Molecular structure of erbium trichloride monomer and dimer by electron diffraction and mass spectrometric data

A simultaneous electron diffraction and mass spectrometric experiment was performed to investigate erbium trichloride vapor at 1134(20) K. The vapor contains 97(2) mol.% monomer and 3(2) mol.% dimer. For the ErCl3 molecule, the following parameters were found: rg(Er-Cl) 2.430(5) å, rg(Cl-Cl) 4.036(19) å, effective angle CIErCl 112.3(1.2)‡; with vibrational corrections included, these values correspond to the pyramidal equilibrium configuration of the molecule. For the dimer, a stmcture of D2h, symmetry with four bridging bonds was adopted and the following parameters were found: rg(Er-Cl1) 2.444(5) å, rg(Er-Clh) 2.65(4) å, ∠Cl1-Er-Cl1 117(5)°, ∠Clb-Er-Clb 84(10)°.