Draw structures that snap to real bond angles, scale reactions, plan distillations and read spectra. In your browser, with the chemistry checked while you work.
Draw and view structures
Spectroscopy
Bench calculations
Distillation and physical data
Medicinal chemistry
Covalent places every new bond at a real bond angle: 120° zigzags, linear triple bonds, rings fused on the side you point at. Valence, charges and stereochemistry are checked while you draw, so an impossible structure never gets drawn.
Open CovalentOpen JCAMP-DX, SPC or CSV files from any instrument, pick peaks and integrate in Signum, predict 1H and 13C shifts from a structure, and convert everything to CSV or Excel without uploading a byte.
Open SignumScale a reaction from the amount of one reagent, find the limiting reagent, work out a buffer, or see which fractions a distillation will give at your pressure, with boiling points from real Antoine data.
Reaction scaleHow reactions are written down and searched backwards, from RXN files, reaction SMILES and SMIRKS to the USPTO and ORD datasets and open retrosynthesis tools.
How NMR, IR, UV-Vis and mass spectra are stored on disk, from JCAMP-DX to mzML, nmrML and NMReDATA, and which formats keep the structure with the spectrum.
How molecules are stored on disk, from the PDB format and MDL molfiles to CIF, CML, CDXML and CXSMILES, with ethanol as the running example.
Free, fast, and built for the people who do the chemistry. Press CtrlK anywhere to search.