Department of Medicinal and Biological Chemistry

A. Alan Pinkerton, Ph.D.

Photo of Dr. Pinkerton

Professor

419.530.7902 Phone
BO 2024
a.pinkerton@utoledo.edu

Education

Graduate,1966 Royal Institute of Chemistry, Brighton Polytechnic (England)
Ph.D., 1971 University of Alberta (Canada)
Postdoctoral Fellow, 1971-72 University of Sussex (England)
1972-74 Universite de Lausanne (Switzerland)    
1974-76, Chercheur invite Faculte des Sciences, Universite de Nice (France)
Premier Assistant, 1976-78 Universite de Lausanne (Switzerland)
Maitre Assistant/Privat Docent, 1978-84 Universite de Lausanne (Switzerland)

X-Ray crystallography. Molecular structure determination, experimental electron densities, experimental electrostatic potentials of element chemistry.

Research Interests

Lanthanides and actinides. Synthetic routes have been developed to unusual lanthanide and actinide complexes with sulfur donor ligands containing phosphorus. The softness of the donor atoms enhances the covalent contribution to bonding to these hard metal ions. The complexes have been characterized by single crystal X-ray diffraction in the solid state and by NMR in solution. The observation of nuclear spin-spin coupling to 89-Y and through UO(2++) has been interpreted in terms of both sigma and pi contributions to the bonding. Hyperfine interactions have been derived from the NMR spectra (see below) of the paramagnetic complexes, which give information on electron-spin delocalization.

The work is currently being expanded to other sulfur donors, to other oxidation states of the lanthanides and actinides, and to organometallic compounds. The object of this study is to prepare new compounds in order to determine the influence of soft donor ligands on the stability and reactivity of the various oxidation states and of the organometallics, and to further characterize their bonding. The tools used will be X-ray diffraction, and solution and solid state NMR. Theoretical calculations are being carried out to characterize the orbitals involved in bonding and the mechanism for the transfer of spin to the ligands (hyperfine interactions).

Nuclear magnetic resonance. Our interest in NMR focuses on three major topics: i) Diamagnetic complexes in solution exhibit spin-spin coupling between 31-P and some metal nuclei, which gives us information about the intervening bonds. In other cases we are able to observe coupling between different phosphorous nuclei through the metal center which provides another bonding parameter; ii) Many lanthanide and actinide ions have unpaired f-electrons and are thus paramagnetic. We have developed methods to interpret the drastic effects these ions have on the NMR spectra of ligands. We thus obtain information concerning solution structures and a measure of spin delocalization expressed as the hyperfine coupling constant; iii) With the information available from solution NMR and solid state X-ray studies, we are now investigating NMR properties of these complexes in the solid in order to have an experimental link between solid state structures and those in solution.

X-Ray crystallography. The use of X-ray crystallography to solve chemical problems is well developed. We have structural interests in a wide variety of molecules. These studies are carried out on compounds we have prepared ourselves (see above), and on compounds prepared by other groups either within this department or as part of an international collaboration. Current studies involve small organic and organometallic molecules, drug structures, models of drug receptor sites, and natural products. Using a combination of X-ray diffraction and neutron diffraction we are able to determine charge density in the bonding region of small molecules. Current studies examine the metal-metal bond in a series of related organometallics, the deformation of pi-electron density due to pyramidalized sp2 carbon in a series of organic molecules, and the charge-density distribution in high energy (explosive) molecules. The study will be extended to map the electrostatic potential around molecules.

Representative Publications

  1. Dollimore, D., A. Martin and A.A. Pinkerton. (1996) A study of the thermal decomposition of biguanidinium diperchlorate using thermogravimetry and mass spectroscopy. Thermochim. Acta 285, 109-117.
     
  2. Pinkerton, A.A., C. leDrian and P. Vogel. (1996) Torturing the 7-oxabicyclo[2.2.1]heptane skeleton with an oxetane ring: structure of 4,7-dioxatricyclo[3.2.1.0-2,4]octane at 190 K. Acta Crystallogr. C52, 2927-2929.
     
  3. Guidi, A., V. Theurillat-Moritz, P. Vogel and A.A. Pinkerton. (1996) Enantiomerically pure Diels-Alder adducts of maleic anhydride to furfural acetals through thermodynamic control. Single crystal and molecular structure of (1S,4R,4'S,5'S)-1-(4',5'-dimethyldioxolan-2'-yl)-5,6-dimethylidenei-7-oxabicyclo[2.2.1]hept-2-ene. Tetrahed. Asymm. 7, 3153-3162.
       
  4. Li, J., K.V. Katti, A.A. Pinkerton, H. Nar and R.G.Cavell. (1996) Synthesis and characterization of phosphinimine-substituted trifluoro- or trichloro-p-benzoquinones and their cationic Rh(I) complexes. The crystal and molecular structure of 3,5,6-trichloro-2-(triphenylphosphinimino)-p-benzoquinone. Can. J. Chem. 74, 2378-2385.
     
  5. Pinkerton, A.A. and A. Martin. (1996) Charge densities and electrostatic potentials for energetic materials. Mater. Res. Soc. Symp. Proc. 418, 49-54.
     
  6. Martin, A., A.A. Pinkerton and A. Schiemann. (1996) Energetic materials: the biguanidinium nitrates. (1996) Acta Crystallogr., Sect. C: Cryst. Struct. Commun. C52, 966-970.
     
  7. Martin, A. and A.A. Pinkerton. (1996) Two energetic ionic materials: the biguanidinium perchlorates. Acta Crystallogr. Sect C: Cryst. Struct. Commun. C52, 1048-1052.
     
  8. Li, J., A.A. Pinkerton, D.C. Finnen, M. Kummer, A. Martin, F. Wiesemann and R.G. Cavell. (1996) Multifunctional ligands. Phosphinimine-substituted cyanofluoroaromatics including x-ray molecular structures of three representative ligands: 4,6-(CN)2C6F2-1,3-(N:PPh3)2, 4,6-(CN)2C6F3-1,3-(N:PPh2Me)2 and 4,6-(CN)2C6F2-1-(N:PPh3)-3-(N:PPh2Me).Formation of L complexes Rhodium(I). Inorg. Chem. 35, 5684-5692.
     
  9. Pinkerton, A.A., and A. Martin. Charge densities and electrostatic potentials for energetic materials. Mat. Res. Soc. Symp. Proc.418: 49-53, 1996.
     
  10. Martin, A., A.A. Pinkerton and A. Schiemann: Energetic materials. The biguanidinium nitrates. Acta Crystallogr. C52: 966-970, 1996.
     
  11. Martin, A. and A.A. Pinkerton. Two energetic ionic materials: the biguanidinium perchlorates. Acta. Crystallogr. C52: 1048-1052, 1996..
     
  12. Li, J., A.A. Pinkerton, D.C Finnen, m. Kummer, A. Martin, F. Wiesemann and R.G. Cavell. Multifunctional ligands. Phosphinimine-substituted cyanofluoroaromatics including x-ray molecular structures of three representative ligands 4,6-(CN)2C6F2-1,3-(N = PPh3) 2, ,4,6-(CN)2C6F2-1,3-(N = PPh3Me) 2 and 4,6-(CN)2C6F2-1-(N = PPh3)-3-( = PPh2Me) 2 Formation of Rhodium(I) complexes. Inorg. Chem. 35: 5684-5692, 1996.
     
  13. Dollimore, D., A. Martin and A.A. Pinkerton. A study of the thermal decomposition of biguanidinium dipherchlorate using thermogravimetry and mass spectroscopy. Thermochim. Acta 285: 109-117, 1996.
     
  14. Pinkerton, A.A. C. deDrian, and P. Vogel. Torturing the 7-oxabicyclo[2.2.1]heptane skeleton with an oxetane ring: structure of 4,7-dioxatricyclo[3.2.102,4]octane at 190 K. Acta Crystallogr. C62: 2927-2929.
     
  15. Li, J., K.V. Katti, A.A. Pinkerton, H. Nar and R.G. Cavell. Synthesis and characterization of phosphinimine-substituted trifluoro- or trichloro-p-benzoquinones and their cationic rh(I) complexes. The crystal and molecular structure of 3,5,6-trichloro-2 (triphenyphosphinimino)-p-benzo-quinone. Can. J. Chem. 74: 2378-2385, 1996.
     
  16. Guidi, A., V. Theurillat-Moritz, P. Vogel and A.A. Pinkerton. Enantiomerically pure Diels-Alder adducts of maleic anhydride to furfural acetals through thermodynamic control. Single crystal and molecular structure of (1S,-4R,r'S,5'S)-1-(4',5'-dimethyldioxolan-2'yl)-56-dimethylidene-7-oxabicyclo-[2,2.1]hept-2-ene. Tetrahed, Asymm 7: 3153-3162, 1996.
     
  17. Martin, A., A.A. Pinkerton, RD**. Gilardi and J.C. Bottaro. Energetic materials - the preparation and structural characterization of three biguanidinium dinitramides. Acta Crystallogr B53: 504-512, 1997.
     
  18. Pinkerton, A.A., A. Martin, A.P. Marchand, and A. Devasagayaraj. Intermolecular [2 + 2} photocyclization of ethyl 5-oxo-1a,2,5,5a,6,6ahexahydro-2,6-methano-2aH-indeno-[5,6-b]oxirene-2a-carboxylate. J. Chem. Crystallogr. 27: 701-705, 1997.
     
  19. Martin, A., A.A. Pinkerton, R.D. Gilardi and J. C. Bottaro. Energetic materials: the preparation and structural characterization of three biguanidinium dinitramides. Acta Crystallogr., Sect. B: Struct. Sci. B853: 50,512, 1997.
     
  20. Finnen, D.C. and A.A. Pinkerton. The chelating agent N,N,N',N'',N''',N''''-triethylenetraminehexacetic acid (TTHA). Acta Crystallogr., Sect. C: Cryst. Struct. Commun. C53: 1455-1457, 1997.
     
  21. Gano, J.E., C. Kluwe, K. Kirschbaum, A.A. Pinkerton, P. Sekheer, E Skrzypczak-Junkun, G. Subramaamaniam and D. Lenoir. (E)-2,2,5,5-tetramethyl-3,4-diphenylhex-3-ene, C22H28. Acta Crystallogr. Sect. C: Cryst. Struct. Commun., C53: 1723-1725, 1997.
     
  22. Pinkerton, A.A., F.P. Ahlers, H.F. Greiwing and B. Krebs. Dithiophosphinate complexes of the UO22+ ion containing a coordinated water molecule - solid sate structures and stereochemical regidity in solution. Inorg. Chim. Acta 257: 77-81, 1997.
     
  23. Kirschbaum, K., A. Martin and A.A. Pinkerton. Contamination in charge-coupled device area-detector data. J. Appl. Crstallogr. 30: 514-516, 1997.
     
  24. Pinkerton, A.A., A. Martin, A.P. Marchand and A. Devasagayaraj. Intermolecular photocyclization of ethyl5-oxo-1a,2,5,5a,6,6a-hexahydro-2,6,6a-hexahydro-2,6-methano-2aH-indenooxiene-2a-carboxylate. J. Chem. Crystallogr 27: 701-705, 1997.
     
  25. Mosimann, H., P. Vogel, A.A. Pinkerton and K. Kirschbaum. Highly stereoselective synthesis of perhydro-8a-(hydroxymethyl)phenathrene-1,2,4,5,7,8-hexol and derivatives. J. Org. Chem. 62: 3002-3007, 1997.
     
  26. Pearson, A.J., I.B. Neagu, A.A. Pinkerton, K. Kirschbaum and M.J. Hardy. Studies on lateral stereocontrol using the ally-molybdenum system. Organometallics 16: 4346-4354, 1997.
     
  27. Martin, A. and A.A. Pinkerton. Charge density studies using CCD detectors: oxallic acid at 100  K revisited. Acta Crystallogr., Sect B: Struct. Sci B54: 471-477, 1998.
     
  28. Iversen, B.B., F.K. Larsen, A.A. Pinkerton, A. Martin, A. Darovsky and P.A. Reynolds. Characterization of actinide bonding I Th(S2Pme2)4 by Synchrotron X-ray diffraction. Inorg. Chem. 37: 4559-4566, 1998.
     
  29. Bosing, M., O. Conrad, B. Hommerich, K. Kirschbaum, E. Kovari, B. Krebs, A.A. Pinkerton and W. Steinforth. Complexes of niobium and tantalum with chloride, sulfide and oxide ligands: synthesis and crystal structure of the (tetrachloro)bis- 2-disulfidodisfulfido bismetallates 2-and 2- as their tetraphenylphosphonium salts. Inorg. Chim. Acta 274: 251-256, 1998.
     
  30. Pearson, A.J., A. Alimardanov, A.A. Pinkerton and D.A. Parrish. Intramolecular coupling reactions of allylic thioesters with diene iron tricarbonyl systems. J. Org. Chem. 63: 6610-6618, 1998.
     
  31. Pearson, A.J., A. Alimardanov, A.A. Pinkerton, D.A. Fourchard and K. Kirschbaum. Stereocontrolled cyclization of unactivated alkene onto cationic dienyl iron tricarbonyl systems. Tetrahedron Lett. 39; 5919-5922, 1998.
     
  32. Hardie, M.J., K. Kirschbau, A. Martin and A.A. Pinkerton. An open flow helium cryostat for x-ray diffraction. J. Appl. Cryst. 31: 815-817, 1998.
     
  33. Bosing, M., O. Conrad, B. Hommerich, K. Kirschbaum, E. Kovari, B. Krebs, A.A. Pinkerton and W. Steinforth. Quaternary complexes of tantalum and niobium with chloride-, sulfide- and oxide ligands: synthesis and crystal structure of (tetrachloro)bis(disulfido) - (-2:2-disulfido)(oxo-)bismetallates [Cl2(S2)Ta(-0)(-S2)Ta(S2)Cl2]2- and [Cl2(S2)Nb(-0)(-S2)Nb(S2)Cl2]2- as their tetraphenylphosphonium salts. Inorg. Chim. Acta 274: 251-256, 1998.
     
  34. Martin, A.; and Pinkerton, A.A.; Charge Density Studies Using CCD Detectors - Oxalic Acid at 100 K Revisited. Acta Crystallogr., 1998, B54, 471-478.
     
  35. Pearson, A.J.; Alimardanov, A.; Pinkerton, A.A.; Fouchard, D.M.; and Kirschbaum, K.; Stereocontrolled Cyclization of Unactivated Alkene onto Cationic Dienyl Iron Tricarbonyl Systems. Tetrahed. Let., 1998, 39, 5919-5922.
     
  36. Iversen, B.B.; Larsen, F.K.; Pinkerton, A.A.; Martin, A.; Darovsky, A.; and Reynolds, P.A.; Characterization of Actinide Bonding in Th(S2PMe2)4 by Synchrotron X-Ray Diffraction. Inorg. Chem., 1998, 37, 4559-4566.
     
  37. Hardie, M.J., Kirschbaum,. K., Martin, A; and Pinkerton, A.A. An Open Flow Helium Cryostat for X-ray Diffraction.. J. Appl. Cryst., 1998, 31, 815-817.
     
  38. Pearson, A.J.; Alimardanov, A.; Pinkerton, A.A.; and Parrish, D.A; Intramolecular Coupling Reactions of Allylic Thioethers with Diene Iron Tricarbonyl Systems.J. Org. Chem., 1998, 63, 6610-6618.
     
  39. Pinkerton, A.A.; Burckel, P.M.; Marchand, A.P.; and Dong, E.Z.; Structure of 1,2,3,4,9,9-Hexachloro-6,7-tetrahydro-1,4-methanonaphthalene: A Facially Different-iated, Annulated 1,3-Cyclohexadiene.J. Chem. Crystallogr., 1998, 28, 913-917.
     
  40. Dutta, S.K.; Samanta, S.; Kumar, S.B.; Han, O.H.; Burckel, P.; Pinkerton, A.A.; Mixed Oxidation Divanadium(IV,V) Compound with Ligand Asymmetry: Electronic and Molecular Structure in Solution and in the Solid State.and Chaudhury M.; Inorg. Chem., 1999, 38, 1982-1988.
     
  41. Pinkerton, A.A., A Variable Temperature X-ray Diffraction Study of 4,7-Dioxatricyclo[3.2.1.03,6]octane and Characterization of the High Temperature (> 268 K) Plastic Crystalline Phase. Mol. Cryst. Liq. Cryst., 1999, 325, 251-257.
     
  42. Tanbug, R; Kirschbaum, K.; and Pinkerton, A.A.; Energetic Materials: The Preparation and Structural Characterization of Melaminium Dinitramide and Melaminium Nitrate. J. Chem. Crystallogr., 1999, 29, 45-55.
     
  43. Kirschbaum, K.; Martin, A.; Parrish, D.A.; and Pinkerton, A.A Cooperative Jahn-Teller Induced Phase Transition of TbVO4: Single Crystal Structure Analysis of the Tetragonal High Temperature Phase and the Twinned Orthorhombic Phase below 33 K., J. Phys. Condens. Mat.,1999, 11, 4483-4490.
     
  44. Hu, Z.; Hardie, M.J.;P Burckel, P.; Pinkerton, A.A.; and Erhardt, P.W Conversion of 2,4-Dihydroxybenzaldehyde to 2-Benzoyloxy-4-hydroxybenzaldehyde and their Structural Characterization. J. Chem. Crystallogr., 1999, 29, 185-191.
     
  45. Hanson, B.L; Martin, A.; Harp, J.M.; Bunick, C.G.; Parrish, D.A.; Kirschbaum, K.; Bunick, G.J.; and Pinkerton, A.A.; Use of an Open Flow Helium Cryostat for Macromolecular Cryocrystallography. J. Appl. Cryst., 1999, 32, 814-820.
     
  46. Iversen, B.B.; Larsen, F.K.; Pinkerton, A.A.; Martin, A.; Darovsky, A.; and Reynolds, P.A.; Accurate Charge Densities in Days — Use of Synchrotrons, Image Plates and Very Low Temperatures. Acta Crystallogr.,1999, B55, 363-374.
     
  47. Hasche, S.; Mock, C.; Otto, J.; Schweppe, F.; Kirschbaum, K.; Krebs, B.; and Pinkerton, A.A Polymeric structures containing self-assembled Li-dioxane networks; syntheses and crystal structures of [{Li(dioxane)2.5TaCl4S}n]·n/2 dioxane and [{Li2(dioxane)3Cl}n][TaCl6]n. Inorg. Chim. Acta, 2000, 298, 9-15.
     
  48. Pinkerton, A.A Charge Density Data from CCD Detectors.in "Electron, Spin and Momentum Densities and Chemical Reactivity," P.G. Mezey and B. Robertson, eds., Klewer, 2000.
     
  49. Erhardt, P.W.; Klis, W.A.;Nagy, P.I.; Kirschbaum, K.; Wu, N.; Martin, A.; and Pinkerton, A.A. 2-Phenylglycerol: Crystal Structure and Conformational Considerations Pertaining to Formation of Its Related Oxetane J. Chem. Crystallogr., in press.
     
  50. Formation of Homosoric Columns in the Solid State from Acceptor-Donor-Acceptor Triads: An Example of Stacking Controlled by Molecular Topology.Pearson, A.J.; Gelormini, A.M.; Kirschbaum, K.; and Pinkerton, A.A.; J. Chem. Crystallogr., submitted for publication.
     
  51. Hardie, M.J.; Martin, A.; and Pinkerton, A.A. Anisotropic Thermal Expansion of Potassium Dinitramide - A Variable Temperature Crystallographic Study. Chem. Mater., submitted for publication.
     
  52. Linear Tricobalt Compounds with Di-(2-pyridyl)amide (dpa) Ligands: Temperature Dependence of the Structural and Magnetic Properties of Symmetrical and Unsymmetrical Forms of Co3(dpa)4Cl2 in the Solid State, submitted for publication.
     
  53. Clérac, R.; Cotton, F.A.; Daniels, L.M.; Dunbar, K.R.; Kirschbaum, K.; Murillo, C.A.; Pinkerton, A.A.; Schultz, A.J. and Wang, X., J. Am. Chem. Soc., submitted for publication.
Last Updated: 6/26/15