Ruthenium nitrosyl complexes with molecular framework [RuII(dmdptz)(bpy)(NO)]n+ (dmdptz: N,N-dimethyl-4,6-di(pyridin-2-yl)-1,3,5-triazin-2-amine and bpy: 2,2'-bipyridine). Electronic structure, reactivity aspects, photorelease, and scavenging of NO

Two mononuclear ruthenium nitrosyl complexes with nitrogen rich ligand coordinated molecular framework [RuII(dmdptz)(bpy)(NO)]n+ (dmdptz: N,N-dimethyl-4,6-di(pyridin-2-yl)-1,3,5-triazin-2-amine and bpy: 2,2'-bipyridine), Enemark and Feltham notation {RuNO}6, [4]3+ (n = 3), and {RuNO}7, [4]2+ (n = 2), have been synthesized by sequential pathways from chloro precursor [RuII(dmdptz)(bpy)(Cl)]+ [1]+ via acetonitrile complex [RuII(dmdptz)(bpy)(CH3CN)]2+ [2]2+ and nitro complex [RuII(dmdptz)(bpy)(NO2)]+ [3]+. Single crystal X-ray structures of [1](ClO4) and [3](ClO4) have been successfully elucidated. Substantial low stretching frequency (NO) band of [4]3+ at 1914 cm due to influence of pyridyl-substituted s-triazine ligand which suggests the moderate electrophilic nature of NO. DFT calculated trans-angle (Ru1N6O1) of 176.713 and 141.745 in [4]3+ and [4]2+ indicate linear and bent coordination mode of NO to central ruthenium respectively. A noticeable shift of  (NO) (solid) ( = 364 cm1) has been observed on moving from [4]3+ to [4]2+ is well accused for NO centered one-electron reduction with {RuNO}6 to {RuNO}7 bonding alteration. The redox properties of [4]3+ have been studied with precursor complexes. Electrochemical conversion of [4]3+ to [3]+ has been performed in presence of 0.5 M NaOH solution. Both [4]3+ and [4]2+ facilitate photocleavage of RuNO bond on exposure with Xenon 200 W visible light source with first order rate constant kNO 8.44 x 10‒3 min‒1 (t1/2 = 82 min) and 4.64 x 10‒2 min‒1 (t1/2 = 15 min) respectively. Light triggered released NO has been captured by biological relevant target protein, reduced myoglobin as MbNO adduct.