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Dr Stuart Batten

Stuart Batten Senior Lecturer
BSc(Hons), PhD, MRACI, C.Chem, GCHE
Address: School of Chemistry, Monash University 3800, Australia.
Telephone: (03) 9905 4606
Fax: (03) 9905 4597
Email: stuart.batten@sci.monash.edu.au
Web: http://www.chem.monash.edu.au/staff/sbatten/index.html
   
 

Chemistry of Pseudohalide Anions

In conjunction with Prof. Keith Murray, we have been studying the structures and magnetism of the coordination polymers of the less-common pseudohalide ligands, such as dicyanamide (dca, N(CN)2-) and tricyanomethanide (tcm, C(CN)3-). We have discovered a new class of magnetically ordering compounds that has sparked a surge in interest in dca coordination polymers. The α-[M(dca)2] compounds all have rutile-like structures in which octahedral metal centres are bridged by three-connecting dca ligands (which coordinate through all three nitrogen atoms). Despite their isomorphous structures, the magnetic properties vary widely: Cr, Mn and Fe are spin-canted antiferromagnets (TN = 47, 16, 19 K), Co, Ni and Cu are ferromagnets (Tc = 9, 21, 1.7 K). The ß-[M(dca)2] phase is formed by tetrahedral metals, and is composed of (4,4) 2D sheets of metals bridged by μ2 ligands (the amide nitrogen does not coordinate). The effect of structure on magnetic properties is illustrated by the fact that both phases can be isolated for M = Co, however while the α phase is a ferromagnet, the ß phase is a spin-canted antiferromagnet (TN = 9 K). The dimensionality of the dicyanamide coordination polymers can also be reduced by the introduction of terminal solvent ligands such as H2O, MeOH, EtOH, DMF and pyridine. An unusual tube-like 1D polymer is formed when 2-aminopyridine is added to the reaction mixture; the topology of the tube is identical to the square channels in the α-[M(dca)2] rutile-like networks.

Polymorphism and pseudo-polymorphism is common in dca coordination polymers. In addition to the α and ß forms of [M(dca)2], α-[Cu(dca)2(pyz)] contains two interpenetrating α-Po-like 3D networks, while the ß form contains 2D (4,4) sheets. Two compounds are isolated from a reaction mixture containing Cu(I), dca and 4,4'-bipyridine whose formulae differ only by the number of solvent molecules in the structure; one contains 1D ladder-like polymers while the other has a thick 2D layer structure. This latter compound displays 2D parallel interpenetration, with each layer interlocked with four others. The mean planes of the layers, however, are parallel but not coincident, and thus the interlocking generates an overall 3D structure rather than the usual formation of 2D layers. Cu(dca)(bpe), bpe = 1,2-bis(4-pyridyl)ethene also has an α phase (twofold parallel interpenetration of (4,4) 2D sheets) and a ß phase (five interpenetrating diamond like nets in which the topology of interpenetration is unprecedented).

We have also studied extensively, in collaboration with Prof. Glen Deacon, the coordination polymers and complexes formed between these pseudohalide ligands and lanthanoid metal ions. As well as dca and tcm, we have also combined other closely related ligands with lanthanoid and transition metals to generate fascinating new molecular, multinuclear and polymeric species.

In collaboration with Prof. Doug MacFarlane, we have been investigating the formation and properties of ionic liquids containing pseudohalide anions.

Selected References

  • "Structure and Magnetism of Coordination Polymers Containing Dicyanamide and Tricyanomethanide", Stuart R. Batten and Keith S. Murray, Coord. Chem. Rev., 2003, 246, 103-130.
  • "Ionic Liquids Based on Imidazolium and Pyrrolidinium Salts of the Tricyanomethanide Anion", Stewart A. Forsyth, Stuart R. Batten, Qing Dai and Douglas R. MacFarlane, Aust. J. Chem., 2004, 57, 121-124.
  • "Structure and magnetism of trinuclear and tetranuclear mixed valent manganese clusters from dicyanonitrosomethanide derived ligands", David J. Price, Stuart R. Batten, Kevin J. Berry, Boujemaa Moubaraki and Keith S. Murray, Polyhedron, 2003, 22,165-176.
  • "Syntheses, crystal structures, and magnetic properties of first row transition metal coordination polymers containing dicyanamide and 4,4'-bipyridine", Paul Jensen, Stuart R. Batten, Boujemaa Moubaraki and Keith S. Murray, J. Chem. Soc., Dalton Trans., 2002, 3712-3722.
  • "New 2D coordination polymers containing both bidentate and tridentate dicyanamide bridges and intercalated phenazine", Anna M. Kutasi, Stuart R. Batten, Boujemaa Moubaraki and Keith S. Murray, J. Chem. Soc., Dalton Trans., 2002, 819-821.
  • "Cation Templation of Anionic Metal Dicyanamide Networks", Patricia M. van der Werff, Stuart R. Batten, Paul Jensen, Boujemaa Moubaraki and Keith S. Murray, Chem. Commun., 2000, 2331-2332.
  • "Anionic metal dicyanamide networks with paramagnetic counter-cations", Stuart R. Batten, Paul Jensen, Boujemaa Moubaraki and Keith S. Murray, Chem. Commun., 2000, 2331-2331.
  • "Infinite molecular tubes: structure and magnetism of M(dca)2(apym), M = Co, Ni, apym = 2-aminopyrimidine, dca = dicyanamide, N(CN)2-", Paul Jensen, Stuart R. Batten, Boujemaa Moubaraki and Keith S. Murray, Inorg. Chem., 2001, 40 1718-1722.
  • "Self-Penetration - a Structural Compromise between Single Networks and Interpenetration: Magnetic Properties and Crystal Structures of [Mn(dca)2(H2O)] and [M(dca)(tcm)], M = Co, Ni, Cu, dca = Dicyanamide, N(CN)2-, tcm = Tricyanomethanide, C(CN)3-", Paul Jensen, David J. Price, Stuart R. Batten, Boujemaa Moubaraki and Keith S. Murray, Chem. Eur. J., 2000, 6, 3186-3195.
  • "Crystal structures and magnetic properties of the interpenetrating rutile-related compounds M(tcm)2 [M = octahedral, divalent metal; tcm- = tricyanomethanide, C(CN)3-] and the sheet structures of [M(tcm)2(EtOH)2] (M = Co or Ni)", Stuart R. Batten, Bernard F. Hoskins, Boujemaa Moubaraki, Keith S. Murray and Richard Robson, J. Chem. Soc., Dalton Trans., 1999, 2977-2986.
  • "Syntheses, Structures and Magnetism of α-Mn(dca)2, Mn(dca)2(H2O)2.H2O, Mn(dca)2(C2H5OH)2.(CH3)2CO, Fe(dca)2(CH3OH)2 and Mn(dca)2(L)2, where L = pyridine, CH3OH, DMF and dca-= Dicyanamide, N(CN)2-, Stuart R. Batten, Paul Jensen, Cameron J. Kepert, Mohamedally Kurmoo, Boujemaa Moubaraki, Keith S. Murray and David J. Price, J. Chem. Soc., Dalton Trans., 1999, 2987-2997.
  • "Structural isomers of M(dca)2 molecule-based magnets. Crystal structure of tetrahedrally coordinated sheet-like ß-Zn(dca)2 and ß-Co/Zn(dca)2, and the octahedrally coordinated rutile-like α-Co(dca)2, where dca-= dicyanamide, N(CN)2,-, and magnetism of ß-Co(dca)2", Paul Jensen, Stuart R. Batten, Gary D. Fallon, Boujemaa Moubaraki, Keith S. Murray and David J. Price, Chem. Commun., 1999, 177-178.
  • "Structure and Molecular Magnetism of the Rutile-Related Compounds M(dca)2, M = CoII, NiII, CuII, dca = dicyanamide, N(CN)2-", Stuart R. Batten, Paul Jensen, Boujemaa Moubaraki, Keith S. Murray and Richard Robson, Chem. Commun., 1998, 439-440.