The compounds Co(CF3SO3)2, Cu(CF3SO3)2, Co(CH3SO3)2, Cu(CH3SO3)2, Co(p-CH3C6H4SO3)2, and Cu(p-CH3C6H4SO3)2 have been prepared and infrared spectra, electronic spectra, and magnetic susceptibility studies are reported. Electronic spectral and magnetic studies have also been made on Cu(FSO3)2 and previously published data on Co(FSO3)2 are reexamined here. The studies indicate that in all salts the metal ions are hexacoordinated by oxygen atoms provided by anions acting as tridentate bridging ligands. The MO6 skeleton is significantly distorted from regular octahedral geometry for all salts with the possible exceptions of Co(FSO3)2, Co(p-CH3C6H4SO3)2, and Co(CH3SO3)2. Values of the spin–orbit coupling constants for the salts, as estimated from the magnetic studies, decrease with increasing anion basicity, suggesting a correlation between basicity and the degree of covalent character in the metal–anion bonds. In the case of the cobalt salts the interelectron repulsion parameter B also seems to decrease with increasing anion basicity.

The fractional extent α of decomposition of ripened Ni(OH)2 into green NiO in alkaline hydrothermal conditions under nitrogen is given by the rate law α1/3 = kc[OH−]t, where kc = 2.4 × 10−5 kg mol−1 s−1 at 561 K. The Arrhenius activation energy is 220 + 25 kJ mol−1. The reaction is accelerated moderately by O2 (giving black NiO1+δ) and strongly by added NiO. A reaction mechanism involving dissolution of Ni(OH)2 as Ni(OH)3− (aq) and rate-determining, surface-controlled reprecipitation of this as NiO is proposed.

Der Zersetzungsgrad von gealtertem Ni(OH)2 zu grünem NiO nach A unter alkalisch hydrothermalen Bedingungen unter N2 wird durch das Geschwindigkeitsgesetz α1/3 = kc‐ [OH′]t gegeben (kc = 2.4‐l0′5 kg mol‐1 bei 561 K; Ea = 220 ± 25 kJ mol‐1).

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