Automated Structural Activity Screening of β-Diketonate Assemblies with High-Throughput Ion Mobility-Mass Spectrometry

Embracing complexity in design, metallo-supramolecular self-assembly presents an opportunity for fabricating materials of economic significance. The array of accessible supramolecules is alluring, along with favourable energy requirements. Implementation is hampered by an inability to efficiently characterise complex mixtures. The stoichiometry, size, shape, guest binding properties and reactivity of individual components and combinations thereof are inherently challenging to resolve. A large combinatorial library of four transition metals (Fe, Cu, Ni and Zn), and six β-diketonate ligands at different molar ratios and pH was robotically prepared and directly analysed over multiple timepoints with electrospray ionisation travelling wave ion mobility-mass spectrometry. The dataset was parsed for self-assembling activity without first attempting to structurally assign individual species. Self-assembling systems were readily categorised without manual data-handling, allowing efficient screening of self-assembly activity. This workflow clarifies solution phase supramolecular assembly processes without manual, bottom-up processing. The complex behaviour of the self-assembling systems was reduced to simpler qualities, which could be automatically processed.

Syntheses and Characterization of Main Group, Transition Metal, Lanthanide, and Actinide Complexes of Bidentate Acylpyrazolone Ligands

The synthesis of acylpyrazolone salts and their complexes of main group elements, transition metals, lanthanides, and actinides are described and characterized inter alia by means of single-crystal X-ray crystallography, NMR, and IR spectroscopies. The complexes consist of two, three, or four acylprazolone ligands bound to the metal atom, resulting in a structurally diverse set of coordination complexes with (distorted) octahedral, pentagonal-bipyramidal, or antiprismatic arrangements. Several complexes proved to be polymeric in the solid state including heterobimetallic sodium/lanthanide coordination polymers. A selection of the polymeric compounds was analyzed via TG/DTA measurements to establish their stability. The ligands, in turn, were readily synthesized in good yields from commercially available hydrazine hydrochloride salts. These findings demonstrate that acylpyrazolone ligands can form complexes with metals of varying ionic radii, highlighted by their utility in other areas such as analytical and metal organic framework chemistry.

Charge Neutral [Cu2L2] and [Pd2L2] Metallocycles: Self-Assembly, Aggregation, and Catalysis

A range of morphologically distinct metallosupramolecular Cu(II) and Pd(II) complexes has been constructed, based on the tritopic ligand 1,1',1″-(benzene-1,3,5-triyl)tris(4,4-dimethylpentane-1,3-dione) (H₃L). By control of the reaction conditions, it is possible to generate distinct coordination assemblies possessing either macrocyclic or polymeric structures and more importantly distinct activity in catalysis of the Suzuki-Miyaura cross-coupling.

Dinuclear triple stranded phenyl-spaced 1,3-bis-β-diketonato lanthanide(iii) complexes: synthesis, structures and spectroscopy

The synthesis and crystal structures of a series of Ln(iii) (Ln = Gd, Nd, Yb as well as Y) complexes of a bis-β-diketone ligand incorporating a 1,3-substituted phenyl ring between its two β-diketone domains (1,1'-(1,3-phenylene)bis(4,4-dimethylpentane-1,3-dione), H₂L¹) is reported. The crystal structures show the complexes are seven coordinate in the solid state with the general formula [Ln₂L¹₃(solvent)₂]. The photophysical properties of the complexes were explored in both solution and the solid state, which show an increase in coordination number in solution.

A Two-Dimensional Coordination Polymer Formed from Cobalt(II) and an Extended Dipyridyl Ligand

The synthesis of the extended dipyridyl ligand 4,4′-(2,5-dimethyl-1,4-phenylene)dipyridine (L) in an improved yield via the palladium catalysed Suzuki coupling of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine (1) and 1,4-dibromo-2,5-dimethylbenzene (2) is reported along with its use to form a two-dimensional coordination polymer [Co2L2(OAc)4(H2O)2]n. The coordination polymer consists of one-dimensional chains of octahedral cobalt ions bridged by acetate ligands which are connected to form two dimensional sheets with square lattice (sql) topology via the dipyridyl ligands (L). The structure contains small voids totalling ~6.6% of the unit cell volume. The crystal structures 1, L, L·2H2O, and L·2HNO3 are also reported.