Synthesis of Unsupported Ln–Ga Bonds by Salt Metathesis and Ga–Ga Bond Reduction

Abstract

Three gallyl lanthanide complexes [{(dipp-Bian)Ga} 2 Ln(thf) 4 ] (Ln = Sm, Eu, Yb; dipp-Bian = 1,2-bis[(2,6diisopropylphenyl)imino]acenaphthene), in which the lanthanide atoms are coordinated by only two {(dipp-Bian)Ga} − ligands and THF, are reported. Two unsupported Ln−Ga bonds are found in each compound. The gallyl lanthanide complexes have been obtained by two synthetic pathways: (1) reductive insertion of the lanthanide metals into the Ga−Ga bond of [{(dipp-Bian)Ga}] 2 and (2) salt metathesis of [(dipp-Bian)GaK(thf) 5 ] with LnI 2 . Moreover, the samarium compound [{(dipp-Bian)Ga} 2 Sm(thf) 4 ] was additionally obtained in a reductive pathway from SmI 3 and [(dipp-Bian)GaK(thf) 5 ]. The length of the Ln−Ga bond strongly depends on packing effects. The reaction of TmI 2 (thf) 5 and [(dipp-Bian)GaK(thf) 5 ] gave the Tm(III) complex [{(dipp-Bian)Ga−Ga(dipp-Bian)}(C 4 H 8 O)TmI(thf) 5 ], in which one THF ring was opened and reduced twice, forming the formal double negative charged anion (O-CH 2 -CH 2 -CH 2 -CH 2 ) 2− . This thulium compound and its dysprosium analogue [{(dipp-Bian)Ga−Ga(dipp-Bian)}(C 4 H 8 O)DyI(thf) 5 ] were also obtained in an alternative approach by reacting LnI 2 (thf) x (Ln = Tm, Dy) with [(dipp-Bian)Ga] 2 in THF. All new compounds were structurally characterized by single-crystal X-ray diffraction. The ytterbium complex shows the shortest Yb(II)−Ga bond distances reported so far.

Different Reductive Reactivities of SmCpx2(THF)n (Cpx = C5Me5 and C5H3tBu2) Samarocenes toward P2Ph4: THF Ring-Opening and Ligand-Exchange Pathways

“…Complex [(AlCH 2 SiMe 3 ) 2 {μ-O­(CH 2 ) 4 PPh 2 Cr­(CO) 5 } 2 ] 2 is also worth mentioning as it represents the μ 3 :κ 2 O ,κ P - fashion of coordination, where the O atom bridges two hard ions Al 3+ and the soft PPh 2 terminus is coordinated to the soft Cr 0 center . Besides the phosphido complexes, THF ring-opening in the coordination sphere of lanthanide complexes was described for several cases initiated by other nucleophilic ligands, such as H – , Cp* – , and cyclopentaphosphido ligand entering the Ln coordination sphere …”

f‐Element–Metal Bonding and the Use of the Bond Polarity To Build Molecular Intermetalloids

“…in 2011, reveals some common features with C11 to C16 in that both gallium‐containing fragments rely on closely related, redox‐active ligands (DAD and BIAN, respectively). The compounds were obtained by salt metathesis and the less symmetrically substituted derivative C20 could be characterized by X‐ray diffraction, showing a tetrahedral lanthanum coordination sphere with a La–Ga bond length of 301.34(8) pm 66…”

Activation of Nitrogen-Rich Substrates by Low-Valent, Redox-Active Aluminum Species

“…Our research interest is focused on study of the reactivity of low-valent group 13 metal derivatives, [LM–ML] (L a = dpp-dad; L b = dpp-Bian; M = Ga and Al), containing a metal–metal bond. − These compounds are able to undergo a rich variety of reactions, such as reduction by alkali , and alkaline earth metals; lanthanides; oxidative addition processes; solvate-induced intramolecular electron transfer; and cycloaddition of alkynes. − They are also catalysts for polymerization of cyclic esters. , One of the promising findings for these compounds is their ability to activate cumulated unsaturated (C–C and C–E) bonds, leading to diverse reaction pathways. − Given the excellent reactivity of these dialumanes and digallanes, and a paucity of their use in generating imido derivatives, herein we report on the reactions of dialumanes [L 2– Al–AlL 2– ] (L a , 1a , and L b , 1b ) with nitrogen-rich compounds (azides, azo, diazo-compounds), which lead to a series of imido, diazoimide, and diazo-bridged dinulcear Al III complexes.…”