Formation, reactivity, photorelease, and scavenging of NO in ruthenium nitrosyl complexes

March 24, 2020

Title

Formation, reactivity, photorelease, and scavenging of NO in ruthenium nitrosyl complexes

Author

Bashnubasu Giri, Sadananda Kumbhakar, K. Kalai Selvan, Arabinda Muley, Somnath Maji

Year

2020

Journal

Inorganica Chimica Acta

Abstract

The two newly designed nitrosyl complexes with Enemark–Feltham notation {RuNO}6 and {RuNO}7 configurations have been isolated as the perchlorate salts in the molecular framework [RuII(dmdptz)(phen)(NO)]n+ (dmdptz: N,N-dimethyl-4,6-di(pyridin-2-yl)-1,3,5-triazin-2-amine and phen: 1,10-phenanthroline) [RuII(dmdptz)(phen)(NO+)](ClO4)3 [4](ClO4)3 and [RuII(dmdptz)(phen)(NO)](ClO4)2 [5](ClO4)2 respectively. The single crystal X-ray structures of complexes [RuII(dmdptz)(phen)Cl](ClO4) [1](ClO4), [RuII(dmdptz)(phen)(NO2)](ClO4) [3](ClO4) and [4](ClO4)3 have been determined. The π– acceptance of the NO+ moiety in [4](ClO4)3 is reflected from the triple bond characteristic bond length 1.131(5) Å with simultaneous trans angle of 175.3(4)° as a proof of true linear coordination mode. A sizable shift in ν (NO) frequency (Δν = 361 cm−1) on moving from [4](ClO4)3 to [5](ClO4)2 are in good agreement for largely NO centered reduction with the changes in bonding {RuNO}6 [4](ClO4)3 to {RuNO}7 [5](ClO4)2. The redox properties of [4](ClO4)3 along with the precursor complexes, have been investigated. On exposure to visible light in the deoxygenated acetonitrile solution at room temperature both [4](ClO4)3 and [5](ClO4)2 spontaneously transform to their corresponding solvated derivative [RuII(dmdptz)(phen)(CH3CN)](ClO4)2 [2](ClO4)2 via the facile photocleavage of Ru–NO bond with KNO 9.26 × 10−3 min−1 (t1/2 = 74 min) and 4.03 × 10−2 min−1 (t1/2 = 17 min) respectively. The photoreleased “NO” can be scavenged by biologically relevant target molecule myoglobin as an MbNO adduct.

Instrument

V-730

Keywords

Absorption, Coordination chemistry, Ligand binding, Inorganic chemistry