Exploiting Supramolecular Interactions to Control Isomer Distributions in Reduced-Symmetry [PdL] Cages.

High-symmetry metallosupramolecular architectures (MSAs) have been exploited for a range of applications including molecular recognition, catalysis, and drug delivery. Recently, there have been increasing efforts to enhance those applications by generating reduced-symmetry MSAs. Here we report our attempts to use supramolecular (dispersion and hydrogen-bonding) forces and solvophobic effects to generate isomerically pure [Pd(L)] cage architectures from a family of new reduced-symmetry ditopic tripyridyl ligands.

Can 2-Pyridyl-1,2,3-triazole "Click" Ligands be Used to Develop Cu(I)/Cu(II) Molecular Switches?

Molecular switching processes are important in a range of areas including the development of molecular machines. While there are numerous organic switching systems available, there are far less examples that exploit inorganic materials. The most common inorganic switching system remains the copper(I)/copper(II) switch developed by Sauvage and co-workers over 20 years ago.

6,6'-Ditriphenylamine-2,2'-bipyridine: Coordination Chemistry and Electrochemical and Photophysical Properties.

A 2,2'-bipyridine with bulky triphenylamine substituents in the 6 and 6' positions of the ligand (6,6'-ditriphenylamine-2,2'-bipyridine, 6,6'-diTPAbpy) was generated. Despite the steric bulk, the ligand readily formed bis(homoleptic) complexes with copper(I) and silver(I) ions. Unfortunately, efforts to use the 6,6'-diTPAbpy system to generate heteroleptic [Cu(6,6'-diTPAbpy)(bpy)] complexes were unsuccessful with only the [Cu(6,6'-diTPAbpy)](PF) complex observed.

Cavity-Containing [FeL] Helicates: An Examination of Host-Guest Chemistry and Cytotoxicity.

Two new di(2,2'-bipyridine) ligands, 2,6-bis([2,2'-bipyridin]-5-ylethynyl)pyridine () and bis(4-([2,2'-bipyridin]-5-ylethynyl)phenyl)methane () were synthesized and used to generate two metallosupramolecular [Fe()](BF) cylinders. The ligands and cylinders were characterized using elemental analysis, electrospray ionization mass spectrometry, UV-vis, H-, C and DOSY nuclear magnetic resonance (NMR) spectroscopies. The molecular structures of the [Fe()](BF) cylinders were confirmed using X-ray crystallography.

Self-Assembly of a Redox Active, Metallosupramolecular [Pd L ] Complex Using a Rotationally Flexible Ferrocene Ligand.

A new ferrocene-containing [Pd (L ) ] (X ) (C ⋅ BF and C ⋅ SbF where X=BF or SbF ) self-assembled double-walled triangle has been synthesized from the known, rotationally flexible, 1,1'-bis(4-pyridylethynyl)ferrocene ligand (L ), and characterized by H, C and diffusion ordered (DOSY) NMR spectroscopies, high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), X-ray crystallography and cyclic voltammetry (CV). The molecular structures confirmed that double-walled triangle cage systems (C ⋅ BF and C ⋅ SbF ) were generated. C ⋅ BF was shown to interact with the anionic guest, p-toluenesulfonate.

Redox active [PdL] cages constructed from rotationally flexible 1,1'-disubstituted ferrocene ligands.

Two new ferrocene-containing [Pd(L)](X) (where X = BF or SbF) self-assembled cages (C·BF and C·SbF) were synthesised from the known, rotationally flexible, 1,1'-bis(3-pyridylethynyl)ferrocene ligand (L), and characterised by H, C and diffusion ordered (DOSY) NMR and UV-visible absorption spectroscopies, high resolution electrospray ionisation mass spectrometry (HR-ESI-MS), elemental analysis, X-ray crystallography and cyclic voltammetry (CV). The molecular structures confirmed that cage-like systems (C·BF and C·SbF) were generated. Similar to related [PdL](X), C·SbF was able to interact with a range of neutral and anionic guests, with p-toluenesulfonate showing the strongest association constant.

Anticancer Activity and Cisplatin Binding Ability of -Quinoline and -Isoquinoline Derived [PdL] Metallosupramolecular Cages.

New quinoline ( ) and isoquinoline-based ( ) ligands have been synthesized, along with their respective homoleptic [Pd( or )] cages ( and ). The ligands and cages were characterized by H, C and diffusion ordered (DOSY) NMR spectroscopies, high resolution electrospray ionization mass spectrometry (HR-ESIMS) and in the case of the -quinoline cage, X-ray crystallography. The crystal structure of the architecture showed that the [Pd( )] cage formed a twisted isomer where the [Pd()] units at either end of the cage architecture adopt the opposite twists (left and right handed).

Strategies for Reversible Guest Uptake and Release from Metallosupramolecular Architectures.

The cavities of metallosupramolecular cages can be used to mimic the central spaces of naturally occurring proteins and bind a wide variety of molecular guests. A range of potential applications have arisen from this capacity for host-guest chemistry. However, to truly harness the opportunities thus afforded, methodologies to controllably allow the release and reuptake of guests from the cavities of metallosupramolecular cages are required.

Multicavity Metallosupramolecular Architectures.

Discrete metallosupramolecular systems are often macrocyclic or cage-like architectures with an accessible internal cavity. Guest molecules can reside within these cavities and much of the interest in these systems is derived from these fascinating host-guest interactions. A range of potential applications stem from the ability of these metallosupramolecular architectures to encapsulate guests.

Solid-State Gas Adsorption Studies with Discrete Palladium(II) [Pd (L) ] Cages.

The need for effective CO capture systems remains high, and due to their tunability, metallosupramolecular architectures are an attractive option for gas sorption. While the use of extended metal organic frameworks for gas adsorption has been extensively explored, the exploitation of discrete metallocage architectures to bind gases remains in its infancy. Herein the solid state gas adsorption properties of a series of [Pd (L) ] lantern shaped coordination cages (L = variants of 2,6-bis(pyridin-3-ylethynyl)pyridine), which had solvent accessible internal cavities suitable for gas binding, have been investigated.

Functional metallosupramolecular architectures using 1,2,3-triazole ligands: it's as easy as 1,2,3 "click".

Self-assembled metallosupramolecular architectures have become an increasingly popular area of inorganic chemistry. These systems show a range interesting biological, electronic and photophysical properties. Additionally, they display extensive host-guest chemistry that could potentially be exploited for drug delivery and catalysis.

Oxidatively Locked [Co₂L₃] Cylinders Derived from Bis(bidentate) 2-Pyridyl-1,2,3-triazole "Click" Ligands: Synthesis, Stability, and Antimicrobial Studies.

A small family of [Co₂()₃] cylinders was synthesised from bis(bidentate) 2-pyridyl-1,2,3-triazole "click" ligands () through an "assembly-followed-by-oxidation" method. The cylinders were characterised using ¹H, C, and DOSY NMR, IR, and UV-Vis spectroscopies, along with electrospray ionisation mass spectrometry (ESMS). Stability studies were conducted in dimethyl sulfoxide (DMSO) and D₂O.