Rubidium and caesium aluminyls: synthesis, structures and reactivity in C–H bond activation of benzene

Abstract

Rubidium and caesium aluminyls [M{Al(NONDipp)}]2 have been synthesised but only the caesium compound can oxidatively cleave an aromatic C–H bond of benzene.

Alkali metal influences in aluminyl complexes

“…This is in agreement with the earlier observed Al–N bond contraction with increasing covalency of the Al–M bond. 12,13 This phenomenon was explained by the fact that increasing Al–M bond covalency shifts electron density away from Al to M, consequently strengthening the Al–N bonds.…”

“…11 b ,12 Recently, complex II has been prepared with the full series of alkali metal counter cations Li–Cs. 13 Here we report a further contribution on the effect of the alkali metal cation in aluminyl chemistry. Complex VI has now been structurally characterized with the full series of alkali metal cations Li–Cs.…”

Metallation of sensitive fluoroarenes using a potassium TMP-zincate supported by a silyl(bis)amido ligand

“…This is somewhat surprising since many studies on alkali-metal ates have unearthed a marked alkali-metal effect in the reactivity of such heterobimetallic complexes. 11 Furthermore, mechanistic studies on the ferration of fluoroarenes by sodium trisamidoferrate [NaFe(HMDS) 3 ] (HMDS = N(SiMe 3 ) 2 ) have revealed that initial coordination of the substrate to the alkali-metal via Na⋯F interactions is key for the reaction to take place, which involves a two-step mechanism with initial Na–H exchange followed by fast intramolecular transmetallation to iron. 6 c Interestingly, here, for the zincation of 1,3,5 trifluorobenzene potassium appears to play a secondary role, stabilizing the zincate anion intermediates.…”

Inhibition of Alkali Metal Reduction of 1‐Adamantanol by London Dispersion Effects

“…DOSY NMR spectroscopy confirmed the isolation of 1 and 3 , which have diffusion coefficients of 7.88×10 −10 m 2 s −1 and 8.02×10 −10 m 2 s −1 respectively (Supporting Information). The similar diffusion coefficients of each species suggested that the complexes formed tri‐coordinated structures analogous to that of 2 and have the formula [M(OAd 1 )(HOAd 1 ) 2 ] (M=Li, 1 ; K; 3 ) [26] . This led to the conclusion that there is no change in coordination number with the size of the metal ion.…”

“…The similar diffusion coefficients of each species suggested that the complexes formed tricoordinated structures analogous to that of 2 and have the formula [M(OAd 1 )(HOAd 1 ) 2 ] (M = Li, 1; K; 3). [26] This led to the conclusion that there is no change in coordination number with the size of the metal ion. The lack of other signals in the DOSY spectrum also confirmed that no dissociation of the HOAd 1 molecules occurred in solution at 298 K in C 6 D 6 or THF-D 8 (Supporting Information).…”