title: Synthesis, structure, redox, NLO and DNA interaction aspects of [((L'-'")2RuII)3(mu3-L)]3+ and [(L')2RuII(NC5H4S-)]+[L3- = 1,3,5-triazine-2,4,6-trithiolato, L'-'" = arylazopyridine].
abstract: The trinuclear complexes [(L'-'")2RuII)3(mu3-L)](ClO4)3, [1] (ClO4)3-[3](ClO4)3 (L = trianionic form of 1,3,5-triazine-2,4,6-trithiol; N(p)C(5)H(4)N=N(a)-C6H4(R), R = H (L'), m-Me (L"), p-Me (L'")) and the analogous mononuclear complex [(L')2RuII(NC5H4S-)]ClO4 [4] ClO4 were synthesized. Crystal structures of [1](ClO4)3 and [4]ClO4 were determined. [1](3+)-[3](3+) exhibit three successive oxidative couples corresponding to Ru(II)Ru(II)Ru(III)<==>Ru(II)Ru(II)Ru(II); Ru(II)Ru(III)Ru(III)<==>Ru(II)Ru(II)Ru(III); Ru(III)Ru(III)Ru(III)<==>Ru(II)Ru(III)Ru(III) where the mixed valent states are moderately coupled. The complexes display multiple reductions associated with the azo functions of the ancillary ligands (L'-'"). The energy of the Ru(II)-based lowest energy MLCT transitions (533-558 nm) involving the pi* level of azoimine chromophore of L'-'" varies depending on the nuclearity as well as substituents in the ligand framework and follows the order: [1](3+) > [2](3+) > [3](3+) > [4](+). The complexes exhibit reasonably high third-order non-linear optical properties with gamma= (0.90-2.45) [times] 10(-29) esu. The interactions of the trinuclear complexes [((L')2RuII)3(mu3-L)]3+[1]3+, [((bpy)2RuII)3((mu3-L)]3+[5]3+ and [((phen)2RuII)3((mu3)-L)]3+[6]3+(bpy = 2,2'-bipyridine and phen = 1,10-phenanthroline) with the circular and linear forms of p-Bluescript DNA show reduced ethidium bromide fluorescence on gel electrophoresis.
authors.affiliation: Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, India.
authors.forename: Sanjib
authors.initials: S
authors.lastname: Kar
authors.forename: Biswajit
authors.initials: B
authors.lastname: Pradhan
authors.forename: Rajeev Kumar
authors.initials: RK
authors.lastname: Sinha
authors.forename: Tapanendu
authors.initials: T
authors.lastname: Kundu
authors.forename: Prashant
authors.initials: P
authors.lastname: Kodgire
authors.forename: K Krishnamurthy
authors.initials: KK
authors.lastname: Rao
authors.forename: Vedavati G
authors.initials: VG
authors.lastname: Puranik
authors.forename: Goutam Kumar
authors.initials: GK
authors.lastname: Lahiri
mesh_terms: D001391:Azo Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D004270:DNA, Circular / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D004587:Electrophoresis, Agar Gel; D004996:Ethidium / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D010084:Oxidation-Reduction; D010472:Perchlorates / Q000737:chemistry; D010957:Plasmids / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry*; D017975:Ruthenium Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014227:Triazines / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D004270:DNA, Circular; D009942:Organometallic Compounds; D010472:Perchlorates; D011725:Pyridines; D017975:Ruthenium Compounds; D014227:Triazines; D004247:DNA; D004996:Ethidium