Trends in trigonal prismatic Ln-[1]ferrocenophane complexes and discovery of a Ho 3+ single-molecule magnet
Lanthanide metallocenophanes are an intriguing class of organometallic complexes that feature rare six-coordinate trigonal prismatic coordination environments of 4f elements with close intramolecular proximity to transition metal ions. Herein, we present a systematic study of the structural and magnetic properties of the ferrocenophanes, [LnFc 3 (THF) 2 Li 2 ] − , of the late trivalent lanthanide ions (Ln = Gd ( 1 ), Ho ( 2 ), Er ( 3 ), Tm ( 4 ), Yb ( 5 ), Lu ( 6 )). One major structural trend within this class of complexes is the increasing diferrocenyl (Fc 2− ) average twist angle with decreasing ionic radius ( r ion ) of the central Ln ion, resulting in the largest average Fc 2− twist angles for the Lu 3+ compound 6 . Such high sensitivity of the twist angle to changes in r ion is unique to the here presented ferrocenophane complexes and likely due to the large trigonal plane separation enforced by the ligand (>3.2 Å). This geometry also allows the non-Kramers ion Ho 3+ to exhibit slow magnetic relaxation in the absence of applied dc fields, rendering compound 2 a rare example of a Ho-based single-molecule magnet (SMM) more »
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Award ID(s):
Publication Date:
NSF-PAR ID:
10157308
Journal Name:
Chemical Science
Volume:
11
Issue:
15
Page Range or eLocation-ID:
3936 to 3951
ISSN:
2041-6520