Single‐Crystal‐to‐Single‐Crystal Installation of Ln₄(OH)₄ Cubanes in an Anionic Metallosupramolecular Framework

Abstract

Postsynthetic installation of lanthanide cubanes into a metallosupramolecular framework via a single‐crystal‐to‐single‐crystal (SCSC) transformation is presented. Soaking single crystals of K6[Rh4Zn4O(l‐cys)12] (K6[1]; l‐H2cys=l‐cysteine) in a water/ethanol solution containing Ln(OAc)3 (Ln3+=lanthanide ion) results in the exchange of K+ by Ln3+ with retention of the single crystallinity, producing Ln2[1] (2Ln) and Ln0.33[Ln4(OH)4(OAc)3(H2O)7][1] (3Ln) for early and late lanthanides, respectively. While the Ln3+ ions in 2Ln exist as disordered aqua species, those in 3Ln form ordered hydroxide‐bridged cubane clusters that connect [1]6− anions in a 3D metal‐organic framework through coordination bonds with carboxylate groups. This study shows the utility of an anionic metallosupramolecular framework with carboxylate groups for the creation of a series of metal cubanes that have great potential for various applications, such as magnetic materials and heterogeneous catalysts.

Bond dissociation energies of low-valent lanthanide hydroxides: lower limits from ion–molecule reactions and comparisons with fluorides

“…6 Electropositive lanthanides are particularly prone to solution hydrolysis, [7][8][9] with the resulting hydroxides commonly employed in catalysis, optics and electronics. [10][11][12][13] Understanding hydroxides is often advanced by modeling them as pseudo-halides, particularly as isoelectronic fluorides. [14][15][16][17][18] Similar electronic properties of YbF and YbOH, for example, designate both as prime candidates to evaluate the electric dipole moment of the electron.…”