Structural, Spectroscopic, and Photochemical Investigation of an Octahedral NO-Releasing {RuNO} 7 Species

OSA CODESIDO, N.; SEGANTIN GASPARI, A. P:; SLEP, L. D.; BILL, E.; DA SILVA, R. S.; LEVIN, N.; WEYHERMULLER, T.; OLABE, J. A.

INORGANIC CHEMISTRY

AMER CHEMICAL SOC

Lugar: Washington; Año: 2016 vol. 55 p. 7808 - 7810

0020-1669

[Ru(Me3[9]aneN3)(bpy)(NO)](BF4)2 ([1](BF4)2) was explored by single-crystal X-ray diffrac- tometry, leading to the first crystal structure of an octahedral {RuNO}7 complex. The metal resides on the center of a distorted octahedron, with dN−O and ∠Ru−N− O at 1.177(3) Å and 141.6(2)°, respectively. [1](BF4)2 can be stored indefinitely under argon. Solutions of [1]2+ show no signs of decomposition when protected from air and light. The electron paramagnetic resonance X-band spectrum at 85 K in vitrified acetonitrile (MeCN) shows signals consistent with an S = 1/2 spin state, better described as RuIINO? (g = [2.030, 1.993, 1.880] and A = [11.0, 30.4, 3.9]/10−4 cm−1). In water, the {RuNO}7 species reacts with O2 in a 1:4 stoichiometry. The reaction is first-order in both reactants with k = (1.9 ± 0.2)M−1 s−1 at 25 °C(ΔH⧧ = 11.5 ± 0.3 kJ mol−1; ΔS⧧ = −189 ± 1J K−1 mol−1). Solutions of [1]2+ evolve NO when irradiated a 365 nm with ϕNO = 0.024 and 0.090 mol einstein−1 in H2O and MeCN, respectively