Exploiting host–guest chemistry to manipulate magnetic interactions in metallosupramolecular M₄L₆ tetrahedral cages

Abstract

The tetrahedral [NiII4L6]8+ cage can reversibly bind paramagnetic MX41/2− guests, inducing magnetic exchange interactions between host and guest.

Recent advances and perspectives on supramolecular radical cages

“…14b). 51 Upon illumination, a series of electron-rich alkyl-aromatic hydrocarbons, such as 9-methylanthracene ( 41), 1methylnaphthalene (42), and toluene (43), encapsulated in cage 39b were found to be readily converted to the corresponding neutral benzyl radicals via a water-assisted proton-coupled electron transfer (PCET) process, and thus activated their C-H bonds. Subsequently, the photogenerated long-lived benzyl radical within 39b reacted with O 2 to give the oxidized product.…”

“…11c ). 42 The magnetic exchange interactions of these series host–guest complexes were systematically investigated in their work by SQUID magnetometry, assisted by theoretical studies, disclosing that the magnetic exchange interactions between metal ions in the host complex, and between the host and guest, were of comparable magnitude and antiferromagnetic in nature. The confinement induced anisotropy of paramagnetic Co II guests in this work also highlighted the potential of the supramolecular radical cage in the design of highly unusual/anisotropic single-ion magnets (SIMs).…”

Sterics and metal-ion radius control the self-assembly of [M2L3] helicates

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] For example, while triple-stranded [M 2 L 3 ] helicates [14][15][16][17] have been shown to function as synthetic mimics of α-helices 18 or interact with DNA, 19,20 their guest-binding and catalytic properties are far more restricted than the corresponding [M 4 L 6 ] tetrahedra. [21][22][23][24][25][26][27][28][29][30][31] In order to favour the formation of a [M 2 L 3 ] helicate typically either a ligand with coordination vectors close to parallel or a certain degree of flexibility is employed, while rigid ligands with more divergent coordinating moieties tend to favour [M 4 L 6 ] assemblies. [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] We have r...…”

Guest-induced magnetic exchange in paramagnetic [M2L4]4+ coordination cages

“…12,13 Paramagnetic M 2 L 4 lantern cages are much less well explored, 14 indeed investigations of the magnetic behaviour of any supramolecular cages remains virtually unexplored. 15 However, the host-guest chemistry of these systems offers a range of potential advantages for the exploitation of magnetic materials properties. These include, for example, the reversible inducement of magnetic exchange interactions, the encapsulation of unstable/reactive molecules or those with unusual geometries/coordination numbers, solid-state dilution, and the tuning of magnetic anisotropy.…”