| 556 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {3} |
| 1 | DF | .~ HEAVY METAL CONTAINING (e.g., Ga, In or T1, etc.) {19} |
| 13 | DF | .~.~ Phosphorus containing {6} |
| 19 | DF | .~.~.~ Carbon bonded directly to the phosphorus {1} |
| 20 | DF | .~.~.~.~ Plural carbons bonded directly to the phosphorus {1} |
| 21 | DF | .~.~.~.~.~ Exactly three carbons bonded directly to the phosphorus (e.g., triphenylphosphines, etc.) {2} |
| 22 | ![]() | .~.~.~.~.~.~ And carbon bonded directly to the heavy metal |