| 556 / | HD | ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES |
| * | DD | ORGANIC COMPOUNDS (Class 532, Subclass 1) {3} |
| 170 | DF | .~ ALUMINUM CONTAINING {11} |
| 181 | DF | .~.~ Chalcogen bonded directly to aluminum {1} |
| 182 | DF | .~.~.~ Plural chalcogens bonded directly to the same aluminum {2} |
| 185 | | .~.~.~.~ Preparing by oxidation |