Ruthenium Carbon-Rich Group as a Redox-Switchable Metal Coupling Unit in Linear Trinuclear Complexes

Charge Transport in Conjugated and Saturated Hydrocarbons: Comparing Ballistic and Cotunneling Contributions

The comparison between electrical transport in CnH2n+2S2 alkane and CnHn+2S2 alkene (n = 4, 6, 8, 10) is studied by using a generalized Breit-Wigner approach and considering coherent transport mechanisms and eventual changes in the state of charge (i.e., cotunneling processes) for both molecules. In general, the conductance of alkanes tends to be smaller than that of similar-sized alkenes. However, cotunneling processes have an important participation in the overall transport in the case of alkanes but not for the alkene family. The progressive changes in both the eigenenergies of the relevant frontier molecular orbitals of the charged species and their spatial localization play decisive roles in the observed differences. While the molecular orbitals of the charged species of the conjugated molecules are hardly affected by the applied voltage, their saturated counterparts are quite sensitive to the external field. With this, successive avoided-crossing events between the molecular orbitals of the single-charged alkane molecules can lead to the appearance of nonballistic conduction channels that make no negligible contributions to the molecular transport.

Heterometal Grafted Metalla-ynes and Poly(metalla-ynes): A Review on Structure-Property Relationships and Applications

Metalla-ynes and poly(metalla-ynes) have emerged as unique molecular scaffolds with fascinating structural features and intriguing photo-luminescence (PL) properties. Their rigid-rod conducting backbone with tunable photo-physical properties has generated immense research interests for the design and development of application-oriented functional materials. Introducing a second d- or f-block metal fragment in the main-chain or side-chain of a metalla-yne and poly(metalla-yne) was found to further modulate the underlying features/properties. This review focuses on the photo-physical properties and opto-electronic (O-E) applications of heterometal grafted metalla-ynes and poly(metalla-ynes).

When Molecular Magnetism Meets Supramolecular Chemistry: Multifunctional and Multiresponsive Dicopper(II) Metallacyclophanes as Proof-of-Concept for Single-Molecule Spintronics and Quantum Computing Technologies?

Molecular magnetism has made a long journey, from the fundamental studies on through-ligand electron exchange magnetic interactions in dinuclear metal complexes with extended organic bridges to the more recent exploration of their electron spin transport and quantum coherence properties. Such a field has witnessed a renaissance of dinuclear metallacyclic systems as new experimental and theoretical models for single-molecule spintronics and quantum computing, due to the intercrossing between molecular magnetism and metallosupramolecular chemistry. The present review reports a state-of-the-art overview as well as future perspectives on the use of oxamato-based dicopper(II) metallacyclophanes as promising candidates to make multifunctional and multiresponsive, single-molecule magnetic (nano)devices for the physical implementation of quantum information processing (QIP). They incorporate molecular magnetic couplers, transformers, and wires, controlling and facilitating the spin communication, as well as molecular magnetic rectifiers, transistors, and switches, exhibiting a bistable (ON/OFF) spin behavior under external stimuli (chemical, electronic, or photonic). Special focus is placed on the extensive research work done by Professor Francesc Lloret, an outstanding chemist, excellent teacher, best friend, and colleague, in recognition of his invaluable contributions to molecular magnetism on the occasion of his 65th birthday.

Dinuclear ruthenium acetylide complexes with diethynylated anthrahydroquinone and anthraquinone frameworks: a multi-stimuli-responsive organometallic switch

The anthrahydroquinone (AHQ)/anthraquinone (AQ) system is of particular interest as a molecular switching system for molecule-based devices because AHQ and AQ can be interconverted by redox stimuli and their π-conjugated systems are distinct from each other. To date, however, a way to modify and/or functionalize the switching behavior based on the AHQ/AQ system is still limited. In the present contribution, the synthesis and properties of multi-responsive dinuclear molecular switches having Ru(dppe)₂ fragments bridged by the diethynylated diacetoxyanthracene (AcAHQ) and AQ units (μ-AcAHQ/AQ){C[triple bond, length as m-dash]C-Ru(R)(dppe)₂}₂ (R = Cl, C₄TMS) are presented. The terminal Ru(dppe)₂ fragments are redox-active and, therefore, the intermetallic interaction can be estimated by electrochemical as well as IVCT band analysis. As a result, the organometallic AcAHQ/AQ-Ru system turns out to be an effective bimodal molecular switch, which is triggered not only by redox stimuli but also by pH stimuli.

Redox-driven porphyrin based systems for new luminescent molecular switches

This work explores the possibility of controlling the fluorescence of porphyrins via oxidation of a ruthenium acetylide unit. The modulation depends on the nature of the porphyrin unit(s).