205 



which have already been investigated and described in a former 

 paper ^). They are triclinic-pinacoidal, and coniplelelv isoniorphoiis 

 with the corresponding raceniic r/iO(lhu/i-sa\t, so that the direct 

 isomorphons snbstitntion of the metals Rho and Ir, also in their 

 complex salts, has been hereby dednitely proved. As we shall see, 

 this proof has now also been given in the case of the opticnlh/- 

 active components of snch complex salts. 



§. 3. Fission of the vacemic Potassium- Iridium- Oxalate (-{-4V,//,^>) 

 into its opti('a/li/-active components. 



27,5 Grams of pnre stn/chnuie-nitrate are dissolved in 1300 ccm. 

 boiling water; then a solntion of 15,5 grams of the racemic salt 

 in 250 CCS water of 60° C. is rapidly ponred into the boiling 

 solntion nnder perpetnal stirring. The flask with the golden yellow 

 licpiid is allowed to cool slowly for twelve hours to room-tempera- 

 tiire. The deposited, highly yellowish coloured, felty-like crystals 

 are sharply sucked off at the water-pump, washed with some 

 strong alcohol, afterwaids with some ligroine, and dried at I'oom- 

 temperature in an air-cnrient. The mother-liquid is evajiorated 

 on the waterbath to about */, of its original volume; on cooling 

 highly yellow, needle-shaped crystals are again deposited, which are 

 treated in the same way. While the first fraction, however, represents 

 the stri/cJmine-sa\t of the (/e'.r^rögy rato ry component, — the hievo- 

 gyrate antipode was immediately obtained from the second precipi- 

 tate. On further evaporation of the filtrate, some paler coloured 

 fractions are consecutively obtained, all of which give the laevo- 

 gyratory potassinni-Q&\\. The sixth and the seventh fraction finally con- 

 sisted of pure strychnine, accompanied by some of its nitrate, while 

 in the last fractions crystals of the free, racemic potassium-sali 

 together with some of the laevo-salt, and also some potassium- 

 nitrate, appeared. The rotation of this last fraction as a whole, after 

 removing the potassium-nitrate, was negative, amounting only to 

 about 7? of the rotation of the pure laevogyrate salt, so that a 

 considerable amount of racemic salt is evidently admixed. Probably 

 a partial hydrolysis during the repeated evapoi-ations has taken 

 place, so that the free potassiumsalt accumulates in the last fractions. 



The strychnine-saU of the </(^.i'^?'()gyratory component has the formula: 

 |/r(6\Oj,|5(C,i//2,/V,(>J, + ?>{HJ)', it appears as pale yellow, very 

 fine needles. For a series of wave-lengths the rotation of this strongly 

 active salt was determined; the solution used contained 0,4763 

 grams of the hydrated salt in 100 ccs. of the liquid. 



') F. M. Jaeger, Proceed, R. Acad. Amsterdam. 20, 278, (1917). 



