Successive modification of polydentate complexes gives access to planar carbon- and nitrogen-based ligands

Abstract

Polydentate complexes containing combinations of nitrogen and carbon (N and C) ligating atoms are among the most fundamental and ubiquitous molecules in coordination chemistry, yet the formation of such complexes with planar high-coordinate N/C sites remains challenging. Herein, we demonstrate an efficient route to access related complexes with tetradentate CCCN and pentadentate CCCCN and NCCCN cores by successive modification of the coordinating atoms in complexes with a CCCC core. Combined experimental and computational studies reveal that the rich reactivity of metal-carbon bonds and the inherent aromaticity of the metallacyclic skeletons play key roles in these transformations. This strategy addresses the paucity of synthetic approaches to mixed N/C planar pentadentate chelating species and provides valuable insights into the synthesis of carbon-based high-coordinate complexes. Furthermore, the resulting complexes are the examples of organometallic species with combined photoacoustic, photothermal, and sonodynamic properties, which makes them promising for application in related areas.

Metallaaromatic Chemistry: History and Development

“…An 18 O-labeling experiment indicates the oxygen on the newly formed carbonyl comes from the trace amount of H 2 O (Scheme 261). 545 The osmapentalene derivative 810 was further treated with TMSN 3 followed by n-Bu 4 NF, leading to the formation of the CCCN-type tetradentate product 811 (Scheme 261). Experimental data combining with DFT calculations indicate that 811 is non-aromatic.…”

Carbolong Chemistry: Planar CCCCX-Type (X = N, O, S) Pentadentate Chelates by Formal [3+1] Cycloadditions of Metalla-Azirines with Terminal Alkynes

“…Although an expanding variety of complexes with planar bidentate, tridentate, or tetradentate ligands has attracted tremendous research interest, [24][25][26][27][28] the synthesis of planar high-coordination complexes, such as pentadentate complexes, has proven to be very difficult to achieve. [29][30][31] The coordinating atoms in those reported polydentate complexes are primarily drawn from a range of donor heteroatoms including N, O, P, and S. To date, the synthesis of complexes with carbons as the sole principal sites of a pentadentate ligand is very rare, [32][33][34] probably owing to their inaccessible and atypical geometries.…”

Tuning an Electrode Work Function Using Organometallic Complexes in Inverted Perovskite Solar Cells

“…Organometallic materials whose electronic properties could be regulated by altering core metals and chelating ligands offer the potential to modulate the interfaces of photovoltaic devices. Carbolong complexes with strong metal–carbon bonds, which are formed by the chelation of a carbon chain (carbolong ligand) with a transition metal fragment, are a burgeoning class of π-conjugating organometallic frameworks. − Carbolong-derived complexes have emerged as promising materials in many applications due to their excellent photophysical properties. , Recently, an osmium–carbolong complex has been successfully used as an ETL material in OSCs, which had a PCE up to 16.28% …”

“…24−26 Carbolong-derived complexes have emerged as promising materials in many applications due to their excellent photophysical properties. 26,27 Recently, an osmium−carbolong complex has been successfully used as an ETL material in OSCs, which had a PCE up to 16.28%. 28 Herein, we report a series of novel carbolong-derived frameworks that allow low-and high-WF metals to be used as cathodes for PSCs.…”