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11	Heteroleptic platinum(II) NHC complexes with a C^C* cyclometalated ligand – synthesis, structure and photophysics Tronnier, Alexander, Heinemeyer, Ute, Metz, Stefan, Wagenblast, Gerhard, Muenster, Ingo, Strassner, Thomas 10 January 2020 (has links) Platinum(II) complexes [(NHC)Pt(L)] with various β-diketonate based auxiliary ligands (L: 3-meacac = 3-methylacetylacetonato, dpm = dipivaloylmethanato, dbm = dibenzoylmethanato, mesacac = dimesitoylmethanato, duratron = bis(2,3,5,6-tetramethylbenzoyl)methanato) and a C^C* cyclometalated N-heterocyclic carbene ligand (NHC: dpbic = 1,3-iphenylbenzo[d]imidazol-2-ylidene, dpnac = 1,3-diphenylnaphtho[2,3-d]imidazol-2-ylidene or bnbic = 1-phenyl-3-benzylbenzo[d]imidazol-2-ylidene) were found to show different aggregation and photophysical properties depending on the auxiliary ligand. Eight complexes were prepared from a silver(I)–NHC intermediate by transmetalation, cyclometalation and subsequent treatment with potassium-tert-butanolate and β-diketone. They were fully characterized by standard techniques including ¹⁹⁵Pt NMR. Five complexes were additionally characterized by 2D NMR spectroscopy (COSY, HSQC, HMBC and NOESY). Solid-state structures of five complexes could be obtained and show the tendency of the square-planar compounds to form pairs with different Pt–Pt distances depending on the bulkiness of the substituents at the auxiliary ligand. The result of the photophysical measurements in amorphous PMMA films reveals quantum yields of up to 85% with an emission maximum in the blue region and comparatively short decay lifetimes (3.6 µs). Density functional theory (DFT/TD-DFT) calculations were performed to elucidate the emission process and revealed a predominant ³ILCT/³MLCT character. Organic light-emitting devices (OLEDs) comprising one of the complexes achieved 12.6% EQE, 11.9 lm W⁻¹ luminous efficacy and 25.2 cd A⁻¹ current efficiency with a blue emission maximum at 300 cd m⁻². The influence of an additional hole-transporter in the emissive layer was investigated and found to improve the device lifetime by a factor of seven. info:eu-repo/classification/ddc/540 ddc:540 info:eu-repo/classification/ddc/620 ddc:620 info:eu-repo/classification/ddc/530 ddc:530
12	Development of nonsymmetrical 1,4-disubstituted anthraquinones that are potently active against cisplatin-resistant ovarian cancer cells Teesdale-Spittle, P.H., Pors, Klaus, Brown, R., Patterson, Laurence H., Plumb, J.A. January 2005 (has links) No / A novel series of 1,4-disubstituted aminoanthraquinones were prepared by ipso-displacement of 1,4-difluoro-5,8-dihydroxyanthraquinones by hydroxylated piperidinyl- or pyrrolidinylalkyl-amino side chains. One aminoanthraquinone (13) was further derivatized to a chloropropyl-amino analogue by treatment with triphenylphosphine-carbon tetrachloride. The compounds were evaluated in the A2780 ovarian cancer cell line and its cisplatin-resistant variants (A2780/ cp70 and A2780/MCP1). The novel anthraquinones were shown to possess up to 5-fold increased potency against the cisplatin-resistant cells compared to the wild-type cells. Growth curve analysis of the hydroxyethylaminoanthraquinone 8 in the osteosarcoma cell line U-2 OS showed that the cell cycle is not frozen, rather there is a late cell cycle arrest consistent with the action of a DNA-damaging topoisomerase II inhibitor. Accumulative apoptotic events, using time lapse photography, indicate that 8 is capable of fully engaging cell cycle arrest pathways in G2 in the absence of early apoptotic commitment. 8 and its chloropropyl analogue 13 retained significant activity against human A2780/cp70 xenografted tumors in mice. Treatment resistance Transition metal Complexes Divalent metal Complexes Platinum II Complexes Malignant tumour Alkylating agent Vertebrata Mammalia Rodentia Cell line Chlorine Organic compounds Animal Ovary Tumour cell Human Alcohol Antineoplastic agent Mechanism of action Antimitotic Intraperitoneal administration Chemotherapy Cytotoxicity In vivo Pyrrolidine derivatives Piperidine derivatives Tricyclic compound Condensed benzenic compound Structure activity relation Diphenols Aromatic amine Ovarian cancer In vitro Chemical synthesis Cisplatin

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Heteroleptic platinum(II) NHC complexes with a C^C* cyclometalated ligand – synthesis, structure and photophysics

Development of nonsymmetrical 1,4-disubstituted anthraquinones that are potently active against cisplatin-resistant ovarian cancer cells