Abstract
The hydrous lanthanide oxides and hydroxides comprise a complex series of both amorphous and crystalline compounds. One important member of this system is the hexagonal form of M(OH) 3 where M studied here are La, Nd, Sm, Gd, Tb, Dy, Ho, Y and Er. The lattice constants and structure for these nine isotypic compounds has been determined by three-dimensional X-ray diffraction. The space group is P6 3/ m or P6 3 with two formula units per cell. The metal is 9-coordinate (tri-capped trigonal prism) with two independent metal-oxygen bond distances and three independent oxygenz.sbnd;oxygen bond distances. The metaloxygenoxygen bond distances both exhibit monotonic decreases proceeding from La to Er. The metal to oxygen distances range from 2.588(3) Å to 2.403(3) Å for MO 2 and from 2.551(3) Å to 2.439(3) Å for MO 1. At the low atomic number end of the series the MO 1, bond distance is shorter than the MO 2 bond distance. The two bond distances become the same at the spherically symmetric gadolinium and switch in relative magnitude as you proceed to erbium. The oxygenoxygen bond distances range from 3.033(5) Å to 2.856(5) Å for O 1O 2, 2.992(6) Å to 2.826(7) Å for O 2O 2 and 2.900(6) Å to 2.710(6) Å for the second O 1O 2 bond distance. Approximate positions for the hydrogen atoms have been found for the M(OH) 3 compounds Gd, Dy, Ho, Y and Er. A set of crystal radii for the lanthanides La, Nd, Sm, Gd, Tb, Dy, Ho and Er has been derived.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.