Electronic Tuning of the Cycloplatinated(II)-Thiolate Complex throughBorane Interaction in the Secondary Coordination Sphere

Cycloplatinated(II) complexes are one of the noteworthy classes of organoplatinum(II)compounds with impressive photophysical properties that are structurally and electronicallytunable through supporting ligands[۱]. For example, thiolates play important roles in the capacityof tuning both steric and electronic properties of transition metal complexes as supportingligands by coupling strong σ-donating, which would make the metal center more electron-rich(based on the electron-donating ability of the aromatic ring coordinated to the S atom) and hencepromote the luminescence properties of the complexes by increasing the energy of the dd*states[۲].Commonly, the usual modification of a complex is brought on by one or more covalentmodifications to the supporting ligand environment, requiring ground-up synthesis of themodified ligand and complex. But beyond that, postsynthetic addition in order to modify Lewisacid-base interactions is a synthetic strategy that complements covalent modification and tunesthe optical and electrochemical properties of cycloplatinated(II) complexes. This technique oftuning is more rapid and methodical than that offered by the usual covalent substituentmodification[۳].In this work, we're up to demonstrate the concept that boranepyridinethiolate Lewis acid-base interactions in the secondarycoordination sphere can bring about significant and systematic changesin the photophysical properties of cycloplatinated(II) complexes bearingthe ppy (۲-phenylpyridine) as a cyclometalated ligand with the generalformula [Pt(ppy)(κ۱-S-Spy)(PPh۳)], where Spy = ۴-pyridine thiolate andPPh۳ = triphenylphosphine.The complex was titrated with BPh۳as aLewis acid at room temperature and was finallyprimarily identified byNMR, HR ESI-MS, and X-ray crystallography.UV-Vis andphotoluminescence spectroscopies were applied in order toconductphotophysical investigations (Figure ۱), and the obtained results wererationalized with the help of DFT (densityfunctional theory) calculations

کلیدواژه ها:

Cycloplatinated complex ، Photophysical properties ، Thiolate ligand ، Borane