Discrete Supramolecular Stacks Based on Multinuclear Tweezer‐Type Rhodium Complexes

Guo, Beibei; Azam, Mohammad; Al‐Resayes, Saud I.; Lin, Yue‐Jian; Jin, Guo‐Xin

doi:10.1002/chem.201904580

Cited by 6 publications

(3 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Their relative ease of synthesis has enabled the development of a wide variety of quinoxaline-based ligands that can act as bi- or multidentate donors for different metal ions . Of relevance to the current work, 2-phenylquinoxaline (2-pqx, Scheme ) and its derivatives have been shown to be very effective cyclometalating (C^N) ligands for Ru, Rh, Ir, and Pt . Of these, the studies on Ir(III) species dominate in number, many of which have been undertaken in the past few years.…”

Section: Introductionmentioning

confidence: 99%

Polysubstituted Ligand Framework for Color Tuning Phosphorescent Iridium(III) Complexes

et al. 2021

View full text Add to dashboard Cite

A series of ligands have been synthesized based upon a polysubstituted 2-phenylquinoxaline core structure. These ligands introduce different combinations of fluorine and methyl substituents on both the phenyl and quinoxaline constituent rings. The resultant investigation of these species as cyclometalating agents for Ir(III) gave cationic complexes of the form [Ir(C^N) 2 (bipy)]PF 6 (where C^N = cyclometalating ligand; bipy = 2,2′-bipyridine). X-ray crystallographic studies were conducted on four complexes and each revealed the expected distorted octahedral geometry based upon a cis-C,C and trans-N,N ligand arrangement at Ir(III). Supporting computational studies predict that each of the complexes share the same general descriptions for the frontier orbitals. TD-DFT calculations suggest MLCT contributions to the lowest energy absorption and a likely MLCT/ILCT/LLCT nature to the emitting state. Experimentally, the complexes display tunable luminescence across the yellow-orange-red part of the visible spectrum (λ em = 579−655 nm).

show abstract

Section: Introductionmentioning

confidence: 99%

Polysubstituted Ligand Framework for Color Tuning Phosphorescent Iridium(III) Complexes

et al. 2021

View full text Add to dashboard Cite

show abstract

“… [25] Quinoxalines can be synthesized using a range of differing approaches and materials. [26] This has provided quinoxaline‐based ligands that can act as chelators for a variety of different metal ions [27] including a few examples as cyclometalating (C^N) ligands for Ru, [28] Rh, [29] Ir [30] and Pt. [31] The current series of 2‐phenylquinoxaline ligands ( HL 1–6 ) were designed to allow incorporation of either OCF 3 or CF 3 substituents onto the different phenyl ring positions.…”

Section: Resultsmentioning

confidence: 99%

Organometallic Platinum(II) Photosensitisers that Demonstrate Ligand‐Modulated Triplet‐Triplet Annihilation Energy Upconversion Efficiencies

Fitzgerald

Xiao

Zhao

et al. 2022

Chemistry A European J

View full text Add to dashboard Cite

A series of 2-phenylquinoxaline ligands have been synthesised that introduce either CF 3 or OCF 3 electron-withdrawing groups at different positions of the phenyl ring. These ligands were investigated as cyclometalating reagents for platinum(II) to give neutral complexes of the form [Pt(C^N)(acac)] (in which C^N = cyclometalating ligand; acac = acetyl acetonate). X-ray crystallographic studies on three examples showed that the complexes adopt an approximate square planar geometry. All examples revealed strong PtÀ Pt linear contacts of 3.2041(6), 3.2199(3) and 3.2586(2) Å. The highly coloured complexes display efficient visible absorption at 400-500 nm (ɛ � 5000 M À 1 cm À 1 ) and orange red photoluminescent characteristics (λ em = 603-620 nm; Φ em � 37 %), which were subtly tuned by the ligand. Triplet emitting character was confirmed by microsecond luminescence lifetimes and the photogeneration of singlet oxygen with quantum efficiencies up to 57 %. Each complex was investigated as a photosensitiser for triplet-triplet annihilation energy upconversion using 9,10-diphenylanthracene as the annihilator species: a range of good upconversion efficiencies (Φ UC 5.9-14.1 %) were observed and shown to be strongly influenced by the ligand structure in each case.

show abstract

“…[38] Jin and co-workers employed the halfsandwich [Cp*Rh] moiety as a topological 90°turn-motif in the spine of 16 (Figure 10). [39] The metalloclips adopt semi-rigid structures with only two rotatable RhÀ N bonds in the main skeleton. The large π-surfaces of 16 engage in strong π-π interactions to afford quadruple π-stacks in both solution and solid states.…”

Section: Adaptive Spinesmentioning

confidence: 99%

Assembling Molecular Clips To Build π‐Stacks

Lee,

Lee

2023

Chemistry A European J

View full text Add to dashboard Cite

Nature utilizes an intimate stacking of aromatic motifs to construct functional structures, as demonstrated in protein folding and polynucleotide assembly. However, organized π‐stacks of artificial molecules are difficult to build, primarily due to the weak, non‐directional, and context‐sensitive nature of van der Waals forces. To overcome these challenges, chemists have invented ingenious architectural designs to construct π‐stacked supramolecular assemblies using clip‐like molecules. This CONCEPT article focuses on molecular clips that offer precise spatial control over assembly patterns, beyond the scope of simple host–guest chemistry. We analyze and compare different design strategies that leverage non‐covalent interactions to create multi‐layer π‐stacks. Particular emphasis is placed on the choice of spine units as they play a crucial role in controlling the (i) spacing, (ii) orientation, and (iii) conformational pre‐organization of linked aromatics to achieve long‐range spatial ordering.

show abstract

Discrete Supramolecular Stacks Based on Multinuclear Tweezer‐Type Rhodium Complexes

Cited by 6 publications

References 78 publications

Polysubstituted Ligand Framework for Color Tuning Phosphorescent Iridium(III) Complexes

Polysubstituted Ligand Framework for Color Tuning Phosphorescent Iridium(III) Complexes

Organometallic Platinum(II) Photosensitisers that Demonstrate Ligand‐Modulated Triplet‐Triplet Annihilation Energy Upconversion Efficiencies

Assembling Molecular Clips To Build π‐Stacks

Contact Info

Product

Resources

About