Yttrium and Lanthanide Diphosphanylamides: Syntheses and Structures of Complexes with one {(Ph₂P)₂N}⁻ ligand in the Coordination Sphere

Abstract

Treatment of the recently reported potassium salt [K(thf)(n)][N(PPh(2))(2)] (n=1.25, 1.5) with anhydrous yttrium or lanthanide trichlorides in THF leads after crystallization from THF/n-pentane (1:2) to the monosubstituted diphosphanylamide complexes [LnCl(2)[(Ph(2)P)(2)N](thf)(3)] (Ln=Y, Sm, Er, Yb). The single-crystal X-ray structures of these complexes show that the metal atoms are surrounded by seven ligands in a distorted pentagonal bipyramidal arrangement, in which the chlorine atoms are located in the apical positions. The diphosphanylamide ligand is always eta(2)-coordinated through the nitrogen atom and one phosphorus atom. Further reaction of [SmCl(2)[(Ph(2)P)(2)N](thf)(3)] with K(2)C(8)H(8) or reaction of [LnI(eta(8)-C(8)H(8))(thf)(3)] with [K(thf)(n)][N(PPh(2))(2)] in THF gives the corresponding cyclooctatetraene complexes [Ln[(Ph(2)P)(2)N](eta(8)-C(8)H(8))(thf)(2)] (Ln=La, Sm). The single crystals of these compounds contain enantiomerically pure complexes. Both compounds adopt a four-legged piano-stool conformation in the solid state. The structures of the A and the C enantiomers were established by single-crystal X-ray diffraction. The more soluble bistrimethylsilyl cyclooctatetraene complex [Y[(Ph(2)P)(2)N](eta(8)-1,4-(Me(3)Si)(2)C(8)H(6))(thf)(2)] was obtained by transmetallation of Li(2)[1,4-(Me(3)Si)(2)C(8)H(6)] with anhydrous yttrium trichloride in THF followed by the addition of one equivalent of [K(thf)(n)][N(PPh(2))(2)]. The (89)Y NMR signal of the complex is split up into a triplet, supporting other observations that the phosphorus atoms are chemically equivalent in solution and, thus, dynamic behavior of the ligand in solution can be anticipated.

Rare‐Earth Metal Bis(dimethylsilyl)amide Complexes Supported by Cyclooctatetraenyl Ligands

“…[50] So far, few COT lanthanum complexes were structurally characterized. The approximate La-Ct distances for (COT)La(η 5 -C 5 Me 4 H)(thf) 2 (2.099 Å), [51] (COT)La(η 5 -C 4 H 7 OCH 2 C 5 H 4 )(thf) (2.067 Å), [52] and O (2.047 Å) [13] appear slightly elongated compared to compound 2 (2.025 Å).…”

“…J. and formation of compound R (Figure 2) was achieved straightforwardly. [13] Figure 2. Structurally characterized COT Ln III complexes with monoanionic N-donor ligands Q, [4] R, [13] S, [32] T, [32] U, [4] V, [12] W, [14,33] X.…”

“…[13] Figure 2. Structurally characterized COT Ln III complexes with monoanionic N-donor ligands Q, [4] R, [13] S, [32] T, [32] U, [4] V, [12] W, [14,33] X. [34] Similarly, heteroleptic COT/N-isopropyl-2-(isopropylamino)troponiminate (V) ( Figure 2: the structurally characterized Y derivative is shown) and COT/bis(phosphinimino)methanide complexes of samarium (W) were obtained from (COT)SmI(thf) 3 (1c) in thf at ambient temperature, W displaying hydroamination/cyclization catalysts.…”

A Phosphine‐Mediated Through‐Space Exchange Coupling Pathway for Unpaired Electrons in a Heterobimetallic Lanthanide–Transition Metal Complex

“…The P(1)···Y(1) distance of 3.2575(6) in 4 is less than 7 % longer than the longest reported YÀP bond length of 3.045(2) , [29] although shorter YÀP bond lengths are more typical. [18,30] In comparison, the P(1)···Gd(1) distance of 3.2440(9) in 5 is actually shorter than the P(1)···Y(1) distance in 4, which can be rationalised by the slightly larger size of the Gd III ion requiring a greater strain in the ancillary ligand fro its accommodation. This assertion is confirmed by the slightly larger sum of C-P-C angles in 5 than in 4, which are 326.70(26) and 324.69(17)8, respectively.…”

New Development in Rare Earth Metal Complexes Containing Anionic Bis(imino)pyrrolyl and Bis(phosphanyl)amide Ligands

“…The single crystal X-ray structure revealed that both complexes 32 and 33 adopt a four-legged piano-stool conformation [46]. [46].…”