Utility of Anhydrous Neodymium Nitrate as a Precursor to Extended Organoneodymium Nitrate Networks

Hydrated neodymium nitrates can be readily transformed to anhydrous ether solvates which react with cyclopentadienyl
reagents to make organometallic nitrate complexes with variable degrees of oligomerization. Heating Nd(NO3)3(H2O)6 in tetrahydrofuran at reflux, removal of solvent, drying at 100 °C under high vacuum, and addition of hot
THF generates Nd(NO3)3(THF)3, 1. Using dimethoxyethane, Nd(NO3)3(DME)2, 2, can be obtained similarly. Addition
of NaC5Me5 to 1 generates (C5Me5)Nd(NO3)3(THF)Na(THF)x complexes which crystallize as {[(C5Me5)(NO3)2Nd(THF)(μ-NO3)]2Na(THF)4}[Na(THF)6], 3, or [(C5Me5)Nd(THF)(μ-NO3)3Na(THF)2]n, 4, depending on the conditions.
The trimetallic Nd2Na unit in 3 forms an extended system in 4 via bridging nitrates. Addition of KC5Me5 and 18-crown-6 to 1 generates another extended complex [(C5Me5)Nd(THF)(NO3)(μ-NO3)2K(18-crown-6)]n, 5, in which an
18-crown-6 ligated potassium links neodymium centers via two bridging nitrates and an agostic interaction between
a C5Me5 methyl group and potassium.