Zur Kenntnis der Sulfito‐kobalt(III)‐Ammine. I. Sulfitopentammin‐ und Sulfitoaquotetramminkobalt(III)‐Salze

Abstract

[CoSO3(NH3)5]+‐Salze reagieren infolge des trans‐Effektes der SO3‐Gruppe bereits mit Wasser unter teilweiser Bildung von [CoSO3H2O(NH3)4]+. In saurem Medium ist die Umwandlung vollständig. Zur Darstellung und Reinigung der Sulfitopentammine muß daher stets in ammoniakalischem Medium gearbeitet werden. Ältere Darstellungsvorschriften, in denen dies nicht beachtet wurde, ergeben Tetrammine oder Pentammin‐Tetrammin‐Gemische. Darstellung und Eigenschaften von [CoSO3(NH3)5]Cl · H2O, [CoSO3(NH3)5]Br · H2O, [CoSO3(NH3)5]J · 1/2 H2O, [CoSO3(NH3)5]ClO4, [CoSO3(NH3)5]2SO4 · 2 H2O und [CoSO3(NH3)5]SCN · H2O werden beschrieben. Ferner werden die bisher nicht erhaltenen Komplexe [CoSO3H2O(NH3)4]Br, [CoSO3H2O(NH3)4]2SO4 und [CoSO3H2O(NH3)4]ClO4 dargestellt. Die Lichtabsorptions‐ und Schwingungsspektren von [CoSO3(NH3)5]+ und [CoSO3H2O(NH3)4]+ werden angegeben und diskutiert.

Thermodynamics for the hydrogenation of dimanganese decacarbonyl

“…There does not appear to be a statistically significant difference between the results obtained with the Co2(CO)g promoter, row 2 of Table III, and the unpromoted reaction, row 1, because the standard deviations for the individual data sets nearly overlap with those from the combined data set, row 3. The standard enthalpy change for the hydrogenation of Mn2(CO)10 in column 2 of Table III is reasonably consistent with a recent determination, 4.0 ± 2.4 kcal/mol, which was measured in toluene solution, based on the enthalpy change for the hydrogen atom transfer reaction in eq 5 and an application of Hess's law.17 As a further check on HMn(CO)5 + Cr(CO)2(PPh3)C5H5 -HCr(CO)2(PPh3)C5H5 + y2Mn2(CO)10 (5) the data, it is noted that the standard entropy change thus obtained for the gas-phase hydrogenation reaction in eq 2, column 3 of Table III, compares favorably to the value, +4.4 ± 0.5 cal/ (mol-K), previously obtained4 for the analogous hydrogenation of eq 1. Furthermore, Ungváry and Markó have obtained 4.4 cal/fmol-K) for the cobalt system of eq 1, although it is noted that this latter value was measured in «-heptane solvent and may not be directly comparable to the gas-phase values obtained in supercritical carbon dioxide.…”

“…because it is an industrially used hydroformylation catalyst. 5 In contrast, the thermodynamics for the analogous manganese system of eq 2 has not been previously determined, despite the prominent role that HMn(CO)5 has played in studies of olefin hydrogenation by hydrogen atom transfer.6…”

Effects of sulfur dioxide, bisulfite(1-), and sulfite(2-) as auxiliary ligands on the reactivity of ammineruthenium(II)-ligand bonds

“…In Table II are recorded, also, data for the rate of substitu tion by pyrazine at pH 8.35 for a variety of temperatures. Since at this pH the Ru(II) complex is essentially completely converted to the sulfito form, the data can be used to calculate the activation parameters for the process frarcs-[Ru(NH3)4(S03)H20] + pz = frazzs-[Ru(NH3)4(S03)pz] + H20 (5) The values of AH^sq^a nd 5*8 3 obtained applying the Eyring equation to the data are 16.3 ± 0.8 kcal mol"1 and 0.8 ± cal mol"1 deg"1.…”

A Structurally Characterised Pair of Dicobalt(III) Peroxo/Superoxo Complexes withC2-Symmetrical Tetrapodal Pentadentate Amine Ligands, and Some Reactivity en route

“…[52] The observed formation of 13 contrasts with the classical synthesis of cobalt(III) S-sulfito amine complexes, in which the SO 3 2Ϫ ligand is introduced in the form of sodium disulfite (Na 2 S 2 O 5 ), which hydrolyses rapidly on dissolving in water to give an equilibrium mixture of SO 2 /HSO 3 Ϫ /SO 3 2Ϫ . [53,54] Cobalt(III) S-sulfito amine complexes have been studied in detail because of the particularly strong kinetic and structural trans effect exerted by the SO 3 2Ϫ ligand, [53,55Ϫ59] a phenomenon which causes some of the compounds to have unusual catalytic [60] and redox properties. [52,60] …”