1125. The preparation and magnetic susceptibility of nitrosylpentamminecobalt chloride (black)

Bent and Linear {CoNO}8 Entities: Structure and Bonding in a Prototypic Class of Nitrosyls

“…1 Because of its tendency to lose NO upon reversal of its formation, the determination of its magnetism remained ambiguous. 2 In 1971, a redetermination of the crystal structure proved a bent CoNO moiety with the nitrosyl ligand in 4-fold disorder (Co−N−O ca. 119°), although two older X-ray analyses (1965) had found linear CoNO bonding.…”

“…Consequently, it is quite misleading to describe all linear complexes as derivatives of NO + and all bent complexes as derivatives of NO − "). 9 According to Enemark and Feltham, the TBPY-5/SPY-5 transition of an {MNO} 8 species is related to an energetic d(z 2 ) 2 /d(xz) 0 -to-d(z 2 ) 0 /d(xz) 2 crossover along the singlet transition path. Most recently, this Enemark−Feltham scheme was used to illustrate another variable of {CoNO} 8 chemistry, the spin state.…”

“…Historically, a very early exponent of this class was the compound [Co­(NH 3 ) 5 (NO)]­Cl 2 , which was found as a black crystalline solid after the action of NO on concentrated ammonia solutions of cobalt­(II) chloride already in 1903 . Because of its tendency to lose NO upon reversal of its formation, the determination of its magnetism remained ambiguous . In 1971, a redetermination of the crystal structure proved a bent CoNO moiety with the nitrosyl ligand in 4-fold disorder (Co–N–O ca.…”

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

“…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) .…”

Oxygen exchange and acid hydrolysis reactivity of bis(ethylenediamine)oxalatorhodium(III) ion

“…For the conditions of constant acidity which apply to each experimental run in this work, the equilibrium constant expression 8 can be further rearranged to a form which corresponds to the conditions defined by eq 5 K( [IT]2 + [lT]^1) = -c^-t] = (10) This rearrangement enables one to calculate, for each condition of acidity and temperature, a value of k'~\ from the corresponding values of k'i, K, K\, and [H+], Results for these calculations are also given in Table I. /7*, kcal mol"1 AS*, cal mol"1 K"1 24.1 (±2.0) -5.0 (±6.0) *33 18.0 (±2.5) -23.4 (±8.0) 0 ka2 and ka3 defined by eq 11.…”