Photoinduced Reductive C-O Couplings from Unsymmetrical Bis-Cyclometalated Pt(IV) Dicarboxylato Complexes.

Unsymmetrical bis-cyclometalated dicarboxylato complexes (-6-32)-[Pt(tpy)(OCR)] [tpy = cyclometalated 2-(-tolyl)pyridine, R = -Bu (), Me (), Ph (), CF ()], are obtained from the reaction of -[Pt(tpy)] with the appropriate PhI(OCR) reagent. Treatment of complexes of this type with different carboxylates (R'CO) results in the formation of mixed-carboxylato derivatives, namely (-6-43)-[Pt(tpy)(OCMe)(OCR')] [R' = -Bu (), CF (), Ph ()], (-6-34)-[Pt(tpy)(OCCF)(OCR')] [R' = -Bu (), Me (), Ph ()], and (-6-34)-[Pt(tpy)(OC--Bu)(OCMe)] (). Irradiation of - and - with UV light (365 nm) in MeCN gives 5-methyl-2-(2-pyridyl)phenyl pivalate (), 5-methyl-2-(2-pyridyl)phenyl acetate () or 5-methyl-2-(2-pyridyl)phenyl benzoate () as the major photoproduct from most complexes, resulting from a reductive C-O coupling between a tpy ligand and a carboxylato ligand.

Synthesis, Luminescence, and Electrochemistry of Tris-Chelate Platinum(IV) Complexes with Cyclometalated N-Heterocyclic Carbene Ligands and Aromatic Diimines.

Dicationic, -symmetrical, tris-chelate Pt(IV) complexes of general formula [Pt(trz)(N∧N)](OTf), bearing two cyclometalated 4-butyl-3-methyl-1-phenyl-1-1,2,3-triazol-5-ylidene (trz) ligands and one aromatic diimine [N∧N = 2,2'-bipyridine (bpy, ), 4,4'-di--butyl-2,2'-bipyridine (dbbpy, ), 4,4'-dimethoxi-2,2'-bipyridine (dMeO-bpy, ), 1,10-phenanthroline (phen, ), 4,7-diphenyl-1,10-phenanthroline (bphen, ), dipyrido[3,2-:2',3'-]phenazine (dppz, ), or 2,3-diphenylpyrazino[2,3-][1,10]phenanthroline (dpprzphen, )] are obtained through chloride abstraction from [PtCl(trz)] () using AgOTf in the presence of the corresponding diimine. Complexes show long-lived phosphorescence from LC excited states involving the diimine ligand, with quantum yields that reach 0.18 in solution and 0.

A Novel Substituted Benzo[]quinoxaline-Based Cyclometalated Ru(II) Complex as a Biocompatible Membrane-Targeted PDT Colon Cancer Stem Cell Agent.

Herein, we describe and investigate biological activity of three octahedral ruthenium(II) complexes of the type [Ru(CN)(phen)], -, containing a π-expansive cyclometalating substituted benzo[]quinoxaline ligand (CN ligand) (phen = 1,10-phenanthroline). Compounds - in cervical, melanoma, and colon human cancer cells exhibit high phototoxicity after irradiation with light (particularly blue), with the phototoxicity index reaching 100 for the complex in most sensitive HCT116 cells. accumulates in the cellular membranes.