Supramolecular squares of dirhodium(ii) tetracarboxylate: combining carboxylate-exchange and metal–ligand coordination for self-assembly

Abstract

Square self-assemblies are obtained from dirhodium(II) tetracarboxylate complexes using an isonicotinate-type ligand to act as an equatorial ligand to one dirhodium unit and an axial ligand to another. It is shown that the supramolecular squares are formed selectively out of a number of possible compounds in the dynamic carboxylate exchange library.

Coordination-Induced Self-Assembly of a Heteroleptic Paddlewheel-Type Dirhodium Complex

“…A considerable number of experimental and theoretical studies have adequately evaluated the synthesis, molecular geometries, and electronic structures of homoleptic Rh 2 complexes with the same bridging carboxylate ligands, [Rh 2 (O 2 CR) 4 L 2 ] (O 2 CR = bridging carboxylate ligand, L = axial coordinated ligand) [1, [15][16][17][18][19][20][21]. However, heteroleptic Rh 2 complexes with mixed bridging carboxylate ligands, [Rh 2 (O 2 CR) n (O 2 CR') 4-n L 2 ] (n = 1-3), are very limited [22,23]; thus, related research is also insufficient.…”

Tetracarboxylate Ligands as New Chelates Supporting Copper(II) Paddlewheel-Like Structures

“…9 A suitably designed tetracarboxylate ligand could, in principle, strongly stabilize the paddlewheel structure, acting as a tetrabridging ligand and allowing synthesis of paddlewheel complexes with metals other than the traditional ions (Mo(II), Rh(II), and Cu(II)). 30,31 This article reports the synthesis of two new tetracarboxylate ligands conceived with this in view and reports their chemistry with copper(II).…”

Synthesis of discrete Re(i) di- and tricarbonyl assemblies using a [4 × 1] directional bonding strategy

“…13 More recently, Hightower et al have prepared a series of meridionally-coordinated tridentate terpyridine Re(I) dicarbonyl complexes, which showed enhanced absorption through the entire visible portion of the electromagnetic spectrum. 14 Extrapolation of the binding motif mentioned above leads to the self-assembly of two novel Re(I) squares using the directional bonding approach in which the donor and acceptor are located on the same building block, 15 leading to [4 × 1] assemblies instead of the traditional [2 + 2] or [4 + 4] squares. Both the 4-pytpy (4-pytpy = 4′-(4′-pyridyl)-2,2′:6′,2″terpyridine) ligand and Re(I) complexes 1-4 were prepared in average to good yield using methodologies described in the literature (Scheme 1).…”