Microdetermination of Oxygen in Phosphorus-containing Compounds

The modification of the standard procedure involves the use of a disposable sample boat. A piece of copper foil approximately 1 X i in. in size is shaped manually into boat form. It is flamed in a Bunsen burner and dipped into methanol. After this cleaning operation, the boat is placed in a glass tube and heated briefly with a Bunsen flame while being swept with a stream of hydrogen (caution ) it is then ready for use in the procedure described by Oliver. Some typical results are given in Table I. Anal. Calcd. for CarHaoClOPzRh O, 2.32. Found 0, 2.30, 2.34. By checkers Calcd C, 64.32 H, 4.38 mol. wt., 691. Found C, 64.49 H, 4.61 mol. wt., 688 4. Calcd. for Cj7H3oC10As2Rh O, 2.05. Found O, 1.95, 2.10. By checkers Calcd C, 57.06 H, 3.88 , mol. wt., 778. Found C, 57.65 H, 4.43 mol. wt., 790 13. 

1 The weight of the analytical sample is adjusted to correspond to a final titration of the liberated iodine with about 3 ml. of 0.02 N sodium thiosulfate. The errors on all values are 0.3. 

Chlorocarbonylbis(triphenylphosphine)rhodium and chlorocarbonylbis(triphenylarsine)rhodium form bright yellow crystalline solids which are readily soluble in chloroform and dichloromethane, moderately soluble in benzene and carbon tetrachloride, and sparingly soluble in ether and aliphatic hydrocarbons. The phosphine complex (m.p. 195 to 197°) and the arsine complex (m.p. 242 to 244°) are reported to have carbonyl stretching frequencies (using KBr disks) at 1960 and 1963 cm., respectively.  

Both compounds react with chlorine or iodine by adding a molecule of the halogen to give [(C6Hi)3M]2Rh(CO)X2Cl (X = Cl or I).  

Oliver The Direct Micro-determination of Oxygen, in Compre- 

SODIUM H XACHLORORHODATE(m) 2-HYDRATE AND POTASSIUM HEXACHLORORHODATE(m) 1-HYDRATE 

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