Understanding electrostatics and covalency effects in highly anisotropic organometallic sandwich dysprosium complexes [Dy(C_mR_m)₂] (where R = H, SiH₃, CH₃ and m = 4 to 9): a computational perspective

Abstract

In this article, we have thoroughly studied the electronic structure and 4f-ligand covalency of six mononuclear dysprosium organometallic sandwich complexes [Dy(CmRm)2]n+/- (where R = H, SiH3, CH3; m = 4...

Eight-coordinate mono- and dinuclear Dy(iii) complexes containing a rigid equatorial plane and an anisobidentate carboxylate ligand in the axial position: synthesis, structure and magnetism

“…Although OOCR groups are strongly anionic in nature compared to the previously reported complexes with neutral Cy 3 PO/PPh 3 PO ligands, the presence of two –O atoms (η 2 -mode) away from the z -axis (large cone/bite angle) contributes more towards the equatorial ligand field, which is the main factor for the drastically small barrier height in these complexes. 51,52…”

A highly anisotropic family of hexagonal bipyramidal Dy(iii) unsaturated 18-crown-6 complexes exceeding the blockade barrier over 2700 K: a computational exploration

“…7,8 Several strategies have been proposed, including designing two-coordinate linear complexes, shortening the Dy–L axial bonds compared to equatorial bonds, and achieving a higher-order axial symmetry around the Dy( iii ) ion to maximize the barrier height. 5,8–25 Some notable works include the reports of organometallic sandwiched Dy( iii ) complexes with no equatorial ligands showing giant barrier heights between 1500 and 2200 K. 6,24,26–28 In general, these complexes are highly air-sensitive in nature, and a recent theoretical study predicted the maximum barrier height to be 2200 K in the {DyCp 2 } + family, which is a stumbling block for their further application. 27…”

“…7,8 Several strategies have been proposed, including designing two-coordinate linear complexes, shortening the Dy-L axial bonds compared to equatorial bonds, and achieving a higher-order axial symmetry around the Dy(III) ion to maximize the barrier height. 5,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] Some notable works include the reports of organometallic sandwiched Dy(III) complexes with no equatorial ligands showing giant barrier heights between 1500 and 2200 K. 6,24,[26][27][28] In general, these complexes are highly air-sensitive in nature, and a recent theoretical study predicted the maximum barrier height to be 2200 K in the {DyCp 2 } + family, which is a stumbling block for their further application. 27 In general, stabilizing air-stable highly anisotropic Dy(III) complexes requires a large coordination number (CN > 7) and higher-order axial symmetry such as square antiprismatic/ axially compressed octahedral (D 4d /D 4h ), pentagonal bipyramidal (D 5h ) and hexagonal bipyramidal (D 6h ) environments with short Dy-L ax bonds.…”