Syntheses and molecular structures of half-sandwich iridium metallarectangles containing bridging 2,5-dihydroxy-1,4- benzoquinonato (dhbq) ligands

Modular synthesis of antimalarial quinoline-based PGM metallarectangles

“…The data in Table S2 suggests that the geometry around the iridium metal centre is pseudo-tetrahedral, as the bond angles around the metal centre range between 83.0° and 90.4°. Furthermore, the Ir 1 -N 1 bond length (2.113(6) Å) is comparable to related iridium(III)-pyridyl complexes, 28,30,53,72 however, the Ir 2A -N 2 and Ir 2B -N 2 bond lengths are slightly longer. 28,30,53 Finally, the quinoline and pyridyl ring systems are not co-planar, as expected, with a torsion angle of 44.3°.…”

“…Furthermore, the Ir 1 -N 1 bond length (2.113(6) Å) is comparable to related iridium(III)-pyridyl complexes, 28,30,53,72 however, the Ir 2A -N 2 and Ir 2B -N 2 bond lengths are slightly longer. 28,30,53 Finally, the quinoline and pyridyl ring systems are not co-planar, as expected, with a torsion angle of 44.3°.…”

“…[21][22][23] The first step toward their synthesis requires synthesizing a stable, pre-organized, bimetallic molecular clip. [22][23][24][25][26][27][28][29][30] Compared to main group metals, which are unpredictable, transition metals are often utilized due to their well-defined and predictable coordination geometries. 31,32 To ensure the formation of a discrete supramolecular architecture, directing ligands such as cyclopentadienyl and arene-based ligands are used to occupy concomitant coordination sites at the octahedral metal centre.…”

“…24,31,33,[35][36][37][38][39] A suitable bifunctional donor, which acts as a bridging ligand, can then coordinate predictably to generate a [2+2] rectangular 2-D architecture. [22][23][24][25][26][27][28][29][30]37 Over the years, metallamacrocyclic supramolecular complexes, containing organometallic rhodium, ruthenium, and iridium half-sandwich fragments, have received a considerable amount of attention due to their myriad of potential applications, 40 including as host-guest, [41][42][43] and drug-delivery systems, [44][45][46][47] and in catalysis. 48 Despite extensive research into the pharmacological activity of small metal-based compounds, investigations into the pharmacological activity of metallosupramolecular coordination compounds have primarily centred on their potential as novel anticancer agents (see selected examples in Fig.…”