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Co(NCS)2(abpt)2 and Ni(NCS)2(abpt)2 [abpt is 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole]: structural characterization of polymorphs A and B (2021)
Journal Article
Mason, H. E., Howard, J. A., & Sparkes, H. A. (2021). Co(NCS)2(abpt)2 and Ni(NCS)2(abpt)2 [abpt is 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole]: structural characterization of polymorphs A and B. Acta Crystallographica Section C: Structural Chemistry, 77(12), 777-781. https://doi.org/10.1107/s2053229621010251

The synthesis and structures of bis­[4-amino-3,5-bis­(pyridin-2-yl)-1,2,4-triazole-κ2N2,N3]bis­(thio­cyanato-κN)cobalt(II), [Co(NCS)2(C12H10N6)2] or Co(NCS)2(abpt)2, and bis­[4-amino-3,5-bis­(pyridin-2-yl)-1,2,4-triazole-κ2N2,N3]bis­(thio­cyan­ato-κN... Read More about Co(NCS)2(abpt)2 and Ni(NCS)2(abpt)2 [abpt is 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole]: structural characterization of polymorphs A and B.

Selected solid-state behaviour of three di-tert-butyl-substituted N-salicylideneaniline derivatives: temperature-induced phase transitions and chromic behaviour (2021)
Journal Article
Mason, H. E., Howard, J. A., & Sparkes, H. A. (2021). Selected solid-state behaviour of three di-tert-butyl-substituted N-salicylideneaniline derivatives: temperature-induced phase transitions and chromic behaviour. Acta Crystallographica Section C: Structural Chemistry, 77(10), 659-667. https://doi.org/10.1107/s2053229621008780

The synthesis, single-crystal structures and chromic behaviour of three related Schiff bases, namely, (E)-2,4-di-tert-butyl-6-{[(4-fluoro­phen­yl)imino]­meth­yl}phenol, C21H26FNO, 1, (E)-2,4-di-tert-butyl-6-{[(4-chloro­phen­yl)imino]­meth­yl}phenol,... Read More about Selected solid-state behaviour of three di-tert-butyl-substituted N-salicylideneaniline derivatives: temperature-induced phase transitions and chromic behaviour.

Structural studies into the spin crossover behaviour of Fe(abpt)2(NCS)2 polymorphs B and D (2021)
Journal Article
Mason, H. E., Musselle-Sexton, J. R., Howard, J. A., Probert, M. R., & Sparkes, H. A. (2021). Structural studies into the spin crossover behaviour of Fe(abpt)2(NCS)2 polymorphs B and D. New Journal of Chemistry, 45(31), 14014-14023. https://doi.org/10.1039/d1nj02607k

The spin-crossover behaviour of [Fe(abpt)2(NCS)2] (abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) polymorphs B and D has been studied using single crystal X-ray diffraction to monitor changes in structural features. High pressure single crystal... Read More about Structural studies into the spin crossover behaviour of Fe(abpt)2(NCS)2 polymorphs B and D.

A reversible hydrogen‐bond isomerization triggered by an abrupt spin crossover near room temperature (2020)
Journal Article
Jornet-Mollá, V., Giménez-Saiz, C., Yufit, D. S., Howard, J. A., & Romero, F. M. (2021). A reversible hydrogen‐bond isomerization triggered by an abrupt spin crossover near room temperature. Chemistry - A European Journal, 27(2), 740-750. https://doi.org/10.1002/chem.202003654

The spin crossover salt [Fe(bpp) 2 ](isonicNO) 2 ·2.4H 2 O ( 1 ·2.4H 2 O) (bpp = 2,6‐bis(pyrazol‐3‐yl)pyridine; isonicNO = isonicotinate N‐oxide anion) exhibits a very abrupt spin crossover at T 1 /2 = 274.4 K. This triggers a supramolecular linkage... Read More about A reversible hydrogen‐bond isomerization triggered by an abrupt spin crossover near room temperature.

Interplay between spin crossover and proton migration along short strong hydrogen bonds (2020)
Journal Article
Jornet-Mollá, V., Giménez-Saiz, C., Cañadillas-Delgado, L., Yufit, D. S., Howard, J. A., & Romero, F. M. (2021). Interplay between spin crossover and proton migration along short strong hydrogen bonds. Chemical Science, 12(3), 1038-1053. https://doi.org/10.1039/d0sc04918b

The iron(II) salt [Fe(bpp)2](isonicNO)2·HisonicNO·5H2O (1) (bpp = 2,6-bis(pyrazol-3-yl)pyridine; isonicNO = isonicotinate N-oxide anion) undergoes a partial spin crossover (SCO) with symmetry breaking at T1 = 167 K to a mixed-spin phase (50% high-spi... Read More about Interplay between spin crossover and proton migration along short strong hydrogen bonds.

(E)-4-Bromo-2-[(phenylimino)methyl]phenol: a new polymorph and thermochromism (2020)
Journal Article
Mason, H. E., Howard, J. A., & Sparkes, H. A. (2020). (E)-4-Bromo-2-[(phenylimino)methyl]phenol: a new polymorph and thermochromism. Acta Crystallographica Section C: Structural Chemistry, 76(11), Article C76. https://doi.org/10.1107/s2053229620011560

A new polymorph of (E)-4-bromo-2-[(phenylimino)methyl]phenol, C13H10Br-NO, is reported, together with a low-temperature structure determination of thepreviously published polymorph. Both polymorphs were found to have anintramolecular O—HN hydrogen... Read More about (E)-4-Bromo-2-[(phenylimino)methyl]phenol: a new polymorph and thermochromism.

Highly Stable Supramolecular Donor–Acceptor Complexes Involving a Bis(18-Crown-6)azobenzene as Weak Donor: Structure–Property Relationships (2020)
Journal Article
Ushakov, E. N., Martyanov, T. P., Vedernikov, A. I., Efremova, A. A., Moiseeva, A. A., Kuz’mina, L. G., Dmitrieva, S. N., Howard, J. A., & Gromov, S. P. (2020). Highly Stable Supramolecular Donor–Acceptor Complexes Involving a Bis(18-Crown-6)azobenzene as Weak Donor: Structure–Property Relationships. ACS Omega, 5(40), 25993-26004. https://doi.org/10.1021/acsomega.0c03441

The physicochemical properties of highly stable supramolecular donor–acceptor (D–A) complexes of a bis(18-crown-6)azobenzene (weak π-donor) with a series of bis(ammonioalkyl) derivatives of viologen-like molecules (π-acceptors) in acetonitrile were s... Read More about Highly Stable Supramolecular Donor–Acceptor Complexes Involving a Bis(18-Crown-6)azobenzene as Weak Donor: Structure–Property Relationships.

Synthesis and structures of three isoxazole-containing Schiff bases (2020)
Journal Article
Mason, H. E., Howard, J. A., & Sparkes, H. A. (2020). Synthesis and structures of three isoxazole-containing Schiff bases. Acta Crystallographica Section C: Structural Chemistry, 76(9), 927-931. https://doi.org/10.1107/s2053229620010530

The synthesis and structures of three isoxazole-containing Schiff bases are reported, namely, (E)-2-{[(isoxazol-3-yl)imino]­meth­yl}phenol, C10H8N2O2, (E)-2-{[(5-methyl­isoxazol-3-yl)imino]­meth­yl}phenol, C11H10N2O2, and (E)-2,4-di-tert-butyl-6-{[(i... Read More about Synthesis and structures of three isoxazole-containing Schiff bases.

Resolving Alternative Organic Crystal Structures using Density Functional Theory and NMR Chemical Shifts (2020)
Journal Article
Widdifield, C., Farrell, J., Cole, J., Howard, J., & Hodgkinson, P. (2020). Resolving Alternative Organic Crystal Structures using Density Functional Theory and NMR Chemical Shifts. Chemical Science, 11(11), 2987-2992. https://doi.org/10.1039/c9sc04964a

Alternative (‘repeat’) determinations of organic crystal structures deposited in the Cambridge Structural Database are analysed to characterise the nature and magnitude of the differences between structure solutions obtained by diffraction methods. O... Read More about Resolving Alternative Organic Crystal Structures using Density Functional Theory and NMR Chemical Shifts.

Pseudodimeric complexes of 4-styrylpyridine derivatives: Structure–property relationships and a stereospecific [2+2]-cross-photocycloaddition in solution (2019)
Journal Article
Martyanov, T. P., Vedernikov, A. I., Ushakov, E. N., Sazonov, S. K., Aleksandrova, N. A., Lobova, N. A., Kuz'mina, L. G., Howard, J. A., Alfimov, M. V., & Gromov, S. P. (2020). Pseudodimeric complexes of 4-styrylpyridine derivatives: Structure–property relationships and a stereospecific [2+2]-cross-photocycloaddition in solution. Dyes and Pigments, 172, https://doi.org/10.1016/j.dyepig.2019.107825

The study addresses the spectral and photochemical properties of N-(3-ammoniopropyl)-4-styrylpyridinium diperchlorate and its substituted analogs containing either electron-donating (OMe, SMe, NMe2) or electron-withdrawing (NO2, Cl) groups on the ben... Read More about Pseudodimeric complexes of 4-styrylpyridine derivatives: Structure–property relationships and a stereospecific [2+2]-cross-photocycloaddition in solution.

Self-assembly of cucurbiturils and cyclodextrins to supramolecular millstones with naphthalene derivatives capable of translocations in the host cavities (2019)
Journal Article
Vedernikov, A. I., Lobova, N. A., Kuz’mina, L. G., Fomina, M. V., Strelenko, Y. A., Howard, J. A., & Gromov, S. P. (2019). Self-assembly of cucurbiturils and cyclodextrins to supramolecular millstones with naphthalene derivatives capable of translocations in the host cavities. New Journal of Chemistry, 43(9), 3673-3689. https://doi.org/10.1039/c8nj04685a

Activated niobium and tantalum imido complexes: from tuneable polymerization to selective ethylene dimerization systems (2019)
Journal Article
Messinis, A., Batsanov, A., Howard, J., Hanton, M., & Dyer, P. W. (2019). Activated niobium and tantalum imido complexes: from tuneable polymerization to selective ethylene dimerization systems. ChemCatChem, 11(6), 1756-1764. https://doi.org/10.1002/cctc.201801849

The niobium and tantalum imido complexes [CpMCl2(NDipp)], [MCl3(NR)(dme)] (R = tBu, Ph, 2,6‐iPr2C6H3 (Dipp), and Mes), and [TaCl3(NDipp)(tmeda)] were tested in combination with EtAlCl2 for the dimerization of ethylene. The niobium systems afforded di... Read More about Activated niobium and tantalum imido complexes: from tuneable polymerization to selective ethylene dimerization systems.

Supramolecular Organogels Based on N-Benzyl, N′-Acylbispidinols (2019)
Journal Article
Medved’ko, A., Dalinger, A., Nuriev, V., Semashko, V., Filatov, A., Ezhov, A., Churakov, A., Howard, J., Shiryaev, A., Baranchikov, A., Ivanov, V., & Vatsadze, S. (2019). Supramolecular Organogels Based on N-Benzyl, N′-Acylbispidinols. Nanomaterials, 9(1), Article 89. https://doi.org/10.3390/nano9010089

The acylation of unsymmetrical N-benzylbispidinols in aromatic solvents without an external base led to the formation of supramolecular gels, which possess different thicknesses and degrees of stability depending on the substituents in para-positions... Read More about Supramolecular Organogels Based on N-Benzyl, N′-Acylbispidinols.

[Fe(abpt)2(NCSe)2] polymorph A: structural studies into the spin crossover behaviour (2018)
Journal Article
Mason, H. E., Hamilton, M. L., Howard, J. A., & Sparkes, H. A. (2018). [Fe(abpt)2(NCSe)2] polymorph A: structural studies into the spin crossover behaviour. New Journal of Chemistry, 42(22), 18028-18037. https://doi.org/10.1039/c8nj03627f

The spin crossover behaviour of [Fe(abpt)2(NCSe)2] (abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) polymorph A has been examined using single crystal X-ray diffraction and variable temperature UV-Vis transmission spectroscopy. The crystal struc... Read More about [Fe(abpt)2(NCSe)2] polymorph A: structural studies into the spin crossover behaviour.

Bis(imido) tungsten complexes: efficient pre-catalysts for the homogeneous dimerization of ethylene (2018)
Journal Article
Messinis, A., Batsanov, A. S., Wright, W. R., Howard, J. A., Hanton, M. J., & Dyer, P. W. (2018). Bis(imido) tungsten complexes: efficient pre-catalysts for the homogeneous dimerization of ethylene. ACS Catalysis, 8(12), 11249-11263. https://doi.org/10.1021/acscatal.8b02202

The ethylene dimerization performance of a range of bis(imido)tungsten pre-catalysts, after activation with aluminum co-catalysts, has been assessed. The best performing system achieved an activity of 409,410 (mol C2H4)(mol W)–1h–1 [79.6 wt% 1-butene... Read More about Bis(imido) tungsten complexes: efficient pre-catalysts for the homogeneous dimerization of ethylene.

Coordination properties of a 2-aryl-1,3,2-dioxaphospholane (2018)
Journal Article
Coffer, P. K., Dillon, K. B., Howard, J. A., Probert, M. R., & Shepherd, H. J. (2018). Coordination properties of a 2-aryl-1,3,2-dioxaphospholane. Inorganica Chimica Acta, 479, 24-29. https://doi.org/10.1016/j.ica.2018.04.030

The coordination properties of the 2-aryl-1,3,2-dioxaphospholane 2,6-(CF3)2C6H3P(OCH2)21 (L) have been investigated, by reaction with elemental selenium in solution to form the phosphorus(V) oxidation product 2,6-(CF3)2C6H3P(Se)(OCH2)22, and with met... Read More about Coordination properties of a 2-aryl-1,3,2-dioxaphospholane.

Probing the accuracy and precision of Hirshfeld atom refinement with HARt interfaced with Olex2 (2018)
Journal Article
Fugel, M., Jayatilaka, D., Hupf, E., Overgaard, J., Hathwar, V. R., Macchi, P., …Grabowsky, S. (2018). Probing the accuracy and precision of Hirshfeld atom refinement with HARt interfaced with Olex2. IUCrJ, 5(1), 32-44. https://doi.org/10.1107/s2052252517015548

Hirshfeld atom refinement (HAR) is a novel X-ray structure refinement technique that employs aspherical atomic scattering factors obtained from stockholder partitioning of a theoretically determined tailor-made static electron density. HAR overcomes... Read More about Probing the accuracy and precision of Hirshfeld atom refinement with HARt interfaced with Olex2.

Structural and spectroscopic characterisation of the spin crossover in [Fe(abpt)2(NCS)2] polymorph A (2016)
Journal Article
Mason, H. E., Li, W., Carpenter, M. A., Hamilton, M., Howard, J. A., & Sparkes, H. A. (2016). Structural and spectroscopic characterisation of the spin crossover in [Fe(abpt)2(NCS)2] polymorph A. New Journal of Chemistry, 40(3), 2466-2478. https://doi.org/10.1039/c5nj02359a

A crystallographic and solid state spectroscopic study of the spin crossover behaviour of [Fe(abpt)2(NCS)2] (abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) polymorph A is reported. Structural features including crystallographic cell parameters,... Read More about Structural and spectroscopic characterisation of the spin crossover in [Fe(abpt)2(NCS)2] polymorph A.

Insights into the Crystallisation Process from Anhydrous, Hydrated and Solvated Crystal Forms of Diatrizoic Acid (2014)
Journal Article
Fucke, K., McIntyre, G. J., Lemee-Cailleay, M.-H., Wilkinson, C., Edwards, A. J., Howard, J. A., & Steed, J. W. (2015). Insights into the Crystallisation Process from Anhydrous, Hydrated and Solvated Crystal Forms of Diatrizoic Acid. Chemistry - A European Journal, 21(3), 1036-1047. https://doi.org/10.1002/chem.201404693

Diatrizoic acid (DTA), a clinically used X-ray contrast agent, crystallises in two hydrated, three anhydrous and nine solvated solid forms, all of which have been characterised by X-ray crystallography. Single-crystal neutron structures of DTA dihydr... Read More about Insights into the Crystallisation Process from Anhydrous, Hydrated and Solvated Crystal Forms of Diatrizoic Acid.