Stoichiometric control: 8- and 10-coordinate Ln(hfac)3(bpy) and Ln(hfac)3(bpy)2 complexes of the early lanthanides La-SmElectronic supplementary information (ESI) available: Crystallographic details and CIF files for Ln(hfac)3(bpy) (Ln = La, Ce, Pr, Nd, Sm and Ln(hfac)3(bpy)2 (Ln = Ce, Pr, Nd, Sm); IR, DSC and PXRD characterization of mechanochemical reactions. CCDC 1856921 (Labpy), 1856922 (Cebpy), 1856925 (Prbpy), 1856926 (Ndbpy), 1856928 (Smbpy), 1856929 (Cebpy2), 1858639 (Prbpy2), 1856933 (N

• Main Authors: Fatila, Elisabeth M, Maahs, Adam C, Hetherington, Erin E, Cooper, Brandon J, Cooper, Riley E, Daanen, Nick N, Jennings, Michael, Skrabalak, Sara E, Preuss, Kathryn E
• Format: Article
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c8dt03286f

The coordination sphere of early lanthanide( iii ) ions is highly versatile, exhibiting the ability to form 8-, 9-, and 10-coordinate complexes with the same ligand set. The ability to isolate 10-coordinate complexes decreases across the period, and the late lanthanides typically cannot support a coordination number higher than eight. Using two common, commercially available ligands, hfac (1,1,1,5,5,5-hexafluoroacetylacetonato-) and bpy (2,2′-bipyridine), the 8- and 10-coordinate series Ln(hfac) 3 (bpy) and Ln(hfac) 3 (bpy) 2 (Ln = La-Sm) are compiled in a single investigation, demonstrating that the desired coordination number can be targeted through stoichiometry. Solvent-free syntheses of Ln(hfac) 3 (bpy) and Ln(hfac) 3 (bpy) 2 complexes from Ln(hfac) 3 (H 2 O) 3 precursors are investigated using a mechanochemical approach. Structural and spectroscopic properties as well as melting point trends are reported for the series. Solution and mechanochemistry are used to obtain 8- and 10-coordinate complexes of the lanthanides La-Sm Ln(hfac) 3 (bpy) X ( X = 1, 2).