Composites and Materials Prepared from Boron Cluster Anions and Carboranes

Here, we present composites and materials that can be prepared starting with boron hydride cluster compounds (decaborane, decahydro-closo-decaborate and dodecahydro-closo-dodecaborate anions and carboranes). Recent examples of their utilization as boron protective coatings including using them to synthesize boron carbide, boron nitride, metal borides, metal-containing composites, and neutron shielding materials are discussed. The data are generalized demonstrate the versatile application of materials based on boron cluster anions and carboranes in various fields.

Gold(III) Complexation in the Presence of the Macropolyhedral Hydridoborate Cluster [B20H18]2−

Gold(III) complexation with the octadecahydrido-eicosaborate anion [B20H18]2− was studied for the first time. It was found that when gold(III) complexes [Au(L)Cl2]BF4 (L = bipy, phen) reacted with [B20H18]2−, complexes [Au(L)Cl2]2[B20H18] were isolated. The compounds consisted of a cationic gold(III) complex [Au(L)Cl2]+ and the hydridoborate cluster as a counterion. X-ray diffraction studies revealed weak B–H...Au interactions for both compounds. Note that more reactive anions [BnHn]2− (n = 10, 12) in similar reactions with gold(III) complexes resulted in gold mirror reactions.

A new family of one-dimensional bromo-bridged Ir(IV)-Cu(II) complexes based on the hexabromoiridate(IV) metalloligand

By using the iridium(IV) complex (NBu₄)₂[IrBr₆] (1) as a metalloligand towards a Cu(II) metal ion, three novel Ir(IV) one-dimensional (1D) compounds of formula {IrBr₅(μ-Br)Cu(Meim)₄}_n (2), {IrBr₅(μ-Br)Cu(Viim)₄}_n (3) and {IrBr₅(μ-Br)Cu(Buim)₄}_n (4), [Meim = 1-methylimidazole; Viim = 1-vinylimidazole; Buim = 1-butylimidazole] have been prepared and structurally and magnetically characterised. Compounds 2, 3 and 4 crystallise in the triclinic, monoclinic and orthorhombic crystal systems with space groups P1̄, C2/c and Pccn, respectively. Each Ir(IV) ion in 1-4 is six-coordinate and bonded to six bromide ions in a quasi regular octahedral geometry. In compounds 2-4, the Cu^II ion shows an axially elongated octahedron with four N atoms, from four monodentate imidazole derivative ligands, that form the equatorial plane and two bromide ions that occupy the axial positions. Cu(II) and Ir(IV) ions are linked through bridging bromide anions generating Ir(IV)-Cu(II) chains [with intrachain Cu(II)⋯Ir(IV) distances covering the range of ca. 5.10-5.42 Å]. In the crystal lattice of 2 and 3 are observed significant intermolecular Ir-Br⋯Br-Ir contacts and π⋯Br interactions, which organize arrangements that contribute to stabilizing the crystal structure of these Ir(IV)-based compounds. DC magnetic susceptibility measurements reveal that 1 displays magnetic behaviour typical of noninteracting mononuclear centres with S = 1/2. Besides, antiferromagnetic behaviour (2 and 3) and ferromagnetic (4) exchange coupling occur between the Cu(II) and Ir(IV) metal ions in the one-dimensional bromo-bridged compounds 2-4. Moreover, the study of the AC magnetic susceptibility shows a field-induced slow relaxation of the magnetisation for 1, indicating the presence of the single-ion magnet (SIM) phenomenon for the magnetically isolated hexabromoiridate(IV) complex.

Vinylimidazole coordination modes to Pt and Au metal centers

Reaction conditions affect the coordination modes of vinylimidazole to platinum and gold.

Ferromagnetic exchange interaction in a new Ir(iv)–Cu(ii) chain based on the hexachloroiridate(iv) anion

The new chloro-bridged heterobimetallic Ir^IVCu^II chain of formula {IrCl₅(μ-Cl)Cu(viim)₄}_n [viim = 1-vinylimidazole] is the first reported compound based on the Cu^II and Ir^IV metal ions.

[Bis(imidazolyl)-BH2 ]+ [Bis(triazolyl)-BH2 ]- Ionic Liquids with High Density and Energy Capacity

[Bis(imidazolyl)-BH2 ]+ [bis(triazolyl)-BH2 ]- and [bis(imidazolyl)-BH2 ]+ [tris(triazolyl)-BH]- were synthesized, the cations and anions of which were functionalized with B-H groups and azoles. As B-H groups contribute to the hypergolic activity and azole groups improve the energy output, the resulting ionic liquids exhibited ignition delay times as low as 20 ms and energy outputs as high as 461.1 kJ mol-1 . In addition, densities (1.07-1.22 g cm-3 ) and density-specific impulse (≈360 s g cm-3 ) values reached a relatively high level. These ionic liquids show great promise as sustainable rocket fuels.