Synthesis and structural analysis of lanthanide perfluoropinacolates

Abstract

Three new lanthanide perfluoropinacolate complexes ([K(THF)2][Ln(pinF)2(THF)x] (x = 3, Ln = Pr; x = 2, Ln = Tb, Ho)) have been synthesized and their solid-state structures were collected via single crystal X-ray diffractometry. Due to the fluorination of the pinacolate ligands, these complexes could display interesting electrochemical and luminescent properties. The bond angles and lengths of all three complexes were analyzed and it was found that the bond lengths in [K(THF)2][Tb(pinF)2(THF)2] and [K(THF)2][Ho(pinF)2(THF)2] were shorter than in [K(THF)2][Pr(pinF)2(THF)3]. As a result of these shorter bond lengths the bond angles in [K(THF)2][Tb(pinF)2(THF)2] and [K(THF)2][Ho(pinF)2(THF)2] were larger than in the [K(THF)2][Pr(pinF)2(THF)3] complex. This is due to a reduction in the radii of the lanthanide metal center, with praseodymium (Pr) being the largest of the three, terbium (Tb) the second, and holmium (Ho) the smallest, having ionic radii of 99.0 pm, 92.3 pm, and 90.1 pm, respectively.