Synthesis, DNA-binding and photocleavage studies of ruthenium(II) complexes [Ru(btz)3]2+ and [Ru(btz)(dppz)2]2+

Abstract

Two new ruthenium(Ⅱ) complexes, [Ru(btz) 3 ](ClO 4 ) 2 (1) and [Ru(btz)(dppz) 2 ](ClO4 ) 2 (2) (btz = 4,4′-bithiazole, dppz = dipyrido[3,2-a:2′,3′-c]phenazine), have been synthesized and characterized by elemental analysis, 1 H NMR, ES-MS and X-ray crystallography. The DNA binding behaviors of two complexes have been studied by spectroscopic and viscosity measurements. The results suggest that complex 1 binds to CT-DNA via an electrostatic mode, while complex 2 via an intercalative mode. Under irradiation at 365 nm, both complexes were found to promote the cleavage of plasmid pBR 322 DNA from supercoiled form Ⅰ to nicked form Ⅱ. The mechanism studies reveal that singlet oxygen 1 O 2 and hydroxyl radical (OH • ) play a significant role in the photocleavage process. ruthenium(Ⅱ) complex, DNA binding, DNA photocleavage, PDT

“Rollover” cyclometalation – early history, recent developments, mechanistic insights and application aspects

“…15) was formed, which, upon dissolving in dimethylsulfoxide, converts to [Tl(dmbt À H) 2 (NO 3 )-(dmso)] (39; L ¼ DMSO) (accompanied by some isomerization). 148 Although, in several instances, 4,4 0 -bithiazole was shown to act as an N,N-bidentate ligand, [149][150][151][152][153][154] it is not possible to unambiguously decide if 39 is the outcome of a genuine ''rollover'' cyclometalation process because no N,N-bidentate intermediates were observed. However, when 2,2 0 -diphenyl-4,4 0bithiazole (dpbt) is treated with Tl(NO 3 ), the N,N-bidentate [Tl (dpbt)(NO 3 ) 3 ] complex 40 was formed; 155 this observation may thus suggest that genuine ''rollover'' cyclometalation is also involved in the production of 39.…”

“…148 Although, in several instances, 4,4 0 -bithiazole was shown to act as an N,N-bidentate ligand, [149][150][151][152][153][154] it is not possible to unambiguously decide if 39 is the outcome of a genuine ''rollover'' cyclometalation process because no N,N-bidentate intermediates were observed. However, when 2,2 0 -diphenyl-4,4 0 -bithiazole (dpbt) is treated with Tl(NO 3 ), the N,N-bidentate [Tl (dpbt)(NO 3 ) 3 ] complex 40 was formed;…”

Light-induced spin-state switching in Fe(ii) spin-crossover complexes with thiazole-based chelating ligands

“…Complex 1 crystallizes in the space group C2/c, as reported previously, 5 and is isostructural with the analogous Ni(II) and Ru(II) complexes. 5,11 The asymmetric unit (ASU) contains a half of the [Fe(4bt) 3 ] 2+ cation and one ClO 4 − anion (Fig. S2a †).…”

Microwave assisted synthesis of disubstituted benzyltin arylformylhydrazone complexes: anticancer activity and DNA‐binding properties

“…The target of platinum‐based chemotherapy agents is the DNA in the proliferating cells. Therefore, DNA is an important target for drug design . Many organotin compounds exhibit good binding to DNA .…”