Cobaltate trans-, sodium

Again, cobalt hydrotricarbonyl probably adds initially. The addition could be either a 1,4-addition or a 1,2-addition in which cobalt initially adds to the second carbon atom of the diene, and then undergoes an allylic rearrangement. The 3-pentenoylcobalt tricarbonyl triphenylphosphine prepared in this manner contains considerably more of the cis isomer than the same compound prepared from trans crotyl bromide and sodium cobalt tetracarbonyl. This, indicates that the hydrocarbonyl prefers cis addition (47). 

Fifty grams of acid-free trcns-diehlorodiethylenediamine-cobalt (III) chloride (No. 131) are dissolved in the minimum of water at 90°C. If the hot green solution is allowed to stand for a short time it begins to turn purple because of hydrolysis to the trans-chloroaquo chloride. To the hot liquid are added 18.5 of anhydrous sodium carbonate and the mixture is stirred until solution is complete. The red liquid is then thoroughly cooled in ice, filtered, and thoroughly drained. 

P-Donors, As-Donors, and Sb-Donors. Formation of purple, diamagnetic [Co(pmm)2-Cl2]+ [pmm = o-C6H4(PMe2)2] has been reported. Further oxidation to cobalt(iv) could not be achieved. Bosnich et al. have reported systematic syntheses for cis- [Co-(das)2X2]"+ (X = Cl, C03, OH2, N02, N03, or MeCN). The ds-[Co(das)2Cl2] + ion was resolved with sodium arsenyltartrate, and the optically active isomers could be converted into other cis-[Co(das)2X2]+ with complete retention of optical activity. It is concluded that the cis - trans isomerization is catalysed by a cobalt(n) species, and this explains the failure to isolate pure cis-Co111 complexes with mildly reducing anions.348... 

Classical methods for the synthesis of frans-dinitro-bis(ethylenediamine)cobalt(III) nitrate involve conversion of the cis isomer by heat1 or action of sodium nitrite on frans-chloronitrobis(othylenediamine)cobalt(III) nitrate.2 These methods involve isolation of intermediate coordination compounds and consequently are subject to low yields, based upon original cobalt(II) salt. The following procedure for the preparation of the trans compound gives an 84% yield it depends upon oxidation of cobalt(II) to cobalt(III) in the presence of sodium nitrite, ethylene-diamine, and nitric acid. 

The configurations of the cis and trans forms of dinitro-bis(ethylenediamine)cobalt(III) ion were established by Werner,4 who resolved the cis form into its optical antipodes. The cis and trans isomers may also be distinguished chemically by utilization of the fact that a warm aqueous 3 % solution of the cis form yields precipitates when treated with concentrated solutions of potassium chromate, ammonium oxalate, or sodium thiosulfate a warm 10% solution of the trans form gives no precipitate with any of these reagents.3... 

Nitrosylpentaamminecobalt(II) chloride, synthesis 49 cts-Bromoamminebis (ethylenediamine) cobal t (111) bromide, CIS- and trans-aquoamminebis(ethylenediamine)cobalt(IIl) bromide, and cis- and triphenylphosphine)rhodium and chloro-carbonylbis(triphenylarsine)rhodium, synthesis 56 Sodium hexachlororhodate(III) 2-hydrate and potassium hexachlororhodate(III) 1-hydrate, synthesis 57 Ammonium hexachloroiridate(IV), synthesis 58 Resolution of the tris(l,10-phenanthroline)nickel(II) ion, synthesis 59... 

The tetraamminedinitrocobalt(lll) salts represent the second longest known case of geometric isomerism among coordination compounds. The reddish-yellow trans compounds were first prepared in 1875 by air oxidation of a solution of cobalt(II) chloride containing ammonia, sodium nitrite, and ammonium chloride by Wolcott Gibbs, who called them croceo salts. The brownish-yellow cis compounds were first prepared in 1894 by reaction of tetraamminecarbonato-cobalt(III) salts with sodium nitrite by Jorgensen, who called them flavo salts. The two series correspond completely to the bis(ethylenediamine)dinitrocobalt-(111) salts. 

C. M. Tourne, G. F. Tourne, E. Zonnevijlle, Chiral polytungstometalates [WM3(H20)2 (XWg034)2] (X = M = zinc or cobalt) and their M-substituted derivatives. Syntheses, chemical, structural and spectroscopic study of some D,L sodium and potassium salts, ]. Chem. Soc. Dalton Trans. (1991) 143. 

Ci,Hi gCoN, Na06S2 3 H2O, Sodium trans-bis(ethylenediamine)disulf ito-cobalt(III) trihydrate, 46B, 942 CftHi gCoN, Oi,P 2.5 H2O, Phosphatobis(ethylenediamine)cobalt (III) hydrate, 43B, 1115... 

CaH,aCl2N2PdS2, Dichlorobis(thiomorpholine)palladium(II), 44B, 9l1 CaH1aCoNgNaOi0 f Sodium trans-dinitro(dimethylglyoximato)(dimethylglyoxime )cobaltate (111) dihydrate, 44B, 912 CaHiaCuNgS2, Thiocyanatotriethylenetetraminecopper(11) thiocyanate, 40B, 1119... 

Cl6H3iCoNsNaOioS, Sodium trans-sulfitobis(dimethylglyoximato)-(aniline)cobaltate(lll) dihydrate, 44B, 994 Cl6H34CI2CUN4O10r (4,4,9,9-Tetramethyl-5,8-diazadodecane-2,11-dione bis(O-methyloxime))copper(II) perchlorate, 44B, 994 Cl8H36N4O4P4S4U, Tetraisothiocyanatotetrakis(trimethylphosphine ox-ide)uranium(lV), 45B, 1256... 

Cobalt complexes [Co en2Cl2]Cl cis Silica gel Methanol-0.5 N sodium acetate in methanol F(cis) > (trans) [15]... 

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