Decorated Tetrathiafulvalene‐Based Ligands: Powerful Chemical Tools for the Design of Single‐Molecule Magnets

Abstract

Invited for the cover of this issue is the group of Fabrice Pointillart and collaborator from Université de Rennes 1, Rennes, France. The cover image illustrates the implication of a tetrathiafulvalene‐based ligand library in the design of single‐molecule magnets.

Interplay of Electronic and Geometric Structure Tunes Organic Biradical Character in Bimetallic Tetrathiafulvalene Tetrathiolate Complexes

“…Since first being reported in the early 1970s, 1-3 tetrathiafulvalene (TTF) has been established as a valuable building block in multiple areas of chemistry and materials science. [4][5][6][7][8][9][10][11][12][13] This includes the use of TTF and its derivatives in organic conductors, 6,10,13,14 metal or covalent organic frameworks, [15][16][17] molecular switches, 5,18 coordinating ligands in transition metal and lanthanide chemistry 4,[19][20][21][22][23][24] and macrocyclic and supramolecular structures. 7,25,26 The versatility in its applications arises from its tunable electronic structure, namely its extended π-system that yields low-lying excitations and accessible 1+ and, more recently, 2+ oxidation states.…”

“…7,25,26 The versatility in its applications arises from its tunable electronic structure, namely its extended π-system that yields low-lying excitations and accessible 1+ and, more recently, 2+ oxidation states. 14,27 Promising applications of TTF-derived compounds include their roles in the development of single molecule magnets (SMM), 21,23 molecular transistors, 28 as well as materials for light harvesting and solar energy conversion. 11 Recently, tetrathiafulvalene tetrathiolate (TTFtt) 29,30 has found application as a bridging ligand in bimetallic transition metal complexes.…”

“…27,31,32 Here TTFtt may be utilized as a formal TTFtt 4− , TTFtt 3− or TTFtt 2− ligand, where the TTF-core is in its neutral, 1+ or 2+ state, respectively, accessed via oxidation of the neutrally charged bimetallic parent compounds 27 . While radical TTF 1+ ligands are well studied and have found applications in the development of SMM, 21,23 the TTFtt 2− ligand has only recently been shown to yield significant TTF-based organic biradical character as a bridging ligand in transition metal bimetallic complexes. 18 Further TTFtt 2− bridged complexes containing different metal centers have been synthesized and demonstrated to display high photoluminescence quantum yield (PLQY), 33 as well as high conductivity in amorphous, glassy coordination polymers.…”

Coordination assemblies based on a flexible tetrathiafulvalene derivative

“…[1][2][3][4][5] To favour the formation of these crystalline architectures, attention has been particularly focused on the use of electro-active ligands such as tetrathiafulvalene (TTF) derivatives. [6][7][8][9][10] The sulfur-rich TTF moiety indeed forms a stable radical cation at accessible redox potentials and can, furthermore, be readily functionalized by a variety of groups such as coordinating units. Carboxylic acids and pyridine groups have been extensively employed for such purposes affording MOFs with appealing physical properties.…”