| 1 | 289-02-1 | 1,4,2-Dioxazole | | | | |
| 2 | 289-04-3 | 1,3,4-Oxathiazole | C2H3NOS | 89.12 | | |
| 3 | 289-06-5 | 1,3,4-Thiadiazole | C2H2N2S | 86.12 | 42.5°C | |
| 4 | 289-11-2 | 1,4,2-Oxathiazole | | | | |
| 5 | 289-13-4 | 1,3,4-Selenadiazole | C2H2N2Se | 133.01 | | |
| 6 | 289-14-5 | 1,2,4-trioxolane | C2H4O3 | 76.05 | | |
| 7 | 289-16-7 | 1,2,4-Trithiolane | C2H4S3 | 124.25 | | |
| 8 | 289-19-0 | 1H-Pentazole | HN5 | 71.04 | | |
| 9 | 289-22-5 | Cyclopentasilane Discontinued (Explosive) | H10Si5 | 150.51 | | |
| 10 | 289-24-7 | Aluminum, 1,3-pentadien-1-yl-5-ylidene- (9CI) | C5H5Al | 92.0747 | | |
| 11 | 289-31-6 | 1-Arsabenzene | | | | |
| 12 | 289-52-1 | Bismin | C5H7Bi | 276.08946 | | |
| 13 | 289-56-5 | 1,3,5-Trioxa-2,4,6-triboracyclohexane | B3H3O3 | 83.46 | | |
| 14 | 289-59-8 | Borthiin | C4H5BS | 95.9585 | | |
| 15 | 289-62-3 | Germin, hexahydro- | C5H12Ge | 144.79 | | |
| 16 | 289-65-6 | 4H-pyran | C5H6O | 82.1 | | |
| 17 | 289-66-7 | 2H-Pyran | | | | |
| 18 | 289-67-8 | Pyrylium | C5H5O | | | |
| 19 | 289-68-9 | Phosphabenzene | C5H5P | 96.07 | | |
| 20 | 289-70-3 | 4H-Thiopyran | C5H6S | 98.16614 | | |
| 21 | 289-72-5 | 2H-Thiopyran | C5H6S | 98.17 | | |
| 22 | 289-73-6 | 1λ4-Thiopyran | C5H6S | 98.16 | | |
| 23 | 289-74-7 | Hydroxyecdysone | C5H5S+ | 97.15 | | |
| 24 | 289-75-8 | Antimonin | | | | |
| 25 | 289-77-0 | Silabenzene | C5H6Si | 94.18664 | | |
| 26 | 289-78-1 | stannin | C5H5Sn | | | |
| 27 | 289-80-5 | Pyridazine | C4H4N2 | 80.09 | -8 °C (lit.) | MISCIBLE |
| 28 | 289-81-6 | 4H-1,2-Oxazine | | | | |
| 29 | 289-82-7 | 2H-1,2-Oxazine | | | | |
| 30 | 289-83-8 | 6H-1,2-Oxazine | | | | |
| 31 | 289-86-1 | 1,2-Thiazin-1-ium (8CI,9CI) | C4H4NS | 98.1463 | | |
| 32 | 289-87-2 | 1,2-Dioxin | C4H4O2 | 84.07 | | |
| 33 | 289-89-4 | 1,2-Oxathiin | | | | |
| 34 | 289-93-0 | 1,2-Dithiin | C4H4S2 | 116.2 | | |
| 35 | 289-95-2 | Pyrimidine | C4H4N2 | 80.09 | 20-22℃ | soluble |
| 36 | 289-96-3 | 1,2,3-Triazine | C3H3N3 | 81.07602 | 66 °C | |
| 37 | 289-98-5 | 2H-1,2,6-Oxadiazine | C3H4N2O | | | |