Abstract
Spin density distributions in molecular compounds containing unpaired electrons have been studied by polarized neutron diffraction (PND). The spin density distributions provide a unique perspective of the magnetic properties of the compounds. The background and fundamentals of polarized neutron diffraction are summarized in this review, followed by examples of applications in inorganic and organic chemistry. Spin densities in several compounds that are obtained by polarized neutron diffraction are highlighted. Spin densities in single molecular magnet [Fe8O2(OH)12(tacn)6]8+ and cyano-bridged K2[Mn(H2O)2]3[Mo(CN)7]2·6H2O demonstrate how to obtain magnetic interaction in the complexes by PND. PND studies of Ru(acac)3, containing one single unpaired electron, show small spin densities in this complex. Finally the use of PND in studying nitronyl nitroxide radicals is given. Our goal in this review is to illustrate how PND functions and how it serves as a sensitive tool in directly probing spin density in molecules.
Similar content being viewed by others
References
Becini A, Gatteschi D. EPR of Exchange Coupled Systems. Berlin: Springer-Verlag, 1990
Willett R D, Gatteschi D, Kahn O. Magneto-Structural Correlations in Exchange Coupled Systems. Dordrecht: Reidel, 1985. 207–240
Gatteschi D J. Physical techniques for the investigation of molecular magnetic clusters. J Phys Chem B, 2000, 104: 9780–9787
Sharp R R, Paramagnetic NMR. Nucl Mag Res, 2005, 34: 553–596
Bertini I, Luchinat C, Parigi G, Pierattelli R. Perspectives in paramagnetic NMR of metalloproteins. Dalton Trans, 2008, 3782–3790
Hoffman B M. ENDOR of metalloenzymes. Acc Chem Res, 2003, 36: 522–529
Chen D F, Liu Y T, Gou C, Ye C T. Development of neutron scattering on 60 MW research reactor in CIAE. Physica B, 2006, 385–386: 966–967
Wei J, Chen H, Chen Y, Chen Y, Chi Y, Deng C, Dong H, Dong L, Fang S, Feng J, Fu S, He L, He W, Heng Y, Huang K, Jia X, Kang W, Kong X, Li J, Liang T, Lin G, Liu Z, Ouyang H, Qin Q, Qu H, Shi C, Sun H, Tang J, Tao J, Wang C, Wang F, Wang D, Wang Q, Wang S, Wei T, Xi J, Xu T, Xu Z, Yin W, Yin X, Zhang J, Zhang Z, Zhang Z, Zhou M, Zhu T. China Spallation Neutron Source: Design, R&D, and outlook. Nucl Instrum Meth A, 2009, 600: 10–13
Wilson C C. Single Crystal Neutron Diffraction from Molecular Materials. Singapore: World Scientific, 2000
Larese J Z. Neutron Scattering. In: Scott R A, Lukehart C M, eds. Applications of Physical Methods to Inorganic and Bioinorganic Chemistry. Chichester, UK: Wiley, 2007. 291–313
Long G J. Neutron Diffraction. In: McCleverty J A, Meyer T J, eds. Comprehensive Coordination Chemistry II. Amsterdam: Elsevier, 2003. 83–90
Dianoux A-J, Lander G. Neutron Data Booklet, 2nd ed. Philadelphia: Old City Publishing, Philadelphia, PA, USA, 2003
McIntyre G J, Lemee-Cailleau M H, Wilkinson C. High-speed neutron Laue diffraction comes of age. Physica B, 2006, 385–386: 1055–1058
Gukasov A, Goujon A, Meuriot J-L, Person C, Exil G, Koskas G. Super-6T2, a new position-sensitive detector polarized neutron diffractometer. Physica B, 2007, 397: 131–134
West C D, Farrar M B. Upgrading scientific capabilities at the high-flux isotope reactor. Physica B, 1997, 241–243: 46–47
Mason T E, Abernathy D, Anderson I, Ankner J, Egami T, Ehlers G, Ekkebus A, Granroth G, Hagen M, Herwig K, Hodges J, Hoffmann C, Horak C, Horton L, Klose F, Larese J, Mesecar A, Myles D, Neuefeind J, Ohl M, Tulk C, Wang X L, Zhao J. The Spallation Neutron Source in Oak Ridge: A powerful tool for materials research. Physica B, 2006, 385–386: 955–960
Meigo S-I, Ohi M, Kai T, Ono T, Ikezaki K, Haraguchi T, Fujimori H, Sakamoto S. Beam commissioning for neutron and muon facility at J-PARC. Nucl Instrum Meth A, 2009, 600: 41–43
Kennedy, S J. Construction of the neutron beam facility at Australia’s OPAL research reactor. Physica B, 2006, 385–386: 949–954
Schultz A J. Single-crystal time-of-flight neutron diffraction. Trans Am Cryst Assoc, 1993, 29: 29–41
Nathans R, Pigott M T, Shull C G. The magnetic structure of Fe3Al. J Phys Chem Solids, 1958, 6: 38–42
Lelievre-Berna E, Bourgeat-Lami E, Gibert Y, Kernavanois N, Locatelli J, Mary T, Pastrello G, Petukhov A, Pujol S, Rouques R, Thomas F, Thomas M, Tasset F. ILL polarized hot-neutron beam facility D3. Physica B, 2005, 356: 141–145
Courtois P, Hamelin B, Andersen K H. Production of copper and Heusler alloy Cu2MnAl mosaic single crystals for neutron monochromators. Nucl Instrum Meth A, 2004, 529: 157–161
Jones G L, Dias F, Collett B, Chen W C, Gentile T R, Piccoli P M B, Miller M E, Schultz A J, Yan H, Tong X, Snow W M, Lee W T, Hoffmann C, Thomison J. Test of a continuously polarized 3He neutron spin filter with NMR-based polarization inversion on a single-crystal diffractometer. Physica B, 2006, 385–386: 1131–1133
Hussey D S, Rich D R, Belov A S, Tong X, Yang H, Bailey C, Keith C D, Hartfield J, Hall G D R, Black T C, Snow W M, Gentile T R, Chen W C, Jones G L, Wildman E. Polarized 3He gas compression system using metastability-exchange optical pumping. Rev Sci Instrum 2005, 76: 053503
Cicognani G, ed. The Yellow Book 2008, Institut Laue-Langevin, France, 2008. 34–35
Spaldin N A. Magnetic Materials. Cambridge: University Press, 2003, 46
Shirane G, Shapiro S M, Transquada, J M. Neutron Scattering with a Triple-Axis Spectrometer: Basic Techniques. Cambridge, UK: Cambridge University Press, 2002
Schweizer J. Historical account of polarized neutrons in Grenoble. Physica B, 1999, 267–268: 9–20
Shull C G. Neutron diffraction. Adv Mater Res, 1967, 1: 29–50
Reynolds P A, Cable J W, Sobolev A N, Figgis B N. Structure, covalence and spin polarization in tris(acetylacetonato)ruthenium(III) studied by X-ray and polarized neutron diffraction. J Chem Soc Dalton Trans, 1998, 559–569
Press Release for the Nobel Prize in Physics 1994, Nobel Foundation, 1994
Nathans R, Shull C G, Shirane G, Andresen A. The use of polarized neutrons in determining the magnetic scattering by iron and nickel. Phys Chem Solids, 1959, 10: 138–146
Kahn O. Chemistry and physics of supramolecular magnetic materials. Acc Chem Res, 2000, 33: 647–657
Brown P J, Forsyth J B. The determination of beam polarization and flipping efficiency in polarized neutron diffractometry. Brit J Appl Phys, 1964, 15: 1529–1533
Brown P J, Forsyth J B, Mason R. Magnetization densities and electronic states in crystals. Proc. R. Soc. B, 1980, 290: 481–495
Schweizer J, Ressouche E. Neutron Scattering and Spin Densities in Free Radicals. In: Miller J S, Drillon M, eds. Magnetism Molecules to Materials. New York: Wiley-VCH, 2001. 325–355
Ressouche E. Investigating molecular magnetism with polarized neutrons. Physica B, 1999, 267–268: 27–36
Gillon B. Spin Distributions in Molecular Systems with Interacting Transition Metal Ions. In: Miller J S, Drillon M, eds. Magnetism Molecules to Materials. New York: Wiley-VCH, 2001. 357–378
Barnes L A, Chandler G S, Figgis B N. Orbital magnetization in tetrachlorocobaltate(2−) (CoCl 2−4 ) and phthalocyaninatocobalt from polarized neutron diffraction. Mol Phys, 1989, 68: 711–735
Matthewman J C, Thompson P, Brown P J. The Cambridge crystallography subroutine library. J Appl Cryst, 1982, 15: 167–173
Zheludev A, Bonnet, M, Delley B, Grand A, Ressouche E, Rey P, Subra R, Schweizer J. Spin density in a nitronyl nitroxide free radical. Polarized neutron diffraction investigation and ab initio calculations. J Am Chem Soc, 1994, 116: 2019–2027
Papoular R J, Gillon B. Maximum entropy reconstruction of spin density maps in crystals from polarized neutron diffraction data. Europhys Lett, 1990, 13: 429–434
Koritsanszky T S, Coppens P. Chemical applications of X-ray charge-density analysis. Chem Rev, 2001, 101: 1583–1627
Volkov A, Macchi P, Farrugia L J, Gatti C, Mallinson P, Richter T, Koritsanszky T. XD-2006. A Computer Program Package for Multipole Refinement, Topological Analysis of Charge Densities and Evaluation of Intermolecular Energies from Experimental and Theoretical Structure Factors. New York: Buffalo, 2006
Maruani J. Molecules in Physics, Chemistry and Biology. Dordrecht: Kluwer Academic Publisher, 1989. 111–147
Hong C S, Do Y. Canted ferromagnetism in a NiII chain with a single end-to-end azido bridge. Angew Chem Int Ed, 1999, 38: 193–195
Gillon B, Sangregorio C, Caneschi A, Gatteschi D, Sessoli R, Ressouche E, Pontillon Y. Experimental spin density in the high spin ground state of the Fe8pcl cluster. Inorg Chim Acta, 2007, 360: 3802–3806
Pontillon Y, Caneschi A, Gatteschi D, Sessoli R, Ressouche E, Schweizer J, Lelievere-Berna E. Magnetization density in an iron(III) magnetic cluster. A polarized neutron investigation. J Am Chem Soc, 1999, 121: 5342–5343
Gillon B, Goujon A, Willemin S, Larionova J, Desplanches C, Ruiz E, Andre G, Stride J. A, Guerin C. Neutron diffraction and theoretical DFT studies of two dimensional molecular-based magnet K2[Mn-(H2O)2]3[Mo(CN)7]2·6H2O. Inorg Chem, 2007, 46: 1090–1099
Larionova J, Kahn O, Gohlen S, Ouahab L, Clérac R. Structure, ferromagnetic ordering, anisotropy, and spin reorientation for the two-dimensional cyano-bridged bimetallic compound K2Mn3(H2O)6-[Mo(CN)7]2·6H2O. J Am Chem Soc, 1999, 121: 3349–3356
Figgis B N, Reynolds P A, Murray K S, Moubaraki B. The ground state in tris(acetylacetonato)ruthenium(III) from low-temperature single-crystal magnetic properties. Aust J Chem, 1998, 51: 229–234
Jarrett H S. Paramagnetic resonance in trivalent transition metal complexes. J Chem Phys, 1957, 27: 1298–1304
DeSimone R E. Electron paramagnetic resonance studies of low-spin d5 complexes. Trisbidentate complexes of iron(III), ruthenium(III), and osmium(III) with sulfur-donor ligands. J Am Chem Soc, 1973, 95: 6238–6244
Doddrell D M, Gregson A K. Carbon-13 NMR studies of some paramagnetic transition-metal acetylacetonates. Linewidth consideration. Chem Phys Lett, 1974, 29: 512–515
Waysbort D. The contributions of metal and ligand spin densities to the ligand dipolar relaxation in paramagnetic complexes. Chem Phys Chem, 1978, 82: 907–909
Doddrell D M, Pegg D T, Bendall M R, Gregson A K. Electron and nuclear spin relaxation in S = 1/2 paramagnetic transition-metal complexes. Aust J Chem, 1977, 30: 1635–1643
Doddrell D M, Pegg D T, Bendall M R, Gottlieb H P W, Gregson A K, Anker M. Carbon-13 spin-relaxation times in some paramagnetic transition-metal acetylacetonate complexes. Importance of ligand-centered relaxation. Chem Phys Lett, 1976, 39: 65–68
Eaton D R. The nuclear magnetic resonance of some paramagnetic transition metal acetylacetonates. J Am Chem Soc, 1965, 87: 3097–3102
Doddrell D M, Pegg D T, Bendall M R, Healy P C, Gregson A K. Temperature dependence of proton spin-lattice relaxation times in some paramagnetic transition metal acetylacetonate complexes. The possible influence of the Jahn-Teller effect on electron spin relaxation. J Am Chem Soc, 1977, 99: 1281–1282
Figgis B N, Reynolds P A, Cable J W. Extreme covalence in the technetium-chlorine bond from polarized neutron diffraction. J Chem Phys, 1993, 98: 7743–7745
Reynolds P A, Figgis B N, Forsyth J B, Tassel F. Covalence and spin polarization in tetraphenylarsonium tetrachloronitridotechnetate(VI) studied by polarized neutron diffraction. J Chem Soc Dalton Trans, 1997, 1447–1453
Best S P, Figgis B N, Forsyth J B, Reynolds P A, Tregenna-Piggot P L W. Spin distribution and bonding in [Mo(OD2)6]3+. Inorg Chem, 1995, 34: 4605–4610
Figgis B N, Reynolds P A, Williams G A. Spin density and bonding in the CoCl 2−4 ion in Cs3CoCl5. Part 2. Valence electron distribution in the CoCl 2−4 ion. J Chem Soc Dalton Trans, 1980, 2339–2347
Guerra C F. Methods and Techniques in Computational Chemistry. Calgliari: STEF. 1995
Baerends E J, Ellis D E, Ros P. Self-consistent molecular Hartreeock-Slater calculations. I. Computational procedure. Chem Phys, 1973, 2: 41–51
Te Velde G, Baerends E J. Numerical integration for polyatomic systems. J Comput Phys, 1992, 99: 84–98
Pontillon Y, Ressouche E, Romero F, Schweizer J, Ziessel R. Spin density in the free radical NitPy(C/C-H). Physica B, 1997, 234–36: 788–789
Brown P J, Capiomont A, Gillon B, Schweizer J. Spin densities in free radicals. J Magn Magn Mater, 1979, 14: 289–294
Kahn O. Molecular Magnetism. New York: VCH Publishers, 1993
Kinoshita M, Turek P, Tamura M, Nozawa K, Shiomi D, Nakazawa Y, Ishikawa M, Takahashi M, Awaga K, Inabe T, Maruyama Y. An organic radical ferromagnet. Chem Lett, 1991, 7: 1225–1228
Ressouche E, Boucherle J X, Gillon B, Rey P, Schweizer J. Spin density maps in nitroxide-copper(II) complexes. A polarized neutron diffraction determination. J Am Chem Soc, 1993, 115: 3610–3617
Author information
Authors and Affiliations
Corresponding author
Additional information
Supported by a JINS (Joint Institute for Neutron Sciences) fellowship and the US National Science Foundation (CHE-0516928).
Rights and permissions
About this article
Cite this article
Dougan, B.A., Xue, Z. Polarized neutron diffraction and its application to spin density studies. Sci. China Ser. B-Chem. 52, 2083–2095 (2009). https://doi.org/10.1007/s11426-009-0199-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11426-009-0199-4