Tris chromate hydroxide

C9H2aCrOsSna, Tris(trimethyltin) chromate hydroxide, 40B, 684 CloH8Cl2N2S2Sn, Dichlorobis(2-pyridinethiolato)tinUV), 44B, 669 C1 oHi oCli,GeN2, trans-Dipyridinetetrachlorogermanium, 24, 619 CioHioPb, Dicyclopentadienyllead, 31B, 332... 

Hydrated forms of the hydroxide ion have been much less well characterized though the monohydrate [H302] has been discovered in the mixed salt Na2[NEt3Me][Cr PhC(S)=N-(0) 3]. NaH302.18H20 which formed when [NEt3Me]I was added to a solution of tris(thiobenzohydroximato)chromate(III) in aqueous NaOH. ° The compound tended to lose water at room temperature but an X-ray study identified the centro-symmetric [HO-H-OH] anion shown in Fig. 14.15. The central O-H-O bond is very short indeed (229 pm) and is... 

Malonic acid CH2(C02H)2 (H2mal) (209) has a coordination chemistry with chrommm(III) closely resembling that of oxalate. Malonic acid is a slightly weaker acid than oxalic acid and slightly more labile complexes are formed. The tris complex is the most extensively studied, prepared by the reduction of chromate solutions or the reaction of chromium(III) hydroxide with malonate.917,918 919 The cis and trans diaqua complexes may be prepared by the reduction of chromate with malonate the isomers are separated by fractional crystallization. The electronic spectrum of the tris complex is similar to that of the tris oxalate and a detailed analysis of these spectra has appeared.889... 

Potassium tris(malonato)chromate(IIl) trihydrate can be prepared by the method of Lapraik, reacting freshly precipitated chromium(III) hydroxide with malonic acid and potassium carbonate. Lapraik obtained the crystals by drying the aqueous solution over sulfuric acid, but the crystals are more easily obtained by precipitation in ethanol. 

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