Nitrosylpentamminecobalt(II) Chloride, Black, and Nitrosylpentamminecobalt(III) Chloride, Pink

Determination of Equilibrium Constants for Reactions between Nitric Oxide and Ammoniacal Cobalt(II) Solutions at Temperatures from 298.15 to 309.15 K and pH Values between 9.06 and 9.37 under Atmospheric Pressure in a Bubble Column

“…As mentioned above, high temperature (room temperature or above) favors the formation of a red series nitrosyl compound. 22,24 Many previous investigations proved the molecular structure of the red series as μ-hyponitrite dimeric formulation [(NH 3 ) 5 Co(NO) 2 Co(NH 3 ) 5 ] 4+ from various aspects. Feltham 28 reported that the red salt was a 4:1 electrolyte in the form of [(NH 3 ) 5 Co(NO) 2 Co(NH 3 ) 5 ]X 4 by conductivity measurement.…”

“…It has been well accepted that there were two series of cobalt nitrosyl: the black series formed at low temperature (273.15 K and below) and the red series at high temperatures (room temperature or above). 24 Almost all of the researchers who considered isomerization believed that the red isomer was the dicobalt μ-hyponitrite complex with a formula of [(NH 3 ) 5 Co(NO) 2 Co(NH 3 ) 5 ] 4+22, 28,31,32,34,36,37 with only one exception. 38 Because the experimental results showed that an ammoniacal cobalt(II) solution was a promising option for NO abatement, it is of importance to determine its corresponding equilibrium constants for the understanding of NO absorption mechanism.…”

“…Additionally, a number of studies on the preparation − and structure ,,− of cobalt nitrosyl by a reaction between NO and ammoniacal cobalt(II) complexes have been conducted. It has been well accepted that there were two series of cobalt nitrosyl: the black series formed at low temperature (273.15 K and below) and the red series at high temperatures (room temperature or above) .…”

“…Additionally, a number of studies on the preparation − and structure ,,− of cobalt nitrosyl by a reaction between NO and ammoniacal cobalt(II) complexes have been conducted. It has been well accepted that there were two series of cobalt nitrosyl: the black series formed at low temperature (273.15 K and below) and the red series at high temperatures (room temperature or above) . Almost all of the researchers who considered isomerization believed that the red isomer was the dicobalt μ-hyponitrite complex with a formula of [(NH 3 ) 5 Co(NO) 2 Co(NH 3 ) 5 ] 4+ ,,,,,, with only one exception …”