob02339a

A series of potent histone deacetylase inhibitors is presented that incorporate alkyl or perfluorinated alkyl chains. Several new compounds show greater in vitro antiproliferate activity than the clinically approved inhibitor, SAHA. Furthermore, the... Read More about Perfluorinated HDAC inhibitors as Selective Anticancer Agents.

Nucleophilic Trifluoromethylation of Electron-Deficient Arenes (2017)
Journal Article
Pike, J. A., & Walton, J. W. (2017). Nucleophilic Trifluoromethylation of Electron-Deficient Arenes. Chemical Communications, 53(71), https://doi.org/10.1039/c7cc05415g

A novel trifluoromethylation of arenes is presented, which proceeds under mild reaction conditions and has the potential for late-stage functionalisation of pharmaceuticals and agrochemicals. The new reaction allows for the regioselective conversion... Read More about Nucleophilic Trifluoromethylation of Electron-Deficient Arenes.

Anticancer RuII and RhIII Piano-Stool Complexes that are Histone Deacetylase Inhibitors (2016)
Journal Article
Cross, J., Blower, T., Gallagher, N., Gill, J., Rockley, K., & Walton, J. (2016). Anticancer RuII and RhIII Piano-Stool Complexes that are Histone Deacetylase Inhibitors. ChemPlusChem, 81(12), 1276-1280. https://doi.org/10.1002/cplu.201600413

The first examples of RuII and RhIII piano-stool complex histone deacetylase (HDAC) inhibitors are presented. The novel complexes have antiproliferative activity against H460 non-small-cell lung carcinoma cells that is comparable to the clinically us... Read More about Anticancer RuII and RhIII Piano-Stool Complexes that are Histone Deacetylase Inhibitors.

Pyridylphosphinate Metal Complexes: Synthesis, Structural Characterisation and Biological Activity (2016)
Journal Article
Cross, J., Gallagher, N., Gill, J., Jain, M., McNeillis, A., Rockley, K., …Walton, J. (2016). Pyridylphosphinate Metal Complexes: Synthesis, Structural Characterisation and Biological Activity. Dalton Transactions, 45(32), 12807-12813. https://doi.org/10.1039/c6dt01264g

For the first time, a series of 25 pseudo-octahedral pyridylphosphinate metal complexes (Ru, Os, Rh, Ir) has been synthesised and assessed in biological systems. Each metal complex incorporates a pyridylphosphinate ligand, a monodentate halide and a... Read More about Pyridylphosphinate Metal Complexes: Synthesis, Structural Characterisation and Biological Activity.

EuroTracker® dyes : design, synthesis, structure and photophysical properties of very bright europium complexes and their use in bioassays and cellular optical imaging (2014)
Journal Article
Butler, S., Delbianco, M., Lamarque, L., McMahon, B., Neil, E., Pal, R., …Zwier, J. (2015). EuroTracker® dyes : design, synthesis, structure and photophysical properties of very bright europium complexes and their use in bioassays and cellular optical imaging. Dalton Transactions, 44(11), 4791-4803. https://doi.org/10.1039/c4dt02785j

The development of the brightest luminescent europium(III) complexes is traced, including analysis of the C3-symmetric core complex based on a functionalized triazacyclononane and identification of the most suitable strongly absorbing chromophore. St... Read More about EuroTracker® dyes : design, synthesis, structure and photophysical properties of very bright europium complexes and their use in bioassays and cellular optical imaging.

Catalytic SNAr of unactivated aryl chlorides (2014)
Journal Article
Walton, J., & Williams, J. (2015). Catalytic SNAr of unactivated aryl chlorides. Chemical Communications, 51(14), 2786-2789. https://doi.org/10.1039/c4cc07116f

We present nucleophilic aromatic substitution of unsubstituted aryl chlorides via a mechanism that is catalytic in [CpRu(p-cymene)]PF6 and involves a Ru(η6-arylchloride) intermediate. From the spectroscopic evidence we infer that arene exchange is th... Read More about Catalytic SNAr of unactivated aryl chlorides.

Comparative analysis of conjugated alkynyl chromophore-triazacyclononane ligands for sensitized emission of europium and terbium (2014)
Journal Article
Soulié, M., Latzko, F., Bourrier, E., Placide, V., Butler, S. J., Pal, R., …Maury, O. (2014). Comparative analysis of conjugated alkynyl chromophore-triazacyclononane ligands for sensitized emission of europium and terbium. Chemistry - A European Journal, 20(28), 8636 -8646. https://doi.org/10.1002/chem.201402415

A series of europium and terbium complexes based on a functionalized triazacyclononane carboxylate or phosphinate macrocyclic ligand is described. The influence of the anionic group, that is, carboxylate, methylphosphinate, or phenylphosphinate, on t... Read More about Comparative analysis of conjugated alkynyl chromophore-triazacyclononane ligands for sensitized emission of europium and terbium.