Understanding and engineering function in switchable molecular crystals
Lead Research Organisation:
University of Leeds
Department Name: Sch of Chemistry
Abstract
The physical properties of a crystalline material depend on the spacial arrangement of its atoms or molecules, as much as on the molecules themselves. Quite often the same molecules can generate two or more different kinds of crystal, by packing together in different ways, leading to materials that are physically distinct but with the same chemical composition (polymorphs). A compound can often prefer to adopt different crystal polymorph structures under different conditions of temperature or pressure. Thus, when the temperature is changed, the crystal lattice can rearrange itself into a new three-dimensional structure - a phase transition. This is important, for example, in the pharmaceutical industry, for example, where different crystal polymorphs of drug compounds can have different solubilities, with the less soluble form being less active. Crystal phase transitions can also have drastic effects on the properties of conducting, magnetic and photonic materials, where small rearrangements of the atoms in a material have large consequences for how their electrons behave.
One type of phase change that we have been studying for some time is spin-crossover, which is a rearrangement of the electrons in an atom in response to a change in temperature. This is common in some types of transition metal compound, being particularly prevalent in iron chemistry. While the molecules in a material undergo spin-crossover individually, it leads to large changes in their size and shape which are propagated through the material in the solid state. As one molecule undergoes the transition and changes its size, it causes a change in pressure in the crystal lattice that in turn promotes the transition in its nearest neighbours. These effects are transmitted through a crystal lattice at differing rates, depending on the strength of the interactions between molecules. Hence, whether a particular material undergoes spin-crossover abruptly or gradually, with temperature or with time, is controlled by its crystal packing. Spin-crossover is a rather extreme example of a crystallographic phase change, in terms of the changes involved to the structure of the material. But it can serve as a model for other, more general types of crystal phase behaviour.
This project represents a concerted program to improve our understanding of phase changes in crystalline materials, using spin-crossover compounds as a test-bed. We will establish new fundamental principles for engineering phase changes into molecular crystal, that occur under pre-defined conditions (of temperature and/or light irradiation), at different rates, and with the property of hysteresis. As well as synthesising these new materials, this apparently simple objective requires state-of-the-art methods for measuring these structure changes. This will be achieved using new X-ray diffraction techniques, for inducing phase changes in crystals in high yields under controlled conditions, and for interpreting the data that result from these experiments (to deconvolute contributions from the starting and product phases of the material, for example). We will also develop improved methods for simulating the phase change events using computer models, to provide new insight into how the design of the crystal affects the propagation of the phase change through its bulk.
The combination of expertise in our consortium will achieve real advances towards solving a problem, that has only been successfully addressed up to now by trial-and-error.
One type of phase change that we have been studying for some time is spin-crossover, which is a rearrangement of the electrons in an atom in response to a change in temperature. This is common in some types of transition metal compound, being particularly prevalent in iron chemistry. While the molecules in a material undergo spin-crossover individually, it leads to large changes in their size and shape which are propagated through the material in the solid state. As one molecule undergoes the transition and changes its size, it causes a change in pressure in the crystal lattice that in turn promotes the transition in its nearest neighbours. These effects are transmitted through a crystal lattice at differing rates, depending on the strength of the interactions between molecules. Hence, whether a particular material undergoes spin-crossover abruptly or gradually, with temperature or with time, is controlled by its crystal packing. Spin-crossover is a rather extreme example of a crystallographic phase change, in terms of the changes involved to the structure of the material. But it can serve as a model for other, more general types of crystal phase behaviour.
This project represents a concerted program to improve our understanding of phase changes in crystalline materials, using spin-crossover compounds as a test-bed. We will establish new fundamental principles for engineering phase changes into molecular crystal, that occur under pre-defined conditions (of temperature and/or light irradiation), at different rates, and with the property of hysteresis. As well as synthesising these new materials, this apparently simple objective requires state-of-the-art methods for measuring these structure changes. This will be achieved using new X-ray diffraction techniques, for inducing phase changes in crystals in high yields under controlled conditions, and for interpreting the data that result from these experiments (to deconvolute contributions from the starting and product phases of the material, for example). We will also develop improved methods for simulating the phase change events using computer models, to provide new insight into how the design of the crystal affects the propagation of the phase change through its bulk.
The combination of expertise in our consortium will achieve real advances towards solving a problem, that has only been successfully addressed up to now by trial-and-error.
Planned Impact
As described under Academic Beneficiaries, this proposal maps well onto several of EPSRC's current priority areas.
Structural changes in crystalline materials impact many aspects of nature and technology. Examples include the pharmaceutical industry, where different structural forms of the same drug substance can have different efficacies, originating from their different solubilities. Alternative structural forms of conducting, magnetic and ferroelectric materials can have different physical properties, arising from differences in the arrangements of their atoms or molecules that may be quite subtle. Applications in photonics depend on switchable crystals, whose structure and refractive index can be changed rapidly and reversibly upon application of a stimulus. Finally, different forms of biominerals like CaCO3 have different morphologies and mechanical properties, that control their biological functions. An understanding of the relationship between different structure forms of crystalline compounds, and how they interconvert, is of fundamental importance for the exploitation of crystalline materials for societal needs.
A crystallographic phase change is initiated at one or more sites in the crystal (nucleation), before propagating through the bulk (growth). As well as typical phase changes, chemical reactions occurring inside crystals also proceed by the same nucleation and growth process. These range from the light-induced darkening of microcrystalline silver salts in photochromic glass, through force-induced chemical transformations, to more complicated organic photocyclisations and the post-synthetic modification of MOF materials. This proposal is a study of crystallographic phase changes, using a particular type of transition (spin-crossover, SCO) as a test-bed for our new developments. SCO transitions are unusual, in that they can be induced and monitored under thermodynamic and kinetic control using an unprecedented array of experimental techniques. New photocrystallographic methods will allow us to observe the products of SCO switching with new clarity, and measure its propagation through a crystal in real time. New simulation techniques will explain these mechanistic results, and design new switchable lattices in silico. Finally, these insights will allow us to synthesise new SCO crystals with technologically useful functionality. This represents an unprecedented program of engineering of a functional molecular crystal.
This project studies SCO switchable materials as models for more general phase change behaviour, but SCO compounds are strongly applicable in their own right. An SCO transition in a molecular material switches several of its physical properties, including its magnetic moment, colour, dielectric constant and electrical resistance. Moreover some SCO materials show pronounced hysteresis. Within the hysteresis loop, the materials are bistable switches that can be either high- or low-spin depending on their history. Several practical applications of spin-transition materials have been demonstrated, that make use of these properties. They include display and memory devices, with pixels of an SCO material whose colour or dielectric constant is switched by spot-heating and cooling; an electroluminescent device, where an SCO compound quenches light-emission through changes in its electrical resistance; and, using their switchable paramagnetism in a temperature-sensitive MRI contrast agent. Switchable SCO liquid crystals, nanoparticles and thin films have also been achieved. Nearly all these application studies have been carried out using two polymeric compounds, that show hysteresis spanning room temperature in their spin-transitions. This project aims to afford new molecular materials with comparable switching properties by de novo design. Such new materials would allow SCO devices to be prepared by different techniques (spin-coating, for example), opening up new applications of the SCO phenomenon.
Structural changes in crystalline materials impact many aspects of nature and technology. Examples include the pharmaceutical industry, where different structural forms of the same drug substance can have different efficacies, originating from their different solubilities. Alternative structural forms of conducting, magnetic and ferroelectric materials can have different physical properties, arising from differences in the arrangements of their atoms or molecules that may be quite subtle. Applications in photonics depend on switchable crystals, whose structure and refractive index can be changed rapidly and reversibly upon application of a stimulus. Finally, different forms of biominerals like CaCO3 have different morphologies and mechanical properties, that control their biological functions. An understanding of the relationship between different structure forms of crystalline compounds, and how they interconvert, is of fundamental importance for the exploitation of crystalline materials for societal needs.
A crystallographic phase change is initiated at one or more sites in the crystal (nucleation), before propagating through the bulk (growth). As well as typical phase changes, chemical reactions occurring inside crystals also proceed by the same nucleation and growth process. These range from the light-induced darkening of microcrystalline silver salts in photochromic glass, through force-induced chemical transformations, to more complicated organic photocyclisations and the post-synthetic modification of MOF materials. This proposal is a study of crystallographic phase changes, using a particular type of transition (spin-crossover, SCO) as a test-bed for our new developments. SCO transitions are unusual, in that they can be induced and monitored under thermodynamic and kinetic control using an unprecedented array of experimental techniques. New photocrystallographic methods will allow us to observe the products of SCO switching with new clarity, and measure its propagation through a crystal in real time. New simulation techniques will explain these mechanistic results, and design new switchable lattices in silico. Finally, these insights will allow us to synthesise new SCO crystals with technologically useful functionality. This represents an unprecedented program of engineering of a functional molecular crystal.
This project studies SCO switchable materials as models for more general phase change behaviour, but SCO compounds are strongly applicable in their own right. An SCO transition in a molecular material switches several of its physical properties, including its magnetic moment, colour, dielectric constant and electrical resistance. Moreover some SCO materials show pronounced hysteresis. Within the hysteresis loop, the materials are bistable switches that can be either high- or low-spin depending on their history. Several practical applications of spin-transition materials have been demonstrated, that make use of these properties. They include display and memory devices, with pixels of an SCO material whose colour or dielectric constant is switched by spot-heating and cooling; an electroluminescent device, where an SCO compound quenches light-emission through changes in its electrical resistance; and, using their switchable paramagnetism in a temperature-sensitive MRI contrast agent. Switchable SCO liquid crystals, nanoparticles and thin films have also been achieved. Nearly all these application studies have been carried out using two polymeric compounds, that show hysteresis spanning room temperature in their spin-transitions. This project aims to afford new molecular materials with comparable switching properties by de novo design. Such new materials would allow SCO devices to be prepared by different techniques (spin-coating, for example), opening up new applications of the SCO phenomenon.
Organisations
- University of Leeds (Lead Research Organisation)
- National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS) (Collaboration)
- UNIVERSITY OF OXFORD (Collaboration)
- University of Rennes 1 (Collaboration)
- Swiss Federal Institute of Technology in Lausanne (EPFL) (Collaboration)
- University of Bath (Collaboration)
- City University of New York (CUNY) (Collaboration)
- Osaka University (Collaboration)
- Technical University Kaiserslautern (Collaboration)
- University of Warwick (Collaboration)
- Russian Academy of Sciences (Collaboration)
People |
ORCID iD |
Malcolm Halcrow (Principal Investigator) |
Publications
Berdiell IC
(2019)
Supramolecular Iron Metallocubanes Exhibiting Site-Selective Thermal and Light-Induced Spin-Crossover.
in Journal of the American Chemical Society
Berdiell IC
(2021)
The number and shape of lattice solvent molecules controls spin-crossover in an isomorphous series of crystalline solvate salts.
in Chemical communications (Cambridge, England)
Burrows K
(2018)
The speciation of homochiral and heterochiral diastereomers of homoleptic cobalt(II) and zinc(II) PyBox complexes
in Polyhedron
Burrows KE
(2017)
Spin States of Homochiral and Heterochiral Isomers of [Fe(PyBox)2 ]2+ Derivatives.
in Chemistry (Weinheim an der Bergstrasse, Germany)
Capel Berdiell I
(2019)
Molecular squares, coordination polymers and mononuclear complexes supported by 2,4-dipyrazolyl-6H-1,3,5-triazine and 4,6-dipyrazolylpyrimidine ligands.
in Dalton transactions (Cambridge, England : 2003)
Capel Berdiell I
(2021)
Structures and Spin States of Iron(II) Complexes of Isomeric 2,6-Di(1,2,3-triazolyl)pyridine Ligands.
in Inorganic chemistry
Capel Berdiell I
(2018)
An Incomplete Spin Transition Associated with a Z'=1?Z'=24 Crystallographic Symmetry Breaking.
in Chemistry (Weinheim an der Bergstrasse, Germany)
Capel Berdiell I
(2017)
Iron(II) Complexes of 2,4-Dipyrazolyl-1,3,5-triazine Derivatives-The Influence of Ligand Geometry on Metal Ion Spin State.
in Inorganic chemistry
Capel Berdiell I
(2020)
Iron and Silver Complexes of 4-(Imidazol-1-yl)-2,6-di(pyrazol-1-yl)-pyridine ( L ), Including a [Fe 3 (µ-F) 2 F 6 L 8 ] + Assembly
in European Journal of Inorganic Chemistry
Cook LJ
(2016)
Different Spin-State Behaviors in Isostructural Solvates of a Molecular Iron(II) Complex.
in Chemistry (Weinheim an der Bergstrasse, Germany)
Description | We met most of our objectives that were described in the Program of Work. We published structure:function relationships in three new families of spin-crossover materials, which developed the theories about cooperativity in molecular crystals that this grant was intended to prove; worked with the Bath group on crystallography of spin-crossover compounds under pressure or irradiation; and, aided the Warwick group in their development of improved LF-MM and DFT protocols for computational studies on spin-crossover materials. Six collaborative papers have been published so far between members of this Critical Mass network (Leeds/Bath, doi 10.1039/c7cc07990g; 10.1021/ic501402q; 10.1002/chem.201406307; 10.3390/magnetochemistry2010009. Leeds/Warwick, doi 10.1002/anie.201600165. Leeds/Warwick/Bath: doi 10.1002/chem.201704558). Two members of the Critical Mass consortium retired during the final year of the grant, which brought the collaboration to an end. |
Exploitation Route | The design of new functional molecular crystals, to undergo pre-defined phase changes. |
Sectors | Chemicals |
URL | http://www2.warwick.ac.uk/fac/sci/chemistry/research/deeth/deethgroup/mosaic4 |
Description | Publication from this grant has a 2023 Altmetrics score of 8 - doi: 10.1021/acs.inorgchem.8b02289 Publication from this grant has a 2023 Altmetrics score of 5 - 10.1021/jacs.9b08862 Publication from this grant has a 2023 Altmetrics score of 4 - 10.1002/adma.201807334 Publication from this grant had a 2021 Altmetrics score of 4 - 10.1002/chem.202004072 Publication from this grant had a 2019 Altmetrics score of 4 - doi: 1021/ic502726q Publication from this grant had a 2018 Altmetrics score of 4 - doi: 10.1002/chem.201700820 |
First Year Of Impact | 2018 |
Impact Types | Societal |
Title | Data to su+D6:K66pport study of Di-Iron(II) [2+2] Helicates of Bis-(Dipyrazolylpyridine) Ligands - the Influence of the Ligand Linker Group on Spin State Properties |
Description | A diiron(II) complex has been crystallised in three different helicate conformations, which differ in the torsions of the butane-1,4-diyl ligand linker groups. The crystals exhibit a range of spin state properties, including stepwise spin-crossover of the two iron atoms. A related ligand with a rigid pyrid-2,6-diyl spacer forms more a distorted, high-spin diiron(II) helicate structure. |
Type Of Material | Database/Collection of data |
Year Produced | 2022 |
Provided To Others? | Yes |
Impact | None yet. |
URL | https://archive.researchdata.leeds.ac.uk/1045/ |
Title | Data to support study of 2,6-Di(pyrazol-1-yl)pyridine-4-carboxylate Esters with Alkyl Chain Substituents, and their Iron(II) Complexes |
Description | Published dataset associated with the research paper doi: 10.1021/acs.inorgchem.8b02289 |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Impact | None yet |
Title | Data to support study of An Incomplete Spin-Transition Associated with a Z' = 1 to Z' = 24 Crystallographic Symmetry Breaking |
Description | Published dataset associated with the research paper doi: 10.1002/chem.201704896 |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Impact | None yet. |
Title | Data to support study of Elucidating the Structural Chemistry of a Hysteretic Iron(II) Spin-Crossover Compound From its Copper(II) and Zinc(II) Congeners |
Description | Published dataset associated with the research paper doi: 10.1002/chem.202000101 |
Type Of Material | Database/Collection of data |
Year Produced | 2020 |
Provided To Others? | No |
Impact | None yet. |
Title | Data to support study of Gradual Thermal Spin-Crossover Mediated by a Re-Entrant Z' = 1 ? Z' = 6 ? Z' = 1 Phase Transition |
Description | Dataset associated with the research paper doi: 10.1021/acs.inorgchem.7b00071 |
Type Of Material | Database/Collection of data |
Year Produced | 2017 |
Provided To Others? | Yes |
Impact | None yet. |
Title | Data to support study of Influence of Ligand Substituent Conformation on the Spin State of an Iron(II)/Di(pyrazol-1-yl)pyridine Complex |
Description | The solution-phase spin-crossover temperature in iron(II)/4-alkylsulfanyl-2,6-di{pyrazol-1-yl}pyridine complexes is influenced by the conformation of the SMe, SiPr or StBu alkylsulfanyl substituents. . |
Type Of Material | Database/Collection of data |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | None yet. |
URL | http://archive.researchdata.leeds.ac.uk/818/ |
Title | Data to support study of Iron and Silver Complexes of 4-(Imidazol-1-yl)-2,6-di(pyrazol-1-yl)pyridine (L), Including a [Fe3(mu-F)2F6L8]+ Assembly |
Description | Homoleptic iron and silver complexes of the potentially ditopic title ligand are reported, including an unusual Fe(III)3-fluoro cluster assembly. |
Type Of Material | Database/Collection of data |
Year Produced | 2020 |
Provided To Others? | Yes |
Impact | None yet. |
URL | http://archive.researchdata.leeds.ac.uk/738/ |
Title | Data to support study of Iron(II) Complexes of 2,4-Dipyrazolyl-1,3,5-Triazine Derivatives ? the Influence of Ligand Geometry on Metal Ion Spin State |
Description | Published dataset associated with the research paper doi: 10.1021/acs.inorgchem.7b00699 |
Type Of Material | Database/Collection of data |
Year Produced | 2017 |
Provided To Others? | Yes |
Impact | None yet. |
Title | Data to support study of Iron(II) Complexes of 4-(Alkyldisulfanyl)-2,6-di(pyrazolyl)pyridine Derivatives. Correlation of Spin-Crossover Cooperativity with Molecular Structure |
Description | [Fe(L1)2]X2 (1X2) form mixtures of solvated phases from acetone/diethyl ether, which transform to the same solvent-free material 1X2·sf upon mild heating. 1X2·sf exhibit abrupt spin-transitions with up to 38 K thermal hysteresis. |
Type Of Material | Database/Collection of data |
Year Produced | 2022 |
Provided To Others? | Yes |
Impact | None yet. |
URL | https://archive.researchdata.leeds.ac.uk/926/ |
Title | Data to support study of Iron/2,6-Di(pyrazol-1-yl)pyridine Derivatives with a Discotic Pattern of Alkyl or Alkynyl Substituents |
Description | Two compounds are isomorphous but show different spin-state behaviour on cooling. This may be influenced by the packing of alkyl vs alkynyl long chains in the solid state. |
Type Of Material | Database/Collection of data |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | None yet. |
URL | https://archive.researchdata.leeds.ac.uk/846/ |
Title | Data to support study of Modulating the Magnetic Properties of Copper(II)/Nitroxyl Heterospin Complexes by Suppression of the Jahn-Teller Distortion |
Description | Ferromagnetic coupling between the Cu and L1 ligand radical spins in [Cu(L)L1][BF4]2 (L1 = 2,6-bis{1-oxyl-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-2-yl}pyridine) is enhanced by a sterically bulky 'L' co-ligand. |
Type Of Material | Database/Collection of data |
Year Produced | 2020 |
Provided To Others? | Yes |
URL | https://archive.researchdata.leeds.ac.uk/686/ |
Title | Data to support study of Molecular Squares, Coordination Polymers and Mononuclear Complexes Supported by 2,4-Dipyrazolyl-6H-1,3,5-triazine and 4,6-Dipyrazolylpyrimidine Ligands |
Description | Published dataset associated with the research paper doi: 10.1039/c9dt04003j |
Type Of Material | Database/Collection of data |
Year Produced | 2019 |
Provided To Others? | Yes |
Impact | None yet. |
Title | Data to support study of Role of Symmetry Breaking in the Structural Trapping of Light-Induced Excited Spin States |
Description | Published dataset associated with research paper doi 10.1039/c7cc07990g |
Type Of Material | Database/Collection of data |
Year Produced | 2017 |
Provided To Others? | Yes |
Impact | Further collaboration with the Rennes group, funded by an RSC mobility grant |
Title | Data to support study of Spin States of Homochiral and Heterochiral Isomers of [Fe(PyBox)2]2+ Derivatives |
Description | Published dataset associated with the research paper doi: 10.1002/chem.201700820 |
Type Of Material | Database/Collection of data |
Year Produced | 2017 |
Provided To Others? | Yes |
Impact | None yet. |
Title | Data to support study of Structural transformations and spin-crossover in [FeL2]2+ salts (L = 4-{tertbutylsulfanyl}-2,6-di{pyrazol-1-yl}pyridine) - the influence of bulky ligand substituents |
Description | Desolvation of [FeL2][BF4]2·xMeNO2 occurs via an intermediate phase, exhibiting hysteretic spin-crossover (SCO) with a reverse step in its warming branch. Incomplete SCO in the final product phase reflects disorder of an L ligand. [FeL2][BF4]2·yMe2CO contains five complex cations per asymmetric unit, four of which undergo gradual SCO in at least two discrete steps. |
Type Of Material | Database/Collection of data |
Year Produced | 2020 |
Provided To Others? | Yes |
Impact | None yet. |
URL | http://archive.researchdata.leeds.ac.uk/764/ |
Title | Data to support study of Structure:Function Relationships for Thermal and Light-Induced Spin-Crossover in Isomorphous Molecular Materials |
Description | The complicated behaviour of a family of isostructural solvates under light-induced spin state trapping probably reflects the consequences of reorientation of the lattice solvent during the spin-transition process. |
Type Of Material | Database/Collection of data |
Year Produced | 2020 |
Provided To Others? | Yes |
URL | https://archive.researchdata.leeds.ac.uk/678/ |
Title | Data to support study of Supramolecular Iron Metallocubanes Exhibiting Site-Selective Thermal and Light-Induced Spin-Crossover |
Description | Published dataset associated with the research paper doi: 10.1021/jacs.9b08862 |
Type Of Material | Database/Collection of data |
Year Produced | 2019 |
Provided To Others? | No |
Impact | None yet. |
Title | Data to support study of The Number and Shape of Lattice Solvent Molecules Controls Spin-Crossover in an Isomorphous Series of Crystalline Solvate Salts |
Description | Crystals of [FeL2][BF4]2·nMeCN (L = N-(2,6-di{pyrazol-1-yl}pyrid-4-yl)acetamide; n = 1 or 2), [FeL2][ClO4]2·MeCN and [FeL2]X2·EtCN (X = BF4 or ClO4) are all isomorphous but exhibit a variety of spin state behaviours. |
Type Of Material | Database/Collection of data |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | None yet. |
URL | https://archive.researchdata.leeds.ac.uk/843/ |
Title | Data to support study of The Structures and Spin States of Iron(II) Complexes of Isomeric 2,6-Di(1,2,3-triazolyl)pyridine Ligands |
Description | Different isomers of the title ligands coordinate to iron(II) in monodentate or tridentate fashion, leading to complexes with a variety of spin state properties. |
Type Of Material | Database/Collection of data |
Year Produced | 2021 |
Provided To Others? | Yes |
Impact | None yet. |
URL | https://archive.researchdata.leeds.ac.uk/887/ |
Title | Data to support study of the Relationship Between Molecular Structure and Switching Temperature in a Library of Spin-Crossover Molecular Materials |
Description | A new approach to experimental structure:function relationships in spin-crossover molecular materials reveals how three crystal lattice types influence the temperature of a spin transition in different ways. |
Type Of Material | Database/Collection of data |
Year Produced | 2019 |
Provided To Others? | Yes |
Impact | None yet. |
URL | http://archive.researchdata.leeds.ac.uk/547/ |
Title | Data to support study of the speciation of homochiral and heterochiral diastereomers of homoleptic cobalt(II) and zinc(II) PyBox complexes |
Description | Heterochiral [M((R)-LiPr)((S)-LiPr)]2+ (M = Zn or Co) partially racemises by ligand redistribution in CD3CN, whereas [M((R)-LPh)((S)-LPh)]2+ does not. |
Type Of Material | Database/Collection of data |
Year Produced | 2018 |
Provided To Others? | Yes |
Description | City University of New York |
Organisation | City University of New York (CUNY) |
Country | United States |
Sector | Academic/University |
PI Contribution | Provision of samples for measurement, including deuterated samples. |
Collaborator Contribution | Powder neutron diffraction and magnetic measurements under pressure. |
Impact | One published paper, in Advanced Materials: doi 10.1002/adma.201807334 Multidisciplinary: chemical synthesis and solid state physics. |
Start Year | 2017 |
Description | EPFL Lausanne |
Organisation | Swiss Federal Institute of Technology in Lausanne (EPFL) |
Country | Switzerland |
Sector | Public |
PI Contribution | Providing crystallographic data to use in calculations. |
Collaborator Contribution | Performing solid state DFT calculations on materials from my laboratory. |
Impact | One paper so far: Journal of Materials Chemistry C: 10.1039/d0tc02174a |
Start Year | 2019 |
Description | ICMCB, CNRS, Bordeaux, France; photomagnetic measurements |
Organisation | National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS) |
Country | France |
Sector | Academic/University |
PI Contribution | Provision of samples |
Collaborator Contribution | Photomagnetic measurements |
Impact | Joint publications since 2006 (by doi): 10.1021/jacs.9b08862; 10.1039/c7cc07990g; 10.1016/j.poly.2017.01.029; 10.1002/chem.201406307; 10.1021/acs.inorgchem.5b00614; 10.1002/ejic.201201100; 10.1039/c2dt12122k; 10.1039/b907094j; 10.1039/b708971f; 10.1002/chem.200601312; 10.1039/b618480d; 10.1039/b601366j |
Description | International Tomography Centre, Novosibirsk, Russia |
Organisation | Russian Academy of Sciences |
Department | International Tomography Center |
Country | Russian Federation |
Sector | Public |
PI Contribution | Provision of samples |
Collaborator Contribution | Specialist EPR measurements |
Impact | Two published papers: Inorganic Chemistry: doi 10.1021/acs.inorgchem.8b01096 Inorganic Chemistry: doi 10.1021/acs.inorgchem.0c01345 A third paper in the Russian literature: doi 10.1007/s11172-017-1722-y. |
Start Year | 2016 |
Description | Osaka University |
Organisation | Osaka University |
Department | Graduate School of Science |
Country | Japan |
Sector | Academic/University |
PI Contribution | Provision of samples of our compounds. I also consult on some research projects in Osaka. |
Collaborator Contribution | Synchrotron powder diffraction measurements; magnetic measurements. |
Impact | Three published papers, in: Inorganic Chemistry: doi 10.1021/acs.inorgchem.8b02289 Inorganic Chemistry: doi 10.1021/acs.inorgchem.0c01345 Chemistry - a European Journal: doi 10.1002/chem.202000101 |
Start Year | 2017 |
Description | Technical University of Kaiserslautern |
Organisation | Technical University Kaiserslautern |
Country | Germany |
Sector | Academic/University |
PI Contribution | Provision of samples |
Collaborator Contribution | Moessbauer spectroscopy measurements |
Impact | One published paper, in JACS: doi 10.1021/jacs.9b08862 |
Start Year | 2018 |
Description | University of Bath, time resolved and high pressure crystallography |
Organisation | University of Bath |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Provision of crystalline samples for crystallographic study. |
Collaborator Contribution | Non-routine crystallography on our samples. |
Impact | Papers published so far by doi: 10.1002/chem.201704558; 10.1039/c7cc07990g; 10.3390/magnetochemistry2010009; 10.1002/chem.201406307; 10.1021/ic501402q. |
Start Year | 2013 |
Description | University of Oxford, time resolved crystallography |
Organisation | University of Oxford |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Provision of crystalline materials for study. |
Collaborator Contribution | Measurement of our samples by new time-resolved crystallography techniques. |
Impact | None yet. |
Start Year | 2013 |
Description | University of Rennes, photocrystallography |
Organisation | University of Rennes 1 |
Country | France |
Sector | Academic/University |
PI Contribution | Provision of samples. |
Collaborator Contribution | Photocrystallography. |
Impact | Two published papers: Chemical Communications: 10.1039/c7cc07990g Journal of Materials Chemistry C: 10.1039/d0tc02174a Some of this work was supported by an RSC travel grant to Dr R. Kulmaczewski (the PDRA employed on the grant). |
Start Year | 2016 |
Description | University of Warwick/Edinburgh/Bath, DF calculations |
Organisation | University of Warwick |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | The synthesis of model systems for comparison with computational predictions |
Collaborator Contribution | Calculations on compounds produced by our group. The collaboration ended when the collaborator Prof Rob Deeth retired. |
Impact | Two published papers: doi 10.1002/anie.201600165; 10.1002/chem.201704558 |
Start Year | 2013 |