| 1 | 288-01-7 | 1H-phosphole | C4H5P | 84.056261 | | |
| 2 | 288-05-1 | SELENOPHENE | C4H4Se | 131.03 | −30°C(lit.) | |
| 3 | 288-06-2 | 1-Silacyclopentane | C4H10Si | 86.21 | | |
| 4 | 288-07-3 | 1H-Stannole | C4H6Sn | 172.8 | | |
| 5 | 288-08-4 | Telluracyclopentadiene | C4H4Te | 179.67456 | | |
| 6 | 288-09-5 | Zirconium, 1,3-butadiene-1,4-diyldihydro-, (T-4)- (9CI) | C4H4Zr | 143.3 | | |
| 7 | 288-12-0 | 3H-Pyrazole | C3H4N2 | 68.07726 | | |
| 8 | 288-13-1 | Pyrazole | C3H4N2 | 68.08 | 67-70 °C (lit.) | SOLUBLE |
| 9 | 288-14-2 | Isoxazole | C3H3NO | 69.06 | -67.1°C | |
| 10 | 288-16-4 | Isothiazole | C3H3NS | 85.13 | 176 °C (decomp)(Solv: water (7732-18-5)) | |
| 11 | 288-20-0 | 1,2-Oxaphosphole | C3H3OP | 86.03 | | |
| 12 | 288-22-2 | 3H-1,2-Oxathiole | | | | |
| 13 | 288-26-6 | 3H-1,2-Dithiole | C3H4S2 | 104.19 | | |
| 14 | 288-27-7 | 1,2-Dithiol-1-ium | C3H3S2+ | 103.18 | | |
| 15 | 288-30-2 | 4H-imidazole | C3H4N2 | 68.08 | | |
| 16 | 288-31-3 | 2H-Imidazole | C3H4N2 | 68.08 | | |
| 17 | 288-32-4 | Imidazole | C3H4N2 | 68.08 | 88-91°C(lit.) | 633 g/L (20 ºC) |
| 18 | 288-33-5 | Mercury, [ethanediiminato(2-)-κN,κN']- (9CI) | C2H2HgN2 | 254.64 | | |
| 19 | 288-34-6 | 4H-1,2,3-Triazole | C2H3N3 | 69.07 | >300 °C (decomp) | |
| 20 | 288-35-7 | 2H-1,2,3-Triazole | C2H3N3 | 69.0653 | | |
| 21 | 288-36-8 | 1,2,3-triazole | C2H3N3 | 69.07 | 23-25°C(lit.) | soluble |
| 22 | 288-37-9 | 1,2,5-oxadiazole | C2H2N2O | | | |
| 23 | 288-38-0 | 1H-1,3,2-Diazaphosphole | | | | |
| 24 | 288-39-1 | 1,2,5-Thiadiazoles | C2H2N2S | 86.12 | -50.1°C | |
| 25 | 288-40-4 | 1,2,5-Selenadiazole | | | | |
| 26 | 288-41-5 | 1,3-Diaza-2-silacyclopentane | C2H8N2Si | 88.18 | | |
| 27 | 288-42-6 | oxazole | C3H3NO | 69.06 | −87-−84°C(lit.) | Miscible with alcohol and ether. Slightly miscible with water. |
| 28 | 288-43-7 | 1,2,3-Oxadiazole | | | | |
| 29 | 288-46-0 | 3H-1,2,3-Oxathiazole | | | | |
| 30 | 288-47-1 | Thiazole | C3H3NS | 85.13 | -33°C | slightly soluble |
| 31 | 288-48-2 | thiadiazole | C2H2N2S | 86.12 | | |
| 32 | 288-49-3 | 5H-1,2,5-Oxathiazole | C2H3NOS | | | |
| 33 | 288-52-8 | Selenazole | C3H3NSe | 132.02 | | |
| 34 | 288-53-9 | 1,3-Dioxole | C3H4O2 | 72.06 | | |
| 35 | 288-55-1 | Copper, [1,2-ethenediolato(2-)-κO,κO']- (9CI) | C2H2CuO2 | 121.58 | | |
| 36 | 288-59-5 | 1,3,2-Dioxaphosphole(8CI,9CI) | C2H3O2P | 90.017781 | | |
| 37 | 288-64-2 | 1,3-Dioxa-2-silacyclopentane | C2H6O2Si | 90.15 | | |
| 38 | 288-66-4 | Zinc, [1,2-ethenediolato(2-)-κO,κO']- (9CI) | C2H2O2Zn | 123.42 | | |
| 39 | 288-67-5 | 1,3-Oxathiole | C3H4OS | | | |
| 40 | 288-68-6 | 1,3,2-Oxathiazole | | | | |
| 41 | 288-70-0 | 1,2,3-Oxadithiole | | | | |
| 42 | 288-74-4 | 1,3-Dithiole | C3H4S2 | 104.19 | | |
| 43 | 288-75-5 | 1,3-Dithiol-1-ium | C3H3S2+ | 103.18 | | |
| 44 | 288-76-6 | Mercury, [1,2-ethenedithiolato(2-)-κS,κS']- (9CI) | C2H2HgS2 | 290.75 | | |
| 45 | 288-77-7 | 1,2,5-Oxadithiole | | | | |
| 46 | 288-86-8 | 1-Aza-2,5-disilacyclopentane | C2H9NSi2 | 103.27056 | | |
| 47 | 288-87-9 | 1-Oxa-2,5-disilacyclopentane | C2H8OSi2 | 104.25532 | | |
| 48 | 288-88-0 | 1,2,4-1H-Triazole | C2H3N3 | 69.07 | 119-121 °C (lit.) | 1250 g/L (20 ºC) |
| 49 | 288-90-4 | 1,2,4-oxadiazole | C2H2N2O | 70.05 | | |
| 50 | 288-91-5 | 1H-1,4,2-Diazaphosphole | | | | |
| 51 | 288-92-6 | 1,2,4-thiadiazole | C2H2N2S | 86.12 | -33°C | |
| 52 | 288-93-7 | 1,2,4-Selenadiazole (8CI,9CI) | C2H2N2Se | 133.01 | | |
| 53 | 288-94-8 | 1H-Tetrazole | CH2N4 | 70.05 | 156-158°C | Soluble |
| 54 | 288-98-2 | 3H-1,2,4-Dioxazole | | | | |
| 55 | 288-99-3 | oxdiazole | C2H2N2O | 70.05 | | |