| 1 | 666-03-5 | Sulfuric acid 2-aminoethyl=sodium salt | | | | |
| 2 | 666-08-0 | 2-azaspiro[3.5]nonane | C8H15N | 125.214 | | |
| 3 | 666-14-8 | glycolate | C2H3O3- | 75.04 | | |
| 4 | 666-15-9 | methylsulfinyloxymethane | C2H6O2S | 94.13 | | |
| 5 | 666-16-0 | Cyclobutane, fluoro- | C4H7F | 74.0967832 | | |
| 6 | 666-19-3 | Ethene, 1,2-dibromo-1-chloro-2-fluoro- | C2Br2ClF | 238.28 | | |
| 7 | 666-21-7 | Butane, 2,3-difluoro- | C4H8F2 | 94.1031264 | | |
| 8 | 666-22-8 | Silane, fluoromethyl(1-methylethyl)- | C4H11FSi | 106.2140432 | | |
| 9 | 666-23-9 | tetrafluorophenylphosphorane | C6H5F4P | 184.07 | | |
| 10 | 666-25-1 | Propane, 1,2,3-tribromo-1,1-difluoro- | C3H3Br3F2 | 316.76 | | |
| 11 | 666-26-2 | 1-Butene, 4,4,4-trifluoro-3-methyl- | C5H7F3 | 124.1 | | |
| 12 | 666-27-3 | HCFC-241 | C3H3Cl4F | 199.87 | | |
| 13 | 666-32-0 | 1-BROMO-2,3,3,3-TETRAFLUOROPROPENE | C3HBrF4 | 192.94 | | |
| 14 | 666-33-1 | 3-Buten-2-ol, 1,1,1-trifluoro- | C4H5F3O | 126.08 | | |
| 15 | 666-40-0 | 1,1,3,3-Tetrafluoro-2,3-Dibromopropene | C3Br2F4 | 271.83 | | |
| 16 | 666-44-4 | 1-Propene, 2-chloro-1,1,3,3-tetrafluoro-3-iodo- | C3ClF4I | 274.3831828 | | |
| 17 | 666-52-4 | Acetone-d6 | C3D6O | 64.12 | −93.8°C(lit.) | Soluble in water. |
| 18 | 666-62-6 | Diphosphine, 1,1-dimethyl-2,2-bis(trifluoromethyl)- | C4H6F6P2 | 230.0283812 | | |
| 19 | 666-84-2 | [1R-(1alpha,4abeta,4balpha,10aalpha)]-1,2,3,4,4a,4b,5,6,10,10a-decahydro-7-isopropyl-1,4a-dimethylphenanthren-1-methanol | C20H32O | 288.47 | | |
| 20 | 666-93-3 | METHYL 3,3,3-TRIFLUORO-2-IODOPROPIONATE | C4H4F3IO2 | 267.97 | | |
| 21 | 666-97-7 | 1H-Pyrazole-1-sulfonyl fluoride | C3H3FN2O2S | 150.13 | | |
| 22 | 666-99-9 | AGARIC ACID | C22H40O7 | 416.55 | 142° (dec) | |