Effect of the Chirality of Counter Anions on the Vapochromic Behavior of Luminescent Pt^II Complexes

Abstract

New luminescent PtII complexes with the chiral counter anions [PtCl(tpy)](l‐Hta) (1‐L) and [PtCl(tpy)](dl‐Hta) (1‐DL; tpy = 2,2′:6′,2′′‐terpyridine; l‐H2ta = l‐tartaric acid; dl‐H2ta = racemic tartaric acid) were synthesized and their vapochromic behavior was evaluated. Single crystal X‐ray analysis revealed that the stacked square‐planar PtII molecules in anhydrous 1‐DL formed a one‐dimensional columnar structure with weak intermolecular Pt···Pt interactions, while in anhydrous 1‐L the PtII molecules were dimerized with Pt···Pt interactions to form a zig‐zag stacked column. These differences were attributed to the different hydrogen bonding in the dl‐ and l‐Hta– ions. The dihydrates of 1‐DL and 1‐L displayed near‐identical crystal structures with comparable emission spectra derived from 3π–π* ligand emission. Both dihydrates exhibited MeOH‐vapor‐induced dehydration to form the anhydrous complexes. These presented broad 3MMLCT emission (549 and 565 nm, respectively), affected by the degree of intermolecular Pt···Pt interactions.

Near-infrared vapochromism in lipid-packaged mixed-valence coordination polymers

“…S8, ESI†). Similar MeOH-vapor-induced dehydration phenomena have also been reported for platinum complexes, 26–28 and it is not a particularly rare phenomenon. Upon subsequent re-exposure of the MeOH-treated reddish-brown sample to water vapor, the thermal weight loss was recovered to the original value (∼0.98%, Fig.…”

Phosphorescent Cyclometalated Platinum(II) Enantiomers with Circularly Polarized Luminescence Properties and Their Assembly Behaviors

“…Phosphorescent organoplatinum­(II) complexes have recently been extensively utilized to construct a wide variety of supramolecular materials because of their unique square-planar geometry and propensity to form noncovalent metal–metal interactions, which would render the molecules to aggregate, resulting in intriguing luminescence properties. − For example, drastic color and emission changes are found to occur during the assembly process, which can be attributed to the formation of noncovalent metal–metal and π–π stacking interactions. − In view of the fascinating spectroscopic properties, platinum­(II) complexes with functional ligands have also been exploited as sensors to afford color or phosphorescence changes in response to microenvironmental changes. − The rich and tunable emission colors and high photoluminescence quantum yields have also rendered them promising candidates for the fabrication of organic light-emitting diodes. − Recently, with the upsurge of research focusing on CPL materials, a few examples of platinum­(II) complexes with chiral groups modified on the bidentate or tridentate ligands have been reported with the amplification of CPL from the molecular level to assembled supramolecular architectures. ,− Apart from this, the decoration of ancillary ligands can also alter the solubility, photophysical, and self-assembly properties of platinum­(II) complexes. − Herein, we designed and synthesized a series of cyclometalated 1,3-di­(2-pyridyl)­benzene platinum­(II) complexes modified with different functional groups on the ancillary alkynyl ligands (Scheme ). They are capable of assembling into different aggregates through isodesmic self-assembly processes.…”

Chromic Platinum Complexes Containing Multidentate Ligands

“…Although the effect of vapors in the crystal lattice of 9 could not be elucidated by SCXRD, UV‐vis spectroscopy confirmed the appearance of MMLCT bands upon the uptake of solvent molecules, which proved a decrease in the Pt⋅⋅⋅Pt separation. Similarly, Kato's [70,71] and Sun's [72] groups addressed the effect of counterions in vapochromic Pt(II) complexes.…”