Improvement of the Photophysical Performance of Platinum‐Cyclometalated Complexes in Halogen‐Bonded Adducts. Issue 44 (3rd July 2018)

• Record Type: Journal Article
• Authors: Sivchik, Vasily; Sarker, Rajib Kumar; Liu, Zong‐Ying; Chung, Kun‐You; Grachova, Elena V.; Karttunen, Antti J.; Chou, Pi‐Tai; Koshevoy, Igor O.
• Is Part Of: Chemistry. Volume 24:Issue 44(2018)
• Page Start: 11475
• Page End: 11484
• Publication Date: 2018-07-03
• Subjects: crystal engineering -- halogens -- luminescence -- noncovalent interactions -- platinum; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201802182
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Three groups of luminescent platinum complexes [Pt(C^N)(L)(Y)] [C^N=benzothienyl‐pyridine (1 ), bezofuryl‐pyridine (2 ), phenyl‐pyridine (3 ); L/Y=DMSO/Cl (a ), PPh3 /Cl (b ), PPh3 /CN (c )] have been probed as halogen‐bond (XB) acceptors towards iodofluorobenzenes (IC6 F5 and I2 C6 F4 ). Compounds1 a and2 a (L/Y=DMSO/Cl) afford the adducts1 a ⋅⋅⋅I2 C6 F4 and2 a ⋅⋅⋅I2 C6 F4, which feature I⋅⋅⋅Sbtpy /I⋅⋅⋅πbtpy and I⋅⋅⋅ODMSO /I⋅⋅⋅Cl short contacts, respectively. The phosphane‐cyanide derivatives1 c and2 c (L/Y=PPh3 /CN) co‐crystallise with both IC6 F5 and I2 C6 F4 . None of the phpy‐based species3 a –3 c participated in XB interactions. Although the native complexes are rather poor luminophores in the solid state (Φem =0.023–0.089), the adducts exhibit an up to 10‐fold increase of the intensity with a minor alteration of the emission energy. The observed gain in the quantum efficiency is mainly attributed to the joint influence of non‐covalent interactions (halogen/hydrogen bonding, π–π stacking), which govern the crystal‐packing mode and diminish the radiationless pathways for the T1 →S0 transition by providing a rigid environment around the chromophore. Abstract : Special addition : Cyclometallated platinum complexes, equipped with a range of electron‐rich functionalities, undergo halogen‐bond‐driven co‐crystallisation with fluorinated iodoarenes to give adducts with different intermolecular arrangements, which display up to ten times higher intensities of phosphorescence than the parent compounds.