X-ray powder diffraction characterization of the elusive tetraphosphine Si(CH2PPh2)4 silane Academic Article uri icon

abstract

  • X-ray powder diffraction data for the tetraphosphinic Si (C H2 P Ph2) 4 silane are reported. Its crystal and molecular structures were determined by simulated annealing and full-profile Rietveld refinement methods. Si (C H2 P Ph2) 4 was found to have tetragonal symmetry with P- 421 c space group. The lattice parameters were determined to be a=17.211 (2) Å, c=7.553 (1) Å, V=2237.5 (5) Å3. The crystal structure was found to contain isolated Si (C H2 P Ph2) 4 molecules. In each Si (C H2 P Ph2) 4 molecule, the central Si atom was fixed at the -4 symmetric position bearing four C H2 P Ph2 branches. This environment was confirmed by P31 CP/MAS NMR measurements. Thermo-diffractometric measurements in the 20-120 °C range were also used to estimate the linear and volumetric thermal expansion coefficients ( ln VT=1.8× 10-4 K-1), typical for very "soft" materials. © International Centre for Diffraction Data.

author list (cited authors)

  • Masciocchi, N., Galli, S., Bogza, M., & Blümel, J.

citation count

  • 5

publication date

  • March 2007