Reduction of nitrite to NO in an organised triphasic medium by platinum carbonyl clusters and redox active dyes as electron carriers.
Artificial electron donors such as leuco methylene blue and leuco safranin O reduce nitrite ion to nitric oxide. The reaction is effected in a U-tube where nitrite ion and dye in two aqueous layers are separated by a layer of dichloromethane (a close model for a biological liquid membrane) that contains the platinum carbonyl cluster ([Bu(4)N]2[Pt12(CO)24], Chini cluster). On passing dihydrogen an electron transfer chain involving dihydrogen, the dye, the clusters and the nitrite ion is initiated. The cluster catalytically reduces the dye in the presence of dihydrogen, the reduced dye migrates across the phase boundaries and in turn reduces the nitrite ions. The resultant nitric oxide in the effluent gas has been identified by its reactions with cobalamine and myoglobin. When safranin O is the dye, an adduct is formed between the reduced dye and NO. It has been identified by spectroscopic techniques and its probable structure investigated by DFT calculations.
Sen Gupta
Nalinava
N
Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai, 400076, India.
Basu
Susmit
S
Payra
Pramatha
P
Mathur
Pradeep
P
Bhaduri
Sumit
S
Lahiri
Goutam Kumar
GK
D002384:Catalysis; D004396:Coloring Agents; D004578:Electron Spin Resonance Spectroscopy; D004583:Electrons; D005740:Gases / Q000032:analysis; D007202:Indicators and Reagents; D008751:Methylene Blue; D008958:Models, Molecular; D009569:Nitric Oxide / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry*; D010084:Oxidation-Reduction; D017671:Platinum Compounds / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
D004396:Coloring Agents; D005740:Gases; D007202:Indicators and Reagents; D009573:Nitrites; D017671:Platinum Compounds; D009569:Nitric Oxide; D008751:Methylene Blue