Supramolecular luminescent Pt(ii) tweezers: aggregation studies and ¹O₂ production

Abstract

Four series of Pt(II) tweezer compounds have been designed and synthesized in order to explore their ability to form supramolecular assemblies and influence upon their resulting luminescence. The compounds present...

Effect of substituents on the 1O2 production and biological activity of (N^N^N)Pt(py) complexes

“…23–32 The influence of the apparent innocent chlorine substituent on the resulting emission responsible for the quenching recorded for L 2 -derivatives was also previously observed for other analogous Pt(N^N^N) complexes. 23…”

“…The synthesis of the bis(triazole) N^N^N H 2 L 1 –H 2 L 4 ligands and [Pt(DMSO)( L )] precursors was recently reported by us. 23 The [Pt(DMSO)( L )] compounds were reacted with the p -R 2 -pyridyl ligand (R 2 = CF 3 , CHF 2 and CH 3 ) to obtain the final products in moderate to high yields (45–85%).…”

“…Low-intensity absorption bands at around 325 and 360 nm were recorded for all the compounds (Table 1) that have been assigned to 1 IL and 1 MLCT transitions as reported and studied for similar compounds in the literature. [23][24][25][26][27][28][29][30][31][32] TD-DFT calculations were performed on all complexes to further support the band assignments. We have calculated the first 20 excited states using the CAM-B3LYP/def2-TZVP level of theory in DMSO treated as a continuum model.…”

“…420 nm, which may be ascribed to the formation of some aggregates, as previously observed for the [Pt(N^N^N)(diphos)] complexes recently reported by us based on previous data reported in the literature. 23 The corresponding emissions are ascribed to metal perturbed 1 IL/ 1 MLCT transitions and 3 MLCT/ 3 MMLCT transitions. [23][24][25][26][27][28][29][30][31][32] The influence of the apparent innocent chlorine substituent on the resulting emission responsible for the quenching recorded for L 2 -derivatives was also previously observed for other analogous Pt(N^N^N) complexes.…”

“…23 The corresponding emissions are ascribed to metal perturbed 1 IL/ 1 MLCT transitions and 3 MLCT/ 3 MMLCT transitions. [23][24][25][26][27][28][29][30][31][32] The influence of the apparent innocent chlorine substituent on the resulting emission responsible for the quenching recorded for L 2 -derivatives was also previously observed for other analogous Pt(N^N^N) complexes. 23 The corresponding emission quantum yields corresponding both to the fluorescence and to the phosphorescence band were recorded with low values of 1-2% for the fluorescence being about double for the phosphorescence emission (Table 2).…”