Synthesis and Crystal Structures of Monomeric Diamidonickel(II) Complexes

Cobalt(II) amido complexes derived from a monodentate arylamido ligand featuring a highly electron-withdrawing C6F5 substituent

A series of cobalt(ii) complexes of a highly electron-withdrawing amido ligand, [N(C6F5)(C6H3Pr(i)2-2,6)](-) (L), were synthesized and structurally characterized. Mononuclear [CoL(Cl)(TMEDA)] (3) and heterobimetallic [CoL2(μ-Cl)Li(THF)3] (4) were obtained by direct metathetical reactions of anhydrous CoCl2 with one molar equivalent of [LiL(TMEDA)] (1) (TMEDA = Me2NCH2CH2NMe2) and [LiL(THF)3] (2), respectively. Complex 3 underwent facile ligand substitution reactions with LiMe and NaN3, yielding the corresponding mixed-ligand complexes [CoL(X)(TMEDA)] (X = Me 5, N36). Treatment of 3 with NaOMe led to the heterobimetallic complex [CoL2(μ-OMe)Na(TMEDA)] (7). The solid-state structures of complexes 1-7 were established by X-ray diffraction analysis.

Divalent europium and ytterbium complexes supported by a bulky 2-pyridyl amido ligand: synthesis, structure and reactivity studies

Metallation of the N-arylated 2-pyridyl amine [HN(C6H3Pr(i)2-2,6)(2-C5H3N-6-Me)] (1) with potassium hydride in Et2O and THF yielded potassium amides [{KL(OEt2)}2] [L = N(C6H3Pr(i)2-2,6)(2-C5H3N-6-Me)] (2) and KL(THF)2 (3), respectively. Treatment of LnI2(THF)2 (Ln = Eu, Yb) with 2 afforded the corresponding Ln(II) amido complexes [EuL(μ-L)2K(THF)] (4) and [YbL2(THF)2] (5). In contrast, an analogous reaction of SmI2(THF)2 with 2 only led to the isolation of homoleptic Sm(III) triamide [SmL3] (6). The reaction chemistry of divalent complexes 4 and 5 was examined. Oxidation of the Eu(II) amido complex 4 by iodine yielded the trivalent [EuL3] (7), whereas addition of Yb(II) diamide 5 to iodine led to the isolation of the bis(amido) Yb(III) iodide complex [YbL2(I)(THF)] (8). Complex 8 could also be prepared by the reaction of 5 with copper(I) iodide. A subsequent reaction of 8 with KOBut gave, unexpectedly, the Yb(III) triamide [YbL3] (9). Reactions of complex 5 with diphenyl dichalcogenides PhEEPh (E = S, Se, Te) also gave [YbL3] (9) as the only isolable product. The solid-state structures of complexes 2 and 4–9 were elucidated by X-ray diffraction analysis.

Bis(N-triisopropyl-silyl-quinolin-8-aminato)nickel(II)

The reddish-brown title complex, [Ni(C₁₈H₂₇N₂Si)₂], was prepared via the salt-metathesis reaction of N-triisopropyl­silyl-8-amido­quinoline lithium with nickelocene (NiCp₂). The asymmetric unit contains two symmetry-independent mol­ecules with the Ni atoms in distorted tetra­hedral environments.

Synthesis, structure, and reaction chemistry of samarium(II), europium(II), and ytterbium(II) complexes of the unsymmetrical benzamidinate ligand [PhC(NSiMe(3))(NC(6)H(3)Pr(i)(2)-2,6)](-)

Neutral mononuclear lanthanide(II) bis(amidinate) complexes [LnL(2)(THF)(x)] [L = PhC(NSiMe(3))(NC(6)H(3)Pr(i)(2)-2,6)(-); Ln = Sm, x = 2 (3); Ln = Eu, x = 2, (4); Ln = Yb, x = 1 (5)] were synthesized by the reaction of the appropriate LnI(2)(THF)(2) with potassium amidinate [KL](n) (2). The reduction chemistry of 3-5 was also examined. The reaction of the Sm(II) and Eu(II) amidinates 3 and 4 with diphenyl dichalcogenides PhEEPh (E = Se, Te) led to the binuclear lanthanide(III) amidinate-chalcogenolate complexes [LnL(2)(mu-EPh)](2) [Ln = Sm, E = Se (6); Ln = Eu, E = Se (7); Ln = Sm, E = Te (9)], whereas reacting the Yb(II) bis(amidinate) 5 with PhSeSePh yielded the mononuclear [YbL(2)(SePh)(THF)] (8). The reaction of 5 with iodine led to the Yb(III) bis(amidinate) iodide complex [YbL(2)(I)(THF)] (10). Treatment of 3 with N,N'-dicyclohexylcarbodiimide afforded the mixed-ligand Sm(III) tris(amidinate) [SmL(2){CyNC(H)NCy}] (11) (Cy = cyclohexyl). The molecular structures of complexes 2-5 and 7-11 were elucidated by X-ray diffraction analyses.