New polynuclear coordination species containing the ditopic bis(1-imidazolyl)methane (Bim) ligand have been prepared as microcrystalline powders and structurally characterized by ab initio X-ray powder diffraction methods. [Bim(Me2SnCl2)]n (1), [Bim(nBu2SnCl2)]n (3), [Bim(Ph2SnCl2)]n (4), [Bim(MeSnCl3)]n (5), and [Bim(PhSnCl3)]n (6) all contain 1D chains with octahedral tin atoms with trans N−Sn−N linkages (but 4, which displays a cis N−Sn−N linkage). Their thermodiffractometric analysis allowed the estimation of the linear thermal expansion coefficients and strain tensors derived there from. The potential-energy surface of the free Bim ligand (as defined by two torsional degrees of freedom about the two N−CH2 bonds), eventually controlling the length of the repeating unit (polymer elongation), has been estimated using molecular mechanics and correlated with experimental observations.
Structural and Thermodiffractometric Analysis of Coordination Polymers. Part I: Tin Derivatives of the Bim ligand [Bim = Bis(1-imidazolyl)methane])
PETTINARI, Claudio;PETTINARI, Riccardo;DI NICOLA, CORRADO;
2007-01-01
Abstract
New polynuclear coordination species containing the ditopic bis(1-imidazolyl)methane (Bim) ligand have been prepared as microcrystalline powders and structurally characterized by ab initio X-ray powder diffraction methods. [Bim(Me2SnCl2)]n (1), [Bim(nBu2SnCl2)]n (3), [Bim(Ph2SnCl2)]n (4), [Bim(MeSnCl3)]n (5), and [Bim(PhSnCl3)]n (6) all contain 1D chains with octahedral tin atoms with trans N−Sn−N linkages (but 4, which displays a cis N−Sn−N linkage). Their thermodiffractometric analysis allowed the estimation of the linear thermal expansion coefficients and strain tensors derived there from. The potential-energy surface of the free Bim ligand (as defined by two torsional degrees of freedom about the two N−CH2 bonds), eventually controlling the length of the repeating unit (polymer elongation), has been estimated using molecular mechanics and correlated with experimental observations.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.