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[{SiNDipp}BeClM]2 ({SiNDipp} = {CH2SiMe2N(Dipp)}2; M = Li, Na, K, Rb) are converted to ionic species by treatment with a crown ether. Whereas the lithium derivative reacts with Na or K to provide [{SiNDipp}BeCl]−[M(12-cr-4)2]+ (M = Na, K), the resultant sodium species is resistant to reduction by potassium. These observations are rationalised by a hybrid experimental/theoretical analysis. [ABSTRACT FROM AUTHOR]

The dimeric β-diketiminato calcium hydride, [(BDI)CaH]2 (BDI = HC{(Me)CN-2,6-iPr2C6H3}2), reacts with ZnMe2 to afford the bimetallic calcium zincate complex, [(BDI)Ca(μ-CH3)2Zn(μ-H)]2, which subsequently undergoes an intramolecular reaction to effect the formation of [(BDI)CaMe]2, a notable omission from the homologous series of β-diketiminato alkylcalcium derivatives. [ABSTRACT FROM AUTHOR]

Reduction of [Mg(NON)]2 ([NON]2− = [O(SiMe2NDipp)2]2−, Dipp = 2,6-iPr2C6H3) affords Mg(I) species containing NON- and NNO-ligands ([NNO]2− = [N(Dipp)SiMe2N(Dipp)SiMe2O]2−). The products of reactions with iPrN＝C＝NiPr and CO are consistent with the presence of reducing Mg(I) centres. Extraction with THF affords [K(THF)2]2[(NNO)Mg–Mg(NNO)] with a structurally characterised Mg–Mg bond that was examined using density functional theory. [ABSTRACT FROM AUTHOR]

The hypercoordinate [SiH6]2− anion is not stable in solution. Here, we report the room temperature, solution stable molecular [SiH6]2− complex, [{KCa(NON)(OEt2)}2][SiH6] (NON=4,5‐bis(2,6‐diisopropylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethyl‐xanthene)), where the [SiH6]2− anion is stabilised within a supramolecular assembly that mimics the solid‐state environment of the anion in the lattice of K2SiH6. Solution‐state reactivity of the complex towards carbon monoxide, benzaldehyde, azobenzene and acetonitrile is reported, yielding a range of reduction and C−C coupled products. [ABSTRACT FROM AUTHOR]

The application of Mg[Ph4Pn] and Li·K[Ph4Pn] in transmetalation reactions to a range of Rh(I) precursors led to the formation of "half-baguette" anti-[Rh I(L) n ]2[μ:η5:η5Ph4Pn] (L = 1,5-cyclooctadiene, norbornadiene, ethylene; n = 1, 2) and syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] complexes as well as the related iridium complex anti-[Ir I(COD)]2[μ:η5:η5Ph4Pn]. With CO exclusive syn metalation was obtained even when using mono-nuclear Rh(I) precursors, indicating an electronic preference for syn metalation. DFT analysis showed this to be the result of π overlap between the adjacent M(CO)2 units which overcompensates for dz2 repulsion of the metals, an effect which can be overridden by steric clash of the auxiliary ligands to yield anti-configuration as seen in the larger olefin complexes. syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] is a rare example of a twinned organometallic where the two metals are held flexibly in close proximity, but the two d8 Rh(I) centres did not show signs of M–M bonding interactions or exhibit Lewis basic behaviour as in some related mono-nuclear Cp complexes due to the acceptor properties of the ligands. The ligand substitution chemistry of syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] was investigated with a series of electronically and sterically diverse donor ligands (P(OPh)3, P(OMe)3, PPh3, PMe3, dppe) yielding new mono- and bis-substituted complexes, with E-syn-[Rh I(CO)(P{OR})3]2[μ:η5:η5Ph4Pn] (R = Me, Ph) characterised by XRD. [ABSTRACT FROM AUTHOR]

The aluminacyclopropane K[Al(NON)(η-C2H4)] ([NON]2− = [O(SiMe2NDipp)2]2−, Dipp = 2,6-iPr2C6H3) reacts with CO2 and iPrN＝C＝NiPr to afford ring-expanded products of C–C bond formation. The latter system undergoes a 1,3-silyl retro-Brook rearrangement of the NON-group, to afford the [NNO]2− ligand ([NNO]2− = [N(Dipp)SiMe2N(Dipp)SiMe2O]2−). The mechanism of transformation was examined by density functional theory (DFT). [ABSTRACT FROM AUTHOR]

The breaking of the asymmetric B−B bond within a MgII diboranate complex, [Mg](pinBB(nBu)pin) when [(MeBDIDipp)Mg]≡[Mg], in the presence of DMAP (4‐dimethylaminopyridine), is analyzed with DFT (Density Functional Theory) and NBO (Natural Bond Orbital) methods. The formation of a magnesium‐boryl species, [Mg](Bpin)(DMAP)], which exhibits boron "umpolung" nucleophilic behaviour, is explored through "inner" and "outer" sphere mechanisms, alongside a spontaneous base capture pathway. Charges, bond occupancies, Frontier Orbitals and a steric parameter are used to rationalise the mechanistic features of the system, as well as various reactivity observations. Functional testing results and attempts to model unusual 11B NMR data are also reported. [ABSTRACT FROM AUTHOR]

A simple sequential addition protocol for the reductive coupling of ketones and aldehydes by a potassium aluminyl grants access to unsymmetrical pinacolate derivatives. Isolation of an aluminium ketyl complex presents evidence for the accessibility of radical species. Product release from the aluminium centre was achieved using an iodosilane, forming the disilylated 1,2‐diol and a neutral aluminium iodide, thereby demonstrating the steps required to generate a closed synthetic cycle for pinacol (cross) coupling at an aluminyl anion. [ABSTRACT FROM AUTHOR]

[{SiNDipp}MgNa]2 ({SiNDipp} = {CH2SiMe2N(Dipp)}2; Dipp = 2,6-i-Pr2C6H3) reacts directly with H2 to provide a heterobimetallic hydride. Although the transformation is complicated by the simultaneous disproportionation of magnesium, computational density functional theory (DFT) studies suggest that this reactivity is initiated by orbitally-constrained and interactions between the frontier MOs of both H2 and the tetrametallic core of [{SiNDipp}MgNa]2. [ABSTRACT FROM AUTHOR]

Ionic compounds containing sodium cations are notable for their stability and resistance to redox reactivity unless highly reducing electrical potentials are applied. Here we report that treatment of a low oxidation state {Mg2Na2} species with non‐reducible organic bases induces the spontaneous and completely selective extrusion of sodium metal and oxidation of the MgI centers to the more conventional MgII state. Although these processes are also characterized by a structural reorganisation of the initially chelated diamide spectator ligand, computational quantum chemical studies indicate that intramolecular electron transfer is abetted by the frontier molecular orbitals (HOMO/LUMO) of the {Mg2Na2} ensemble, which arise exclusively from the 3s valence atomic orbitals of the constituent sodium and magnesium atoms. [ABSTRACT FROM AUTHOR]