Stable Heterometallic Cluster Ions based on Werner's Hexol

Abstract

Large aqueous ions are interesting because they are useful in materials science (for example to generate thin films) but also because they serve as molecular models for the oxide-aqueous mineral interface where spectroscopy is difficult. Here we show that new clusters of the type M[(μ-OH) Co(NH ) ] (NO ) (M=Al, Ga) can be synthesized using Werner's century-old cluster as a substitutable framework. We substituted Group 13 metals into the hexol Co[(μ-OH) Co(NH ) ] ion to make diamagnetic heterometallic ions. The solid-state structure of the hexol-type derivatives were determined by single-crystal XRD and NMR spectroscopy and confirmed that the solid-state structure persists in solution after dissolution into either D O or [D ]DMSO. Other compositions besides these diamagnetic ions can undoubtedly be made using a similar approach, which considerably expands the number of stable aqueous heteronuclear ions.

Stable Heterometallic Cluster Ions based on Werner's Hexol

“…Using am etal nitrate salt to effect the dissociation of the carbonato ligand could also make this approach applicable to the incorporation of other metal ions,given the acidic nature of most metal nitrate salts.A lthough only Group 13 metal ions were tested here,i ti st hought that this approach could apply to any metal acidic enough to affect the dissociation of the carbonato ligand.Thed ata from single-crystal XRD shows that the aluminum analog adopts as imilar structure as the original hexol cluster that contained only cobalt. [17,18] At the center is as ixcoordinate Al 3+ ion, bound with bridging hydroxide ligands that connect it to the outer [Co(NH 3 ) 4 ] 3+ units.T he -NH 3 ligands are split into two chemical environments:either cis to bridging hydroxide ligands or trans to the hydroxide ligands, which can be distinguished in solution (see below). The overall charge on the cluster is balanced with six outer-sphere nitrate ions (Figure 1).One advantage of preparing clusters with diamagnetic Co III and Al III ions is the use of 1 H-NMR and DOSY to understand their solution behavior.T he spectrum obtained for the hexol-type clusters was surprisingly simple,w hich indicated that apure species with high symmetry was present in solution.…”

“…Thed ata from single-crystal XRD shows that the aluminum analog adopts as imilar structure as the original hexol cluster that contained only cobalt. [17,18] At the center is as ixcoordinate Al 3+ ion, bound with bridging hydroxide ligands that connect it to the outer [Co(NH 3 ) 4 ] 3+ units.T he -NH 3 ligands are split into two chemical environments:either cis to bridging hydroxide ligands or trans to the hydroxide ligands, which can be distinguished in solution (see below). The overall charge on the cluster is balanced with six outer-sphere nitrate ions (Figure 1).…”

“…[17,18] At the center is as ixcoordinate Al 3+ ion, bound with bridging hydroxide ligands that connect it to the outer [Co(NH 3 ) 4 ] 3+ units.T he -NH 3 ligands are split into two chemical environments:either cis to bridging hydroxide ligands or trans to the hydroxide ligands, which can be distinguished in solution (see below). [17,18] At the center is as ixcoordinate Al 3+ ion, bound with bridging hydroxide ligands that connect it to the outer [Co(NH 3 ) 4 ] 3+ units.T he -NH 3 ligands are split into two chemical environments:either cis to bridging hydroxide ligands or trans to the hydroxide ligands, which can be distinguished in solution (see below).…”

Stereoisomerism in Tetrametallic Propeller‐Like Complexes: A Solid‐State and Solution NMR Study on a Tetragallium(III) Derivative

“…NMR spectroscopy was extensively used to investigate diamagnetic polynuclear species, among which Werner's hexols [22] and Group 13 complexes. [11,12,14] A freshly prepared solution of 1 4-Py • EtOH in C 6 D 6 affords a very rich and well-resolved 1 H NMR spectrum (Figure 3 and Figures S2-S8).…”

“…Heteronuclear variants were also accessed. [22][23][24] Of special interest are complexes with formula [Fe III 3 M III (L R ) 2 (dpm) 6 ],…”