Mono‐ and Dinuclear Rare‐Earth Chlorides Ligated by a Mesityl‐Substituted β‐Diketiminate

Abstract

The metathesis reaction of anhydrous LnCl 3 (Ln = Y, Dy, Er, Sm, Yb) with the potassium salt KL [L = 2,4,6-Me 3 C 6 H 2 -NC(Me)CHC(Me)N-2,4,6-Me 3 C 6 H 2 ], a mesityl-substituted -diketiminate, is described. Dinuclear complexes with an unusual triple chlorido bridge in the molecule [LClLn(μ-Cl) 3 LnL(THF)] [Ln = Y (1a) and Dy (1b)] were obtained by recrystallization from a mixture of non-polar solvents (toluene/n-pentane) in low [a] G. A. Razuvaev

Erbium Mixed‐Ligand β‐Diketiminato‐Diamido Complex: Unusual Structure of Diamide Ligand

“…The erbium atom in 1 is above the conjugated N1C2C3C4 N2 fragment in such a way that to some degree it may be regarded as being η 5 ‐bonded to Er1. The deviation of erbium atom from the N1C2C4 N2 plane is much more distinct than in the initial chloride complex [(NacNac)ErCl 2 (THF) 2 ] and amounts 1.388 Å, while the central carbon atom C3 lies 0.169 Å above the same plane. Such a coordination pattern with the appreciable deflection of lanthanide from NacNac backbone is similar to the structure of rare earths complexes with two β‐diketiminato ligands and probably caused by the close location of two bulky ligands.…”

“…In spite of the fact there is an expected delocalization within the π‐system of NacNac. The acute N1‐Er1‐N2 angle of 81.00(8) as well as the slightly asymmetrical Er1‐N1/Er1‐N2 bond lengths with the difference of 0.022 Å are comparable with those found in Ln‐NacNac compounds . The arene rings lie approximately perpendicular to the NCCN plane of β‐diketiminato ligand with the corresponding dihedral angles of 73.2 and 78.6°.…”

“…Only few lanthanide complexes with mesityl‐substituted β‐diketiminates are known . Recently, we have successfully prepared a number of halide complexes supported by mesityl‐substituted β‐diketiminato ligands with the general formulae of [(NacNac)Ln(Cl)(μ‐Cl) 3 Ln(NacNac)(THF)] and [(NacNac)LnCl 2 (THF) 2 ] (NacNac=(MesN−C(Me)CHC(Me) ‐NMes) − ) and thereby extended a range of dimeric triple chloride‐bridged lanthanide complexes and mononuclear lanthanide dichlorides supported by NacNac ligands, respectively.…”

The Exploration and Analysis of the Magnetic Relaxation Behavior in Three Isostructural Cyano-Bridged 3d–4f Linear Heterotrinuclear Compounds

“…Owing to the coordination ability of the sterically hindered ligands and the difficulty of controlling the coordination orientation, the low-coordinate lanthanide compounds with an axial symmetry are more difficult to obtain. Several reported cases include the nearly linear 2-coordinate (D ∞h ) [21], the equatorially coordinated triangle (C 3 ) [22], the trigonal-pyramidal (pseudo-C 3 ) [23], the five-coordinate [24], and the six-coordinate complexes [9,13,20,[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”

“…Relatively lower zero-field energy barriers have been acquired in some six-coordinate Dy-containing examples with a coordination geometry substantially deviated from the ideal octahedron (O h ), such as a trigonal antiprism (U eff = 11 and 14 K) [29], a distorted trigonal prism (U eff = 159 K) [30] and an axially compressed octahedron (for the diluted sample, U eff = 75 K) [31]. Only field-induced energy barriers or even no relaxation parameters could be deduced from the alternating-current (ac) measurements in most of the six-coordinate complexes with more uniform bond lengths [13,[32][33][34][35][36][37][38][39][40][41]. In spite of the above-mentioned six-coordinate dysprosium complexes, as far as we know, an example with a perfect D 4h symmetry has not been found yet [41].…”