Self-Assembly and Redox Modulation of the Cavity Size of an Unusual Rectangular Iron Thiolate Aryldiisocyanide Metallocyclophane

Coordination-Driven Self-Assembly of Cyclometalated Iridium Squares Using Linear Aromatic Diisocyanides

Here, we demonstrate facile [4 + 4] coordination-driven self-assembly of cyclometalated iridium(III) using linear aryldiisocyanide bridging ligands (BLs). A family of nine new [Ir(C^N)₂(μ-BL)]₄⁴⁺ coordination cages is described, where C^N is the cyclometalating ligand-2-phenylpyridine (ppy), 2-phenylbenzothiazole (bt), or 1-phenylisoquinoline (piq)-and BL is the diisocyanide BL, with varying spacer lengths between the isocyanide binding sites. These supramolecular coordination compounds are prepared via a one-pot synthesis, with isolated yields of 40-83%. ¹H NMR spectroscopy confirms the selective isolation of a single product, which is affirmed to be the M₄L₄ square by high-resolution mass spectrometry. Detailed photophysical studies were carried out to reveal the nature of the luminescent triplet states in these complexes. In most cases, phosphorescence arises from the [Ir(C^N)₂]⁺ nodes, with the emission color determined by the cyclometalating ligand. However, in two cases, the lowest-energy triplet state resides on the aromatic core of the BL, and weak phosphorescence from that state is observed. This work shows that aromatic diisocyanide ligands enable coordination-driven assembly of inert iridium(III) nodes under mild conditions, producing supramolecular coordination complexes with desirable photophysical properties.

Redox-Induced Hydrogen Bond Reorientation Mimicking Electronic Coupling in Mixed-Valent Diruthenium and Macrocyclic Tetraruthenium Complexes

We present the coordination-driven self-assembly of three tetranuclear metallacycles containing intracyclic NH₂, OH, or OMe functionalities through the combination of various isophthalic acid building blocks with a divinylphenylene diruthenium complex. All new complexes of this study were characterized by means of nuclear magnetic resonance spectroscopy, ultrahigh-resolution ESI mass spectrometry, cyclic and square wave voltammetry and, in two cases, X-ray diffraction. The hydroxy functionalized macrocycle 4-BOH and the corresponding half-cycle 2-OH stand out, as their intracyclic OH···O hydrogen bonds stabilize their mixed-valent one- (2-OH, 4-BOH) and three-electron-oxidized states (4-BOH). Despite sizable redox splittings between all one-electron waves, the mixed-valent monocations and trications do not exhibit any intervalence charge-transfer band, assignable to through-bond electronic coupling, but nevertheless display distinct IR band shifts of their charge-sensitive Ru(CO) tags. We ascribe these seemingly contradicting observations to a redox-induced shuffling of the OH···O hydrogen bond(s) to the remaining, more electron-rich, reduced redox site.

Formation of iron(iii)–thiolate metallocyclophane using a ferrocene-based bis-isocyanide

Ferrocene-based iron–thiolate complexes are reported, and the kinetic product transforms to its corresponding thermodynamic product by the chelating effect of Fc(NC)₂.

A symmetry interaction approach to [M2L2]4+ metallocycles and their self-catenation

A symmetry interaction approach to [M₂L₂]⁴⁺ metallocycles and their self-catenanes.

Synthesis of carboxylate-bridged iron-thiolate clusters from alcohols/aldehydes or carboxylate salts

A series of novel carboxylate-bridged cyclopentadienyl diiron complexes [Cp*Fe(μ-SEt)2(μ-η(2)-OOCR)FeCp*][PF6] (, R = H; , R = Me; , R = Et; , R = Pr-n; , R = Ph; , R = p-Me-C6H4; , R = PhCH[double bond, length as m-dash]CH; , CH[triple bond, length as m-dash]C) were obtained from alcohols/aldehydes or sodium carboxylates at room temperature. These eight complexes were fully characterized by spectroscopy, and some of them (, , and ) were further studied by X-ray crystallography. In addition, the electrochemical properties of clusters and are also discussed.

Metal-driven self-assembly: the case of redox-active discrete architectures

The growing family of redox-active rings and cages prepared using the coordination-driven self-assembly strategy is reviewed.

A Self-Assembled Electro-Active M8L4 Cage Based on Tetrathiafulvalene Ligands

Two self-assembled redox-active cages are presented. They are obtained by coordination-driven self-assembly of a tetra-pyridile tetrathiafulvalene ligand with cis-M(dppf)(OTf)₂ (M = Pd or Pt; dppf = 1,1′-bis(diphenylphosphino)ferrocene; OTf = trifluoromethane-sulfonate) complexes. Both species are fully characterized and are constituted of 12 electro-active subunits that can be reversibly oxidized.

Construction of covalent- and hydrogen-bonded assemblies from 1′,1′′′-biferrocenediboronic acid as a new organobimetallic building block

Covalent- and hydrogen-bonded assemblies were constructed from 1′,1′′′-biferrocenediboronic acid as a new organobimetallic building block.