Browsing by Author "Craig, DJ"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Central atom size effect on the structure of group 14 tetratolyls
    (Wiley-VCH Verlag Berlin, 2009-07-06) Ng, MCC; Craig, DJ; Harper, JB; van Eijck, L; Stride, JA
    Size matters! The structure and dynamics of the tetratolyl Group 14 elements, which were probed by using high-resolution inelastic neutron scattering spectra, show a remarkable dependence on the size of the central atom. The para-methyl groups at the periphery of the molecules constitute the frontier intermolecular interactions of increasingly larger tetrahedra, which becomes critical at the molecular radius of the Si and Ge analogues. © 2009, Wiley-VCH Verlag Berlin
  • No Thumbnail Available
    Item
    Magneto-structural correlations of a three-dimensional Mn based metal-organic framework
    (Royal Society of Chemistry, 2010-05-14) Nadeem, MA; Craig, DJ; Bircher, R; Stride, JA
    A 3D metal–organic framework, [Na{Mn3(Hbtc)2(btc)}·5H2O]n ( 1) (H3btc = 1,3,5-benzene tricarboxylic acid), was synthesized under hydrothermal conditions. The structure of 1 was established by single crystal X-ray diffraction analysis; 1 crystallizes in the monoclinic space group P2/c, a = 9.753(3) Å, b = 12.751(2) Å, c = 14.174(4) Å, = 109.41(1)°. The complex 1 is isostructural to previously reported MIL-45 and consists of one dimensional wave like chains of carboxylate bridged hexa-coordinated Mn(II) ions. Variable temperature magnetic susceptibility measurements revealed dominant antiferromagnetic exchange interactions and the intra-chain exchange constants J1 = -2.4 cm-1 and J2 = -0.6 cm-1 compare well with literature values for similar materials. Inter-chain interactions are expected to be very small in this compound and there is no indication of magnetic ordering phenomena in the temperature range from 300–2 K. © 2010, Royal Society of Chemistry