Mono-, Di-, and Trianionic β-Diketiminato Ligands:  A Computational Study and the Synthesis and Structure of [(YbL)₃(THF)], L = [{N(SiMe₃)C(Ph)}₂CH]

Abstract

A trinuclear Yb beta-diketiminato cluster [(YbL)3(THF)] (1) (L = {N(SiMe3)C(Ph)}2CH), containing L-1 and L-3 as well as Yb(II) and Yb(III) centers, was obtained by treatment of [YbL2] with Yb-naphthalene and was characterized by X-ray crystallography. The electron distribution in 1 and the Yb(II)/L-2 complex [Yb{(mu-L)Li(THF)}2] (2) was analyzed by DFT and ONIOM (QM/MM) calculations.

Metal β-diketiminates revisited: ansa-CH2-bridged bis(β-diketiminate)s of lithium and aluminium having diverse structures

“…In N and O the ligand [{N(R)C(Ph)} 2 CH] (" L Ph,Ph ) was regarded as dianionic. In P two of the ligands were assigned as trianionic, one bound to Yb(II) and the other to Yb(III), while the third b-diketiminate was attached to Yb(II); these features are indicated schematically in P. The X-ray data on the crystalline complexes N-P were consistent with the ligand charge distribution shown in valence bond terms in Scheme 1 [12,13]; particularly sensitive probes are the values of the C-N and C-C bond lengths. Structures N-P also illustrate thus far unique bonding modes: both N, N 0 -bridging and chelating in N and O, and multicentred chelating and bridging for the trianionic ligands in P.…”

“…3) may be compared with those for Al(Me) 2 [14]. The 1 H, 13 C, 27 Al, and 29 Si NMR spectra of 7 in C 6 D 6 at 333 K were fully consistent with the structure of the crystalline molecule. The bridging CH 2 group 1 H NMR spectral chemical shift was unexceptional at d 2.83, in contrast to the higher frequency shifts recorded for 5 and 6.…”

“…Rarer are the monodentate N-(as in K [9] C N C Of the more than 500 known b-diketiminatometal complexes, in every case but three the ligand has been monoanionic. The exceptions were the ytterbium complexes N [12], O [12] and P [13]. In N and O the ligand [{N(R)C(Ph)} 2 CH] (" L Ph,Ph ) was regarded as dianionic.…”

On the non-innocence of “Nacnacs”: ligand-based reactivity in β-diketiminate supported coordination compounds

“…49 In the case of Sm(II), which is more reducing than Yb(II), a metal-to-ligand electron transfer occurs: the reaction of KBDI TMS,Ph with SmI 2 yields the Sm(III) complex [KSm(BDI TMS,Ph ) 2 ] 2 . 49,51,52 The scope of this ligand set was expanded to aluminium: reduction of Al(BDI TMS,Ph )Me 2 with excess potassium yields highly air-sensitive dark-violet crystals of [K(OEt)] 2 [Al(BDI TMS,Ph )Me 2 ] whose structure is consistent with the BDI ligands being doubly reduced (Scheme 6). Note that various Yb and Sm related derivatives are obtained under different sets of conditions.…”

Effect of the f-Orbital Delocalization on the Ligand-Field Splitting Energies in Lanthanide-Containing Elpasolites

“…64 Solid and dotted lines are used to indicate (a) ∆ 1 and (b) ∆ 2 parameters, respectively. Squares, circles, diamonds, and stars are used to guide the eye for calculated values corresponding to LnF 6 3-, LnCl 6 3-, LnBr 6 3-, and LnI 6 3-, respectively.…”