1. Write the Bragg equation and identify each symbol. X-ray from a palladium source ( λ = 0.576 Å) were reflected by a sample of copper at an angle 9.40°. This reflection corresponds to the unit cell length (d = a) with n = 2 in the Bragg equation. Calculate the length of the copper in cell.
2.Determine all the symmetry operations and elements (Cn, Sn, σ, E, i) for the following compounds:
i) PCl3Br2 molecule – trigonal bipyramid
ii) [PtClF2Br]2- molecule
iii) [RuBr2Cl2H2]2+ an octahedral complex
iv) Benzene derivative
v) [Co(NH3)4Cl2]+ molecule
3.b) Determine the point group of the following:
i) Test tube
. ii) C5H2CI3 molecule (planar)
iii) 5-Chloro-1,3-cyclopentadiene (planar)
iv) Mineral cube complex below
v) A dx2-y2 orbital
1.) Bragg's law provides the condition for a plane wave to be diffracted by a family of lattice planes: 2dsinθ=nλ. where d is the lattice spacing, θ the angle between the wavevector of the incident plane wave, ko, and the lattice planes, λ its wave length and n is an integer, the order of the reflection.
2.) PCl3Br2 molecule – trigonal bipyramid
[RuBr2Cl2H2]2+ an octahedral complex
3.) Determine if the molecule is of high or low symmetry. If not, find the highest order rotation axis, Cn. Determine if the molecule has any C2 axes perpendicular to the principal Cn axis. If so, then there are n such C2 axes, and the molecule is in the D set of point groups.