Magnetic and Conducting Materials from Molecular Building Blocks

Research in the Pilkington group span topics in synthetic and structural inorganic chemistry with a focus on problems in molecular materials chemistry. The combined use of X-ray crystallography, EPR, magnetometry, and electrochemistry reflect the interdisciplinary nature of our research. Our aim is to define important synthetic challenges and tackle their solution with an arsenal of physical, chemical and spectroscopic data.

One-page summary of our research interests

1. Ligand Synthesis – Self-assembly is a powerful approach which involves the encoding of coordination information into a ligand, and then using a metal ion to interpret and use this information, according to its own coordination preferences, in order to organize the growth of large polynuclear metal ion arrays. These are of interest because they provide routes to novel magnetic materials, and in the context of a ‘bottom up’ approach to ‘devices’ based on molecules, an entry into the electronic, and perhaps magnetic, high technology arena of the future.

Our Strategy – Strategies to produce coordination complexes with large numbers of transition metal centers include direct synthesis from an ambidentate ligand, and methods which use the organizing ability of a metal ion and a ligand or a ligand precursor (e.g. template syntheses). The success of creating polynuclear complexes relies heavily on the use of synthetic organic techniques to produce new ligands and ligand precursors.

Structural and Magnetic Studies – Our interest in the creation of polynuclear complexes is driven in part by our interest in the solid state structures and magnetic properties of such systems. The design, synthesis and study of spin crossover compounds for possible applications in data storage and optical display devices is a major focus.

2. Dual Property Electronic and Magnetic Materials –
The search for molecular materials with interesting conducting, optical and/or magnetic properties presents a major challenge for synthetic chemists. Of particular interest are “hybrid” solids that combine two or more physical properties e.g. conductivity and magnetism not traditionally found in the same material.
Our Strategy – Our strategy involves the covalent attachment of metal ion binding groups to tetrathiafulvalene (TTF) derivatives. We then apply the principles of coordination chemistry for the design of new 1-D and higher dimensionality materials.

Research Group

More information

Current Group Members

Graduate students

Emma L. Gavey (Stares) (Ph.D student)
Zineb Ali (Ph.D student)
Amy Pham (MSc student)
Jeffrey Regier (MSc student)
Kevan Quinn (MSc student)

Undergraduate students

Majeda Al Hareri (BSc Chem)
Lucaz Wlodarek (BSc Neuro)
Marnie Edwardson (BSc Biochem)
Pilkington Group, June 2014

From Bottom left to right: Majeda Al Harari (NSERC undergraduate summer student); Dylan Johnston (undergrad. 3P98 student); Amy Pham (MSc student); (Marnie Edwardson – undergrad. 3P98 student); Emma Gavey (Ph.D student); John Hayward (Postdoc); Naomi Loussala (intern from Universite Paris-Sud Orsay, France;); Lukasz Wlodarek (undergrad. CHEM 2P98 student); Jeffrey Regier (MSc student).

Past Group Members

Postdocs

Dr.John J. Hayward
Dr. Qiang Wang
Dr. Prashanth Poddutoori
Dr. Nasser Hassan

Graduate students

Dr. Roger Gumbau Brisa
Dr. Roland Acha
Nicholas J. Hurley
Shari Venneri
Niloofar Zarrabi
Jian Wang

Undergraduate students

Dylan Johnston, Marco Haas, Rebecca Pearson, Justin Wilson, Peter Fenlon, Jeffrey Paul, John Folino, Brandon Djukic, Xiaoshu Wang, Keely Macnamara, Jennifer Anthony, Suchitra Guntur, Faviola Huapaya, Stephanie Stranges, Nancy Gadd, Zi(Byron) Lin, Jingy Cao, Chinmoyee Charkarborty, Valerie Bass, Brianna Slater.

Pilkington Group, July 2010

From Left to Right: Nicholas Hurley (Msc student), Dr. Qiang Wang (postdoc), Shari Venneri (MSc student), Justin Wilson (undergrad. summer student), Roger Gumbau Brisa (Ph.D student), Roland Acha (Ph.D. student), Dr. Melanie Pilkington (supervisor) and Niloofar Zarabbi (MSc student).

2016

66. Phosphorus(V)porphyrin-manganese(II)terpyridine conjugates: synthesis, spectroscopy and photooxidation studies on a SnO2 surface, P.K. Poddutoori, G.N. Lin, M. Pilkington, F.D’Souza and A. van der Est, Inorg. Chem., 2016, accepted for publication.
65. Encapsulation of a [Dy(OH2)8]2+ cation: magneto-optical and theoretical studies of a caged, emissive SMM, M. Al. Hareri, E.L. Gavey, J. Regier, Z. Ras Ali, L.D. Carlos, R.A.S. Ferreira and M. Pilkington, Chem. Commun., 2016, 52, 11335. (Front Cover)
64. Structural insights into the coordination chemistry and reactivity of a 3,3′-bis-imine-2,2′-bipyridine ligand, R. Gumbau-Brisa, J.J. Hayward, J.D. Wallis, J.M. Rawson and M. Pilkington, Cryst.Eng.Comm., 2016, 18, 1892. (Front Cover)
63. Employing Schiff-base macrocycles to probe the effect of ligand field on the relaxation dynamics of a family of Dy(III) SMM, E.L. Gavey and M. Pilkington, Polyhedron, 2016, 108, 122. (Invited Paper)
2015
62. Structural, magnetic and DFT studies on a charge transfer salt of a TTF-pyridyl-(1,5-diisopropyl)verdazyl diradical, cation, S. Venneri, J. Wilson, J.M. Rawson and M. Pilkington, ChemPlusChem. 2015, DOI: 10.1002/cplu.201500309. (Invited Cover)
61. Probing the structural changes accompanying a spin crossover transition in a chiral [Fe(II)(N3O2)(CN)2] macrocycle by X-ray crystallography. R. T. Acha and M. Pilkington, Cryst. Eng. Comm. 2015, 17, 8897. (Invited Paper)
60. Placing a crown on DyIII – a dual property LnIII complex displaying optical properties and SMM behaviour, E. L. Gavey, M. Al Hareri, J. Regier, L. D. Carlos, R. A. S. Ferreira, F. S. Razavi, J. M. Rawson and M. Pilkington, J. Mat. Chem. C. 2015, 3, 7738.
59. Methods and compounds for enhancing contrast in magnetic resonance imaging (MRI) E.L. Gavey and M. Pilkington, U.S. Provisional Patent Application No. 62/174,752 filed on June 12, 2015.
58. Molecular construction and photoinduced electron transfer studies of axially arranged supramolecular tetrathiafulvalene-aluminum(III)porphyrin-fullerene triads. P.K. Poddutoori, G. N. Lim, A. S. D. Sandanayaka, P. A. Karr, O. Ito, F. D’Souza, M. Pilkington and A. van der Est, Nanoscale, 2015, 7, 12151.
57. A family of unsymmetrical hydroxyl-substituted BEDT-TTF donors: syntheses, structures and preliminary thin film studies. Q. Wang, M. Zecchini, J. D. Wallis, Y. L. Wu, J.M. Rawson and M. Pilkington, RSC Advances, 2015, 5, 40205.
56. Stereochemistry for engineering spin crossover: structures and magnetic properties of a homochiral vs racemic [Fe(N3O2)(CN)2] complex.Q. Wang, S. Venneri, N. Zarrabi, H. Wang, C. Desplanches, J.-F. Letard, T. Seda and M. Pilkington, Dalton Trans., 2015, 44, 6711.
55. Coordination complexes of 15-membered pentadentate aza, oxoaza and thiaaza Schiff base macrocycles. “old ccmplexes offer new attractions”. E. L. Gavey and M. Pilkington, Coord. Chem. Rev., 2015, 296, 125.
54. Copper-promoted aerial oxidation of benzothiadiazines: Access to benzothiadiazine S-oxide heterocycles, E.R. Clark, J.J. Hayward, B.J. Leontowicz, M. Pilkington, and J. M. Rawson, Dalton Trans. 2015, 44, 2071.
53. 3,3′-Di(pyrazinamoyl)-2,2′-bipyridine: Rational ligand design for the self-assembly of a 1-D coordination polymer, N.J. Hurley, J.M. Rawson and M. Pilkington, Dalton Trans. 2015, 44, 1866.
52. Probing the reactivity of a 2,2′-bipyridyl-3,3′-bis-imine ligand by X-ray crystallography J. Wang, J. J. Hayward, R. Gumbau-Brisa, J. D. Wallis, H. Stoeckli-Evans and M. Pilkington, CrystEngComm., 2015, 17, 1159.

2014

51. Structural Aesthetics in Molecular Nanoscience: A Uniqjue Ni26 Cluster with a “Rabbit-Face’ Topology and a Discrete Ni18 ‘Molecular Chain’, A. A. Athanasopoulu, M. Pilkington, C. P. Raptopoulu, A. Escuer and T. C. Stamatatos, Chem. Commun., 2014, 95, 14908. (Front Cover)
50. A Structural Investigation of Novel Thiophene-Functionalized BEDT-TTF Donors for Applications as Organic Field-Effect Transistors,, Q. Wang, J. D. Wallis, Y. Wu and M. Pilkington, Cryst. Eng. Comm., 2014, 16, 7268.
49. Exploring the Coordination Chemistry of 3,3’-Di(picolinamoyl)-2,2’-bipyridine: One Ligand Multiple Nuclearities, N.J. Hurley, J. J. Hayward, J. M. Rawson, M. Murrie, and M. Pilkington, Inorg. Chem, 2014, 53, 8610.
48. Synthesis and Characterisation of First Row Transition Metal Complexes of Functionalized 1,2,4-Benzothiadiazines, E.R. Clark, M. U. Anwar, B.L. Leontowicz, Y. Beldjoudi, J, J. Hayward, W. K, Chan, E.L. Gavey, M. Pilkington, E. Zysman-Colman and J. M. Rawson, Dalton Trans., 2014, 43, 12996.
47. Transformation of a Ditopic Schiff-Base Nickel(II) Nitrate Complex into an Unsymmetrical Schiff Base Derivative by Partial Hydrolytic Degradation: Structural and Theoretical Studies, Q. Wang , Y. Liu , W. Gaoa, Z. Xua, Y. Lia, W. Lia, and M. Pilkington, Transition Metal Chemistry, 2014, 39, 613.
46. The First 1-D Cyanide-Bridged Complex Assembled from a Covalently Tethered [Co(N3O2)Cl(OH2)]22+ Macrocyclic Building Block, R. T. Acha, E. L. Gavey, J. Wang, J. M. Rawson and M. Pilkington, Polyhedron, 2014, 76, 122.
45. An Unusual Single Crystal-to-Single Crystal [2+2] Photocyclization Reaction of a TTF-Aryl-Nitrile Derivative, J. J. Hayward, R. Gumbau-Brisa, C. Clarke, A. Alberola, J. M. Rawson and M. Pilkington, Cryst. Eng. Comm., 2014, 16, 7268. (Invited Paper)
44. Slow Relaxation in the first Penta Aza Dy(III) Macrocyclic Complex, E.L. Gavey, Y. Beldjoudi, J.M. Rawson, T. Stamatatos and M. Pilkington, Chem. Commun., 2014, 50, 374.
43. Supramolecular Chains of High Nuclearity {MnIII25} Barrel-like Single Molecule Magnets, D.P. Giannopolous, A. Thuijs, M. Pilkington, W. Wernsdorfer, G. Christou, T. C. Stamatatos, Chem. Commun., 2014, 50, 779. (Front Cover)
42. Emissive Molecular Nanomagnets: Introducing Optical Properties in Triangular Oximato MnIII3 SMMs from the Deliberate Replacement of Simple Carboxylate Ligands with their Fluorescent Analogues, D. I. Alexandropoulos,A.M. Mowson,M. Pilkington,V. Bekiari,G. Christou and T. C. Stamatatos, Dalton Trans., 2014, 43. 1965. (Front Cover)
41. Saddling up Copper − New Twists on a Metallo-wheel, N. Zararabi, J. J. Hayward, W. Clegg and M. Pilkington, Dalton, Trans., 2014, 2352.

2008 – 2013

40. The use of the triptycene framework for observing O···C=O molecular interactions. A. Lari, E. Bresco, P. M. Pitak. S. J. Coles, P. Belser, A. Beyeler, M. Pillkington and J. D. Wallis, Cryst. Eng. Comm., 2011, 12, 6978. (Hot Article)
39. New chiral organosulfur donors related to bis(ethylenedithio)tetrathiafulvalene. S. Yang, A. C. Brooks, L. Martin, P. Day, M. Pilkington, W. Clegg, R.W. Harrington, L. Russo and J. D. Wallis, Tetrahedron, 2010, 66, 6977.
38. Spin-Spin Interactions in Porphyrin-Based Monoverdazyl Radical Hybrid Spin Systems. P. K. Poddutoori, A. Dion, S. J. Yang, M. Pilkington and J.D. Wallis, Inorg. Chem., 2010, 49, 3516.
37. Light Induced Hole Transfer in a Hypervalent Phosphorous (V) Octaethylporphyrin Bearing an Axially Linked BEDT-TTF. P. K. Poddutoori, A. Dion, S. Yang, M. Pilkington, J. D. Wallis and A. van der Est, J. Porphyrins and Phthalocyanines, 2010, 14, 178.
36. A Survey of Structure and Catalysis. Palladium(II), Platinum(II) and Indium(II) Complexes of 2-Phosphino-1-Dimethylamino Ferrocenes. C. Metallinos, J. Zaifman, L. Van Belle, L. Dodge and M. Pilkington, Organometallics, 2009, 28, 4534.
35. Rational Approaches to Organic Ferromagnets Based on Neutral Radicals Appended to Organosulfur Donors, A. Alberola and M. Pilkington, Current Organic Synthesis, 2009, 6, 66-78.
34. Three-Dimensional Bimetallic Octacyanidometalates [MIV-CN)4MnII(H2O)2}2.m33. {(4H2O]n (M=Nb, Mo, W): Synthesis, Single-Crystal X-ray Diffraction and Magnetism. M. J. Herrera, P. Franz, R. Podgajny, M. Pilkington, M. Biner, S. Decurtins, H. Stoeckli-Evans, A. Neels, R. Garde, Y. Dromzee, M. Julve, B. Sieclucka, K. Hashimoto, S. Okhoshi and M. Verdaguer, Comptes Rendus Chimie, 2008, 11, 1192.
33. Towards the Understanding of Magnetic Interactions within a Series of TTF-p-Conjugated Verdazyl Diradical Cation Systems – A Density Functional Theory Study. V. Polo, A. Alberola, J. Andres, J. Anthony and M. Pilkington, Phys. Chem. Chem. Phys, 2008, 10,857.

2002 – 2007

32. The Preparation of a Highly Reactive 3,3′-Disubstituted-2,2′-Bipyridine Ligand and its Rearrangement to a Novel Quaterpyridine Analogue. J. Wang, H. Stoeckli-Evans, S. Onions, J.K. Halfpenny, J. D. Wallis and M. Pilkington, J. Chem. Soc., Chem. Commun., 2007, 3628. (Invited Front Cover)
31. Synthesis and Characterization of a TTF-p-Verdazyl Radical – A New Building Block for Conducting and/or Magnetic Systems. M. Chahma, K. Macnamara, A. van der Est, A. Alberola, V. Polo and M. Pilkington, New J. Chem., 2007, 31, 1973.
30. The Preparation and Coordination Complex of the First Imine Bridged TTF-Pyridine Donor Ligand. M. Chahma, N. Hassan, A. Alberola, H. Stoeckli-Evans and M. Pilkington, Inorg. Chem., 2007, 46,3807.
29. The Rational Design of a Covalently Tethered Dinuclear [MnII(N3O2)]2 Macrocyclic Building Block: Synthesis, Structure and Magnetic Properties. J. Wang, B. Slater, A. Alberola, H. Stoeckli-Evans,F. Razavi and M. Pilkington, Inorg. Chem. 2007, 46, 4763.
28. A Novel Dinuclear Tridentate Bipyridine Carboxamide Ligand and its Complexation to Copper(II): Synthesis, Structure and Magnetism. J. Wang, B. Djukic A. Alberola, F. Razaviand M. Pilkington, Inorg. Chem., 2007, 46, 8560.
27. Synthesis and Characterization of a New Family of Spin Bearing TTF Ligands, M. Chahma, X.-S. Wang, A. van der Est, M. Pilkington, J. Org. Chem, 2006, 7, 2750.
26. Organosulfur donor with hydroxy groups and its conducting salt: crystal structures and physical properties. S.-X. Liu, A. Neels, H. Stoeckli-Evans, M. Pilkington, J. D. Wallis, S. Decurtins, Polyhedron, 2004, 23, 1185.
25. Novel Cyano-Bridged MII9MV6 Molecular Clusters [MII = Mn, Co, Ni; MV = Mo, W]. F. Bonadio, J. Larionova, M. Gross, M. Biner, H. Stoeckli-Evans, S. Decurtins and M. Pilkington, Inorg. Syntheses; Ed. J.R. Shapely, 2004, Vol. 34, 156-160.
24. High Nuclearity Clusters and Aggregates with Paramagnetic Centres: Cyano and Oxalato Bridged Systems. M. Pilkington and S. Decurtins, Comprehensive Coordination Chemistry II. Elsevier Science Ltd; Ed. A.K. Powell, 2004, Vol. 6, Chapter 7, 177-229.
23. A Rational Approach for the Self-Assembly of Molecular Building Blocks in the Field of Molecule-Based Magnetism. M. Pilkington and S. Decurtins, Crystal Engineering in Materials Chemistry. Wiley-VCH, Weinheim, Germany; Ed. G. Desiraju. 2003, Chapter 7, 276-322.
22. The design and synthesis of a novel aza-substituted phthalocyanine with four peripheral diimine binding sites. J. Rusanova, S. Decurtins and M. Pilkington, J. Chem. Soc., Chem. Commun., 2002, 19, 2236.
21. The facile synthesis of novel functionalized bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)derivatives. S.- X. Liu, S. Dolder, M. Pilkington and S. Decurtins, J. Org. Chem., 2002, 67, 3160.
20. The coordination chemistry of 3,3’-diamino-2,2’-bipyridine and its dication- exploring the role of the amino groups by X-ray crystallography. C. R. Rice,S. Onions,N. Vidal,J. D. Wallis,M.-C. Senna,M. Pilkington and H. Stoeckli-Evans, Eur. J. Inorg. Chem., 2002,8, 1985.
19. New carbon-carbon bond forming reactions of cyclic sulfate esters and cyclic sulfamidates. M. K. Pound, D. L. Davies, M. Pilkington, M. M. de Pina Vaz Sousa and J. D. Wallis, Tet. Lett.,2002, 43(10), 1915.
18. 2,2,2-Tris(cyclohexyloxy)-4,5-(2’,2’’-biphenylo)-1,3,2-dioxaphospholene. P. G. Jones, A. J. Kirby, M. Pilkington. Acta Cryst., 2002, E58(3), 268.

1996 – 2001

17. The exploitation of versatile building blocks for the self-assembly of novel molecular magnets. M. Pilkington, M. Gross, P. Franz, M. Biner, S. Decurtins, H. Stoeckli-Evans and A. Neels, J. Solid State Chem., 2001, 159(2), 262.
16. The utilization of classical spin monte carlo methods to stimulate magnetic behaviour of extended three-dimensional cubic networks incorporating M(II) ions with an S = 5/2 ground state spin. E. Boullant, J. Cano, Y. Journaux, S. Decurtins, M. Gross and M. Pilkington, Inorg. Chem., 2001, 40(16), 3900.
15. The design and synthesis of versatile molecular building blocks: working towards the controlled self-assembly of novel functional materials. M. Pilkington and S. Decurtins, Chimia, 2001, 55(12), 1014.
14. Functionalised organosulfur donor molecules: synthesis of racemic hydroxymethyl-, alkoxymethyl- and dialkoxymethylbis(ethylenedithio) tetrathiafulvalenes. N. Saygili, R.J. Brown, P. Day, R. Hoelzl, P. Kathirgamanathan, E. R. Mageean, T. Ozturk, M. Pilkington, M. M. B. Qayyum, S. S. Turner, L. Vorwerg and J. D. Wallis, Tetrahedron, 2001, 57(23), 5015.
13. Novel organosulfur donors containing hydroxy functionalities: synthesis of bis[2,2-bis(hydroxymethyl)propane-1,3-diyldithio)tetrathiafulvalene and related materials. T. Ozturk, N. Saygili, S. Ozkara, M. Pilkington, C. R. Rice, D. A. Tranter, F. Turksy and J. D. Wallis, J. Chem. Soc., Perkin Trans. 1, 2001, 4, 407.
12. Molecular distortions in crystalline 2-phenylethynylbenzoic acid. L. D. Hall, G. Orpen, M. Pilkington, J. D. Wallis, J. Chem. Cryst., 2001, 32(2), 97.
11. Oxalate–based 2D and 3D magnets. M. Pilkington and S. Decurtins, Magnetism from Molecules to Materials II, 2001, 338-356; Wiley-VCH, Weinheim, Germany; Eds. J. S. Miller and M. Drillon.
10. High-Spin molecules. A novel cyano-bridged Mn9IIMo6V molecular cluster with an S = 51/2 ground state and ferromagnetic intercluster ordering at low temperature. J. Larionova, M. Gross, M. Pilkington, H-P. Andres, H. Steockli-Evans, H.-U. Güdel and S. Decurtins. Angew. Chem. Int. Ed, 2000, 39(9), 1605.
9. Molecular-based magnetism in high-spin molecular clusters and three-dimensional networks based on cyanometalate building blocks. M. Pilkington, S. Decurtins. Chimia, 2000, 54(10), 593.
8. Synthesis and reactivity of tethered h1:h6-(phosphinoarene)ruthenium dichlorides. B. Therrien, T. R. Ward, M. Pilkington, C. Hoffmann, Organometallics, 1998, 17(3), 330.
7. New precursors for preparing organic conducting materials: synthesis of (R)-(hydroxymethyl)bis(ethylenedithio)tetrathiafulvalene, and the ring expansion of a cyclic sulfate ester. F. Leurquin, T. Ozturk, M. Pilkington and J. D. Wallis, J. Chem. Soc., Perkin Trans. 1, 1997,21, 3173.
6. 4,4’-Dinitro-2,2’-bipyridine. J. Hauser, M. Pilkington, C. Hoffmann, S. Capelli and H.-B. Bürgi., Acta Cryst., 1997, C53(11), 1719.
5. Geometry distorting intramolecular interactions to an alkyne group in 1-(2-aminophenyl)-2-(2-nitrophenyl)ethyne: a joint experimental-theoretical study. M. Pilkington, J. D. Wallis, G. Smith and J. A. K Howard, J. Chem. Soc., Perkin Trans. 2, 1996, 9, 1849.

1993 – 1995

4. An alkyne group with a pair of hydrogen bonds: the crystal structure of 2,2’-ethynylenedibenzeneboronic acid at 122 K. M. Pilkington, J. D. Wallis and S. Larsen, J. Chem. Soc., Chem. Commun., 1995, 15, 1499.
3. Attractive interactions between an alkyne group and two carbonyl oxygen atoms: the crystal and molecular structure of 2,2’-ethynylenedibenzoic acid at 150 K. M. Pilkington, S. Tayip, J. D. Wallis, J. Chem. Soc. Perkin. Trans 2., 1994, 12, 2481.
2. Methyl DL-3-benzyl-2,2-dioxo-1,2,3-oxathiazolidine-4-carboxylate – an intermediate for amino acid synthesis. P. Gritsonie, M. Pilkington and J. D. Wallis. Acta Cryst., 1994, C50(5), 763-765.
1. Synthesis and stability of the cyclic sulfamidate of N-trityl-L-serine methyl ester. M. Pilkington and J. D. Wallis, J. Chem. Soc., Chem. Commun., 1993, 24, 1857.

• CHEM 1P00 – Introductory Chemistry
• CHEM 2P32 – Principles of Inorganic Chemistry
• CHEM 3P98 – Undergraduate Research Project
• CHEM 5P34/4P34 – Structure Determination by X-ray Crystallography
• CHEM 5P33 – Supramolecular Chemistry