DE. A. W. HOFMANN ON THE PHOSPHOEHS-BASES. 
605 
Theory, 
Experiment. 
1 equiv. of Phosphonium 
. . 121 
37-09 
1 equiv. of Platinum . . . 
. . 98-7 
30-26 
29-86 
3 equivs. of Chlorine ... 
. . 106-5 
32-65 
1 equiv. of Platinum-salt 
. . 326-2 
100-00 
Salts of Ethylene-hexmethyl-diphosphonium. 
Bibromide . — This salt is formed when dibromide of ethylene is treated with an excess 
of trimethylphosphine. The reaction is rapidly accomplished at the temperature of 
boiling water. The salt resembles the dibromide of the ethyl-series in its properties. 
It is extremely soluble, and was only once obtained in well-defined crystals, which were 
analysed and determined. Many efforts were made to produce these well-formed crystals 
a second time, but without success. 
0‘2940 grm. of dibromide gave 0’3246 grm. of bromide of silver, corresponding to the 
formula 
Cg H22 P2 Br 2 = 
Br2, 
(CH3)3Pj 
as seen by the following comparison of the theoretical and experimental percentages 
bromine : — 
Theory. 
Experiment. 
1 equiv. of Diphosphonium 
. . 180 
52-94 
2 equivs. of Bromine . . . 
. . 160 
47-06 
47-00 
1 equiv. of Dibromide . . 
. . 340 
100-00 
of 
The following are the details of Sella’s crystallographical determination : — 
“ System monoclinic ; — 
100,101 = 17^45'; 1 0 1, 0 0 1 = 20° 4'; 0 1 0, 1 1 1 = 57° 47'. 
Forms observed : — Pig- 
001, 110, 101 (Fig. 64). 
Forms observed : — 
MDCCCLX. 
Angles, 
Calculated. 
Observed. 
110, 0 01 = 
58 22 
58 22 
001, TOl = 
80 52 
80 50 
110, TlO = 
83 13 
83 12 
110, loi = 
x: — 
108 35 
108 33 
J:c = 1-1255: 
1:0-5445; 
y = 37° 49'. 
OP, 00 P, P 00. 
3 X 
