TY - JOUR
T1 - A Trinuclear Gadolinium Cluster with a Three-Center One-Electron Bond and an S = 11 Ground State
AU - McClain, K. Randall
AU - Kwon, Hyunchul
AU - Chakarawet, Khetpakorn
AU - Nabi, Rizwan
AU - Kragskow, Jon G. C.
AU - Chilton, Nicholas F.
AU - Britt, R. David
AU - Long, Jeffrey R.
AU - Harvey, Benjamin G.
N1 - Publisher: American Chemical Society
PY - 2023/4/17
Y1 - 2023/4/17
N2 - The recent discovery of metal–metal bonding and valence delocalization in the dilanthanide complexes (CpiPr5)2Ln2I3 (CpiPr5 = pentaisopropylcyclopentadienyl; Ln = Y, Gd, Tb, Dy) opened up the prospect of harnessing the 4fn5dz21 electron configurations of non-traditional divalent lanthanide ions to access molecules with novel bonding motifs and magnetism. Here, we report the trinuclear mixed-valence clusters (CpiPr5)3Ln3H3I2 (1-Ln, Ln = Y, Gd), which were synthesized via potassium graphite reduction of the trivalent clusters (CpiPr5)3Ln3H3I3. Structural, computational, and spectroscopic analyses support valence delocalization in 1-Ln resulting from a three-center, one-electron σ bond formed from the 4dz2 and 5dz2 orbitals on Y and Gd, respectively. Dc magnetic susceptibility data obtained for 1-Gd reveal that valence delocalization engenders strong parallel alignment of the σ-bonding electron and the 4f electrons of each gadolinium center to afford a high-spin ground state of S = 11. Notably, this represents the first clear instance of metal–metal bonding in a molecular trilanthanide complex, and the large spin–spin exchange constant of J = 168(1) cm–1 determined for 1-Gd is only the second largest coupling constant characterized to date for a molecular lanthanide compound.
AB - The recent discovery of metal–metal bonding and valence delocalization in the dilanthanide complexes (CpiPr5)2Ln2I3 (CpiPr5 = pentaisopropylcyclopentadienyl; Ln = Y, Gd, Tb, Dy) opened up the prospect of harnessing the 4fn5dz21 electron configurations of non-traditional divalent lanthanide ions to access molecules with novel bonding motifs and magnetism. Here, we report the trinuclear mixed-valence clusters (CpiPr5)3Ln3H3I2 (1-Ln, Ln = Y, Gd), which were synthesized via potassium graphite reduction of the trivalent clusters (CpiPr5)3Ln3H3I3. Structural, computational, and spectroscopic analyses support valence delocalization in 1-Ln resulting from a three-center, one-electron σ bond formed from the 4dz2 and 5dz2 orbitals on Y and Gd, respectively. Dc magnetic susceptibility data obtained for 1-Gd reveal that valence delocalization engenders strong parallel alignment of the σ-bonding electron and the 4f electrons of each gadolinium center to afford a high-spin ground state of S = 11. Notably, this represents the first clear instance of metal–metal bonding in a molecular trilanthanide complex, and the large spin–spin exchange constant of J = 168(1) cm–1 determined for 1-Gd is only the second largest coupling constant characterized to date for a molecular lanthanide compound.
U2 - 10.1021/jacs.3c00182
DO - 10.1021/jacs.3c00182
M3 - Article
SN - 0002-7863
VL - 145
SP - 8996
EP - 9002
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 16
ER -