Bimetallic complexes containing direct metal-metal bonds occupy an important position in many aspects of coordination chemistry and catalysis. The reactivity of these compounds often differs from that shown by their monometallic analogues as the two metal centres complement each other in a synergistic manner. Aluminium is a p-block metal whose compounds can exhibit Lewis amphoteric properties based largely on its oxidation state, where Al(III) is considered as a Lewis acid and Al(I) can behave as a Lewis base. As such, bimetallic compounds containing Al-M bonds offer a wealth of opportunity for the development of new chemistry and reactivity. The recent development of aluminyl anions as a class of compound in which the Al(I) centre displays nucleophilic properties has facilitated access to a range of bimetallic Al-M species. These compounds complement an existing family of Al-M complexes derived from neutral Al(I) sources and the chemistry of these compounds is undergoing a resurgence of interest. This review brings together recent developments in the field of bimetallic Al-M compounds, where M = s-/p-block metal. It focusses on compounds derived from low-valent Al(I) sources and describes the synthesis, structure and reactivity of these compounds.

Abstract In 2018, a new class of low‐valent aluminum compound was introduced to the chemical literature. Aluminyl anions [Al (I) (L 2 )] − consist of an Al(I) center supported by a range of (predominantly chelating) dianionic ligand scaffolds, [L 2 ] 2− . The resulting negative charge is balanced by a group 1 metal cation with examples spanning all of the stable alkali metals Li, Na, K, Rb, and Cs. The nature and extent of cation···anion interactions can be controlled, affording three distinct structural types classified as a contacted dimeric pair (CDP), a monomeric ion pair (MIP), or a separated ion pair (SIP). The chemistry of these systems has proven to be very diverse, primarily driven by the oxidation of the aluminum to a more stable Al(III) center. Researchers have been able to harness this thermodynamically favored process to promote a number of different reactions. This article describes the oxidative addition reactions of X–Y sigma bonds to aluminyl anions, to form the corresponding aluminate products [Al (III) (L 2 )(X)(Y)] − , containing examples of new (AlH, AlB, AlC, AlN, AlO, AlF, AlSi, and AlP) bonds. The oxidation of aluminyl anions has been expanded to access compounds with new aluminum–element multiple bonds including examples of AlCR 2 ‐, AlO‐, AlS‐, AlSe‐, AlTe‐, and AlNR‐containing compounds. These terminal bonds react via [2+2] cycloaddition with unsaturated substrates to form new products, demonstrating a preference to react through formally double AlX bonds. Finally, a brief description of the application of aluminyl anions for the reductive coupling of small molecules is included. Examples involving the homocoupling of P 4 ; the homologation of CO; and the dimerization of ketones, isocyanides, and diazomethane are provided. Under favorable conditions, these couplings have been recently extended to include examples of heterocoupling of substrates, demonstrating a high degree of control of product formation.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

This chapter describes the synthesis and reactivity of catena -pnictogen compounds containing (one or more) E E single bonds (E = P, As, Sb, Bi). It is divided into sections describing linear (E) n chains (including dipnictogen compounds where n = 2), monocyclic (E) n ring systems and polycyclic (E) n clusters. The ring systems have been organized according to the size of the ring ( n = 3–6) and whether or not it is associated with a metal fragment (metalated). The section on polycyclic cluster systems begins with a summary of catena -compounds derived from intact or ring-opened P 4 and As 4 starting materials, divided according to the nature of the activating agent ( s - and p -block, d -block or f -block reagents). The concluding sections of the chapter describe the chemistry of polycyclic (E) n clusters derived from other sources.

The chemistry of low valent p-block metal complexes continues to elicit interest in the research community, demonstrating reactivity that replicates and in some cases exceeds that of their more widely studied d-block metal counterparts. The introduction of the first aluminyl anion, a complex containing a formally anionic Al(I) centre charge balanced by an alkali metal (AM) cation, has established a platform for a new area of chemical research. The chemistry displayed by aluminyl compounds is expanding rapidly, with examples of reactivity towards a diverse range of small molecules and functional groups now reported in the literature. Herein we present an account of the structure and reactivity of the growing family of aluminyl compounds. In this context we examine the structural relationships between the aluminyl anion and the AM cations, which now include examples of AM = Li, Na, K, Rb and Cs. We report on the ability of these compounds to engage in bond-breaking and bond-forming reactions, which is leading towards their application as useful reagents in chemical synthesis. Furthermore we discuss the chemistry of bimetallic complexes containing direct Al-M bonds (M = Li, Na, K, Mg, Ca, Cu, Ag, Au, Zn) and compounds with Al-E multiple bonds (E = NR, CR2, O, S, Se, Te), where both classes of compound are derived directly from aluminyl anions.

Orientated ferromagnetic Ni0.89Fe0.11 nanoparticle/polymer nanofibres were made by electmspinning a solution containing iron(III) nitrate nonahydrate, nickel(II) acetate tetrahydrate, polyvinylpyrrolidone, and acetic acid in methanol and thermally processed in Ar and then 95%Ar:5%H-2 up to 620 degrees C. There was a distribution in nanofibre widths after electrospinning with wider (average width 440 nm) and some thinner (average width 120 nm) nanofibres. The nanofibre width distribution decreased after heat treatment and the average nanofibre width reduced to 160 nm. A bimodal Ni0.89Fe0.11 nanoparticle size distribution was found where there were large surface nanoparticles with a mean diameter of 35 nm and small inner nanoparticles with a 5 nm mean diameter. There was a small spin-disordered shell magnetization that was only similar to 2% of the total 5 K saturation magnetization and a characteristic spin-freezing temperature of 21 K. The high field magnetization was large, and it reached 41.7 Am-2/kg at 5 K.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The reduction of Bi(III) and Bi(II) compounds supported by the NONR-ligand (NONR=[O(SiMe2NR)(2)](2-); R=Dipp=2,6-iPr(2)C(6)H(3), tBu) afforded species in which the metal was present in a range of formal oxidation-states. Cyclic voltammetry performed on the Bi(II) radical [Bi(NONDipp)]center dot indicated that the Bi(I) oxidation state was accessible, although the lifetime of the resultant species was short. Preparative scale reactions of Bi(NONDipp)Cl and excess LiBEt3H afforded the tetrametallic cluster Bi-4(NONDipp)(2), in which the bismuth atoms form a [1,2]-edge missing tetrahedron. Reduction of the dibismuthane [Bi(NONtBu)](2) with potassium in the presence of [2.2.2]-cryptand generated a tribismuthinide salt containing the [{Bi(NONtBu)}(2)(mu-Bi)]- anion and a non-coordinating [K([2.2.2]-crypt)](+) cation. Reduction of isolated [Bi(NONDipp)]center dot with the Mg(I) reagent [Mg(BDIDipp)](2) (BDIDipp=[HC{C(Me)NDipp}(2)](-)) formed the dibismuthene [Bi(mu-NONDipp)Mg(BDIDipp)(THF)](2), with a crystallographically verified Bi=Bi multiple bond.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The reduction of Al­(NONDipp)I (NONDipp = [O(SiMe2NDipp)2]2–, Dipp = 2,6-iPr2C6H3) using lithium metal in THF solvent afforded the but-3-enyl-1-oxido product Al­(NONDipp)­(H)­(μ-OCH2CH2CHCH2)­Li­(THF)2. This is the first time that the metalated product of this unusual THF activation pathway has been isolated and structurally characterized.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The terminal antimony phosphanides Sb(NONDipp)(PR2) (NONDipp=[O(SiMe(2)NDipp)(2)](2-); Dipp=2,6-iPr(2)C(6)H(3); R=Cy, Ph) were assessed for catalytic hydrophosphination reactivity. Stoichiometric reactions showed that phenylisocyanate inserts into the Sb-P bond to afford the phosphanylcarboxamidate complex, and subsequent reaction with Cy2P-H confirmed liberation of Cy2PC(O)NHPh. Catalytic hydrophosphination of PhN=C=O by Ph2P-H was demonstrated using 1 mol % catalyst at room temperature. A mixture of mono- and di-insertion products were produced under these conditions.