Publications

Members of the YCG are involved in some of the leading crystallographic research to emerge from the UK. Below is a list of recent publications authored by some of our members. Any member can propose a paper published this year where he/she is one of the authors. Please send the paper details to the YCG committee and we will put it online.

2017

  • [DOI] L. K. Mapp, S. J. Coles, and S. Aitipamula, “Novel solid forms of lonidamine: crystal structures and physicochemical properties,” Crystengcomm, p. -, 2017.
    [Bibtex]
    @Article{C7CE00651A,
    author ="Mapp, Lucy K. and Coles, Simon J. and Aitipamula, Srinivasulu",
    title ="Novel solid forms of lonidamine: crystal structures and physicochemical properties",
    journal ="CrystEngComm",
    year ="2017",
    pages ="-",
    publisher ="The Royal Society of Chemistry",
    doi ="10.1039/C7CE00651A",
    url ="http://dx.doi.org/10.1039/C7CE00651A",
    abstract ="Lonidamine finds potential applications in cancer treatments{,} and its current marketed solid form{,} the sodium salt{,} displays poor solubility. The presence of a single carboxylic acid group makes it an ideal target for co-crystal design as design strategies involving carboxylic acid groups are well-established. CSD statistics combined with known hydrogen bonding preferences allowed suitable co-former selection which resulted in nine new multicomponent crystals with pharmaceutically acceptable co-formers. These included co-crystals{,} salts and some hybrid (co-crystal salt) structures. All the solid forms were characterized by X-ray diffraction techniques with subsequent measurement of physicochemical properties{,} such as stability{,} solubility{,} and dissolution rate. It was found that the co-formers were able to modulate the properties of lonidamine."}

2015

  • [DOI] J. G. P. Wicker and R. I. Cooper, “Will it crystallise? predicting crystallinity of molecular materials,” Crystengcomm, p. -, 2015.
    [Bibtex]
    @Article{CWicker2015,
    author ="Wicker, Jerome G. P. and Cooper, Richard I.",
    title ="Will it crystallise? Predicting crystallinity of molecular materials",
    journal ="CrystEngComm",
    year ="2015",
    pages ="-",
    publisher ="The Royal Society of Chemistry",
    doi ="10.1039/C4CE01912A",
    url ="http://dx.doi.org/10.1039/C4CE01912A",
    abstract ="Predicting and controlling crystallinity of molecular materials has applications in a crystal engineering context{,} as well as process control and formulation in the pharmaceutical industry. Here{,} we present a machine learning approach to this problem which uses a large input training set which is classified on a single measurable outcome: does a substance have a reasonable probability of forming good quality crystals. While the related problem of crystal structure prediction requires reliable calculation of three dimensional molecular conformations{,} the method employed here for predicting crystallisation propensity uses only {"}two dimensional{"} information consisting of atom types and connectivity. We show that an error rate lower than 10% can be achieved against unseen test data. The predictive model was also tested in a blind screen of a set of compounds which do not have crystal structures reported in the literature{,} and we found it to have a 79% classification accuracy. Analysis of the most significant descriptors used in the classification shows that the number of rotatable bonds and a molecular connectivity index are key in determining crystallisation propensity and using these two measures alone can give 80% accurate classification of unseen test data."}

2014

  • [DOI] T. D. Bennett, J. Sotelo, J. Tan, and S. Moggach, “Mechanical properties of zeolitic metal-organic frameworks: mechanically flexible topologies and stabilization against structural collapse,” Crystengcomm, p. -, 2014.
    [Bibtex]
    @Article{Bennett2014,
    author ="Bennett, Thomas Douglas and Sotelo, Jorge and Tan, Jin-Chong and Moggach, Steve",
    title ="Mechanical Properties of Zeolitic Metal-Organic Frameworks: Mechanically Flexible Topologies and Stabilization against Structural Collapse",
    journal ="CrystEngComm",
    year ="2014",
    pages ="-",
    publisher ="The Royal Society of Chemistry",
    doi ="10.1039/C4CE02145B",
    url ="http://dx.doi.org/10.1039/C4CE02145B",
    abstract ="We report on the elastic moduli of two large pore zeolitic metal-organic frameworks (rho- and sod-ZMOF). Their extremely low (1.93 GPa){,} and intermediate (5.57 GPa) moduli are compared with those of zeolites of identical topologies{,} finding similarities relative to frameworks in the same family. Whilst collapse upon ball-milling occurs quickly{,} common solvents can be used to stabilise the structure{,} a facile method which may be applicable to other porous hybrid frameworks."}
  • [DOI] S. Hunt, M. Cliffe, J. A. Hill, A. B. Cairns, N. P. Funnell, and A. Goodwin, “Flexibility transition and guest-driven reconstruction in a ferroelastic metal-organic framework,” Crystengcomm, p. -, 2014.
    [Bibtex]
    @Article{Hunt2014,
    author ="Hunt, Sarah and Cliffe, Matthew and Hill, Joshua A and Cairns, Andrew B and Funnell, Nicholas P and Goodwin, Andrew",
    title ="Flexibility Transition and Guest-Driven Reconstruction in a Ferroelastic Metal-Organic Framework",
    journal ="CrystEngComm",
    year ="2014",
    pages ="-",
    publisher ="The Royal Society of Chemistry",
    doi ="10.1039/C4CE01572J",
    url ="http://dx.doi.org/10.1039/C4CE01572J",
    abstract ="The metal--organic framework copper(I) tricyanomethanide{,} Cu(tcm){,} undergoes a ferroelastic transition on cooling below Tf=240 K. Thermal expansion measurements reveal an order-of-magnitude variation in framework flexibility across Tf. The low-temperature phase [small alpha]-Cu(tcm) exhibits colossal positive and negative thermal expansion that is the strongest ever reported for a framework material. On exposure to acetonitrile{,} Cu(tcm) undergoes a reconstructive solid-phase transition to acetonitrilocopper(I) tricyanomethanide. This transition can be reversed by heating under vacuum. Infrared spectroscopy measurements are sensitive to the phase change{,} suggesting that Cu(tcm) may find application in solid-phase acetonitrile sensing."}
  • [DOI] S. C. McKellar, A. J. Graham, D. R. Allan, I. M. H. Mohideen, R. E. Morris, and S. A. Moggach, “The effect of pressure on the post-synthetic modification of a nanoporous metal-organic framework,” Nanoscale, vol. 6, pp. 4163-4173, 2014.
    [Bibtex]
    @Article{McKellar2014,
    author ="McKellar, Scott C. and Graham, Alexander J. and Allan, David R. and Mohideen, M. Infas H. and Morris, Russell E. and Moggach, Stephen A.",
    title ="The effect of pressure on the post-synthetic modification of a nanoporous metal-organic framework",
    journal ="Nanoscale",
    year ="2014",
    volume ="6",
    issue ="8",
    pages ="4163-4173",
    publisher ="The Royal Society of Chemistry",
    doi ="10.1039/C3NR04161A",
    url ="http://dx.doi.org/10.1039/C3NR04161A",
    abstract ="Here we report four post-synthetic modifications{,} including the first ever example of a high pressure-induced post-synthetic modification{,} of a porous copper-based metal-organic framework. Ligand exchange with a water ligand at the axial metal site occurs with methanol{,} acetonitrile{,} methylamine and ethylamine within a single-crystal and without the need to expose a free metal site prior to modification{,} resulting in significant changes in the pore size{,} shape and functionality. Pressure experiments carried out using isopropylalcohol and acetaldehyde{,} however{,} results in no ligand exchange. By using these solvents as hydrostatic media for high-pressure single-crystal X-ray diffraction experiments{,} we have investigated the effect of ligand exchange on the stability and compressibility of the framework and demonstrate that post-synthetic ligand exchange is very sensitive to both the molecular size and functionality of the exchanged ligand. We also demonstrate the ability to force hydrophilic molecules into hydrophobic pores using high pressures which results in a pressure-induced chemical decomposition of the Cu-framework."}
  • [DOI] L. H. Thomas, A. R. Klapwijk, C. Wales, and C. C. Wilson, “Intermolecular hydrogen transfer and solubility tuning in multi-component molecular crystals of the api piroxicam,” Crystengcomm, vol. 16, pp. 5924-5932, 2014.
    [Bibtex]
    @Article{Thomas2014,
    author ="Thomas, Lynne H. and Klapwijk, Anneke R. and Wales, Craig and Wilson, Chick C.",
    title ="Intermolecular hydrogen transfer and solubility tuning in multi-component molecular crystals of the API piroxicam",
    journal ="CrystEngComm",
    year ="2014",
    volume ="16",
    issue ="26",
    pages ="5924-5932",
    publisher ="The Royal Society of Chemistry",
    doi ="10.1039/C4CE00246F",
    url ="http://dx.doi.org/10.1039/C4CE00246F",
    abstract ="A series of twelve multi-component molecular crystals of the active pharmaceutical ingredient (API) piroxicam (PX) have been synthesised and their structures analysed with respect to their supramolecular motifs and degree of intermolecular hydrogen transfer observed on formation of the various complexes. The multi-component crystals of PX formed with a series of basic N-heterocycles are contrasted with those formed with strong haloanilic acids{,} with PX found to adopt different ionisation states. The effect of the formation of these multi-component molecular crystals on the physical property of solubility{,} often crucial in API formulation{,} has been investigated and these solubility determinations are compared with those of the parent PX material. Enhanced solubility is evident in some of the multi-component crystals formed."}
  • [DOI] K. Wittering, J. King, L. H. Thomas, and C. C. Wilson, “From evaporative to cooling crystallisation: an initial co-crystallisation study of cytosine and its fluorinated derivative with 4-chloro-3,5-dinitrobenzoic acid,” Crystals, vol. 4, iss. 2, pp. 123-140, 2014.
    [Bibtex]
    @Article{Wittering2014,
    AUTHOR = {Wittering, Kate and King, Josh and Thomas, Lynne H. and Wilson, Chick C.},
    TITLE = {From Evaporative to Cooling Crystallisation: An Initial Co-Crystallisation Study of Cytosine and Its Fluorinated Derivative with 4-chloro-3,5-dinitrobenzoic Acid},
    JOURNAL = {Crystals},
    VOLUME = {4},
    YEAR = {2014},
    NUMBER = {2},
    PAGES = {123--140},
    URL = {http://www.mdpi.com/2073-4352/4/2/123},
    ISSN = {2073-4352},
    DOI = {10.3390/cryst4020123}
    }

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