Order in disorder: solution and solid-state studies of [MM] wheels (MIII = Cr, Al; MII = Ni, Zn)

Heterometallic Al6Zn12 nano-plate with π-conjugated ligand: synthesis and nonlinear absorption properties

Presented herein is the synthesis, structure, and optical properties of the aluminum(III)-zinc(II) heterometallic compound AlOC-57. This compound was found to form a large unit cell (approximately sixteen thousand atoms) and a three-shell nano-plate structure. Based on the Z-scan patterns, the third-order nonlinear optical response of the heterometallic nano-plate was mainly attributed to its nonlinear absorption (reverse saturable absorption).

[(VIVO)2M] (M = Ni, Co) Anderson wheels

Heterometallic Anderson wheels of formula [(VIVO)2MII5(hmp)10Cl2](ClO4)2·2MeOH (M = Ni, 1; Co, 2) have been synthesised from the solvothermal reaction of M(ClO4)2·6H2O and VCl3 with hmpH (2-(hydroxymethyl)pyridine). The metallic skeleton describes a centred hexagon, with the two vanadyl ions sitting on opposing sides of the outer ring. Magnetic susceptibility and magnetisation measurements indicate the presence of both ferromagnetic and antiferromagnetic exchange interactions. Theoretical calculations based on density functional methods reproduce both the sign and strength of the exchange interactions found experimentally, and rationalise the parameters extracted.

[CrIII8NiII6]n+ Heterometallic Coordination Cubes

Three new heterometallic [Cr^III₈Ni^II₆] coordination cubes of formulae [Cr^III₈Ni^II₆L₂₄(H₂O)₁₂](NO₃)₁₂ (1), [Cr^III₈Ni^II₆L₂₄(MeCN)₇(H₂O)₅](ClO₄)₁₂ (2), and [Cr^III₈Ni^II₆L₂₄Cl₁₂] (3) (where HL = 1-(4-pyridyl)butane-1,3-dione), were synthesised using the paramagnetic metalloligand [Cr^IIIL₃] and the corresponding Ni^II salt. The magnetic skeleton of each capsule describes a face-centred cube in which the eight Cr^III and six Ni^II ions occupy the eight vertices and six faces of the structure, respectively. Direct current magnetic susceptibility measurements on (1) reveal weak ferromagnetic interactions between the Cr^III and Ni^II ions, with J_Cr-Ni = + 0.045 cm^-1. EPR spectra are consistent with weak exchange, being dominated by the zero-field splitting of the Cr^III ions. Excluding wheel-like structures, examples of large heterometallic clusters containing both Cr^III and Ni^II ions are rather rare, and we demonstrate that the use of metalloligands with predictable bonding modes allows for a modular approach to building families of related polymetallic complexes. Compounds (1)-(3) join the previously published, structurally related family of [M^III₈M^II₆] cubes, where M^III = Cr, Fe and M^II = Cu, Co, Mn, Pd.

The distribution of reactive Ni2+ in 2D Mg2−xNixAl-LDH nanohybrid materials determined by solid state 27Al MAS NMR spectroscopy

The distribution of Ni²⁺ in paramagnetic Mg_2−xNi_xAl layered double hydroxides obeys a binomial distribution according to ²⁷Al MAS NMR spectroscopy.

Cages on a plane: a structural matrix for molecular ‘sheets’

A family of heterometallic Anderson-type ‘wheels’ of general formula [MIII2MII5(hmp)₁₂]⁴⁺ has been extended to include M^III = Cr, Al; M^II = Co, Ni, Fe, Mn, Cu and Zn, alongside the ‘extended’ [AlIII6CuII7(OH)₁₂(hmp)₁₂]⁸⁺.