Structure to Name History of Changes

Structure to Name 16.02.22


  • When using the API to conver a structure to common name (format option "name:common") or to CAS registry number (format option "name:cas#"), an exception of class chemaxon.naming.s2n.NoKnownNameException is now thrown when no common name or CAS registry number is known for the structure. This is intended to make it easier for programs to distinguish those situations from failures.

Structure to Name 15.11.16

Bug fixes

  • Saturated rings inside fused ring systems are now correctly named based on the insaturated ring names (for instance pyrazine instead of piperazine) together with hydro prefixes.

Structure to Name 15.10.26

Bug fixes

  • In structures with sulfonamides (and similar groups) connected to a cyclic parent and N-substituted with some complex acyclic components, the wrong parent was selected, leading to incorrect IUPAC names.

Structure to Name 15.07.27


  • Correct IUPAC names are now generated for simple inorganic molecules of two identical atoms such as dinitrogen and dichlorine.

Structure to Name 15.07.06

New features

  • IUPAC Names are now generated for ring assemblies of size 2, such as biphenyl, bifuran, bicyclohexane, ...

Structure to Name 15.06.29


  • The group carbodithioate is now recognized.

Bug fixes

  • Some multiplied substituents were missing surrounding parentheses.

Structure to Name 15.06.08


  • The group sulfinimidoyl is now recognized.

Structure to Name 15.05.18

Bug fixes

  • Substituted benzyl was used in generated names, while this is not allowed by the IUPAC rules. These structures now get names based on substituted phenyl connected to a methyl parent, following the IUPAC rules.

Structure to Name 15.04.20

Bug fixes

  • Some ring substituents were missing locants for their own substituents.

Structure to Name 15.04.06


  • When using the "ascii" option, non-standard valences will be indicated using "lambda..." instead of "$l^{...}" so that the name is easier to read.

Structure to Name 15.03.02

New features

  • Reaction molecules are now named by separating the reactents, reagents and products. For instance, molconvert name:t -s '[C].O=O>>O=C=O' returns "carbon + dioxygen ? carbon dioxide".

Structure to Name 15.02.23

Bug fixes

  • The "carbonylimino" group was wrongly named as "amido".

Structure to Name 14.12.15


  • IUPAC compliant names are now generated for racemic mixtures, such as rac-(2R,3R)-3-bromobutan-2-ol.

Bug fixes

  • Name generation could fail on instances of the RgMolecule class when assertion checking is enabled.

Structure to Name 14.12.08


  • Following the new 2013 IUPAC rules, use locants N,N",N' for guanidine instead of the previously used locants 1,2,3.

  • Adopt the new IUPAC 2013 rules for parentheses. This leads to slightly more parentheses in some cases, where this is useful to avoid any ambiguity.

Bug fixes

  • Structures with a cis/trans double bond resulting of the substitution of a parent functional group were named with an unnecessary and invalid "ene" suffix.

  • Structures with a radical on a chalcogen atom (O, S, ...) connect to a cyclic component were named incorrectly (ignoring the radical and substituents)

  • Some common names failed to be recognized depending on irrelevant factors, such as the atom order in the input structure.

  • Some structures with multiple identical functional groups were sometimes assigned different names depending on irrelevant factors, such as the atom order in the input structure.

July 28th, 2014: Structure to Name 14.7.28

New Features and Improvements

  • IUPAC names are generated for halonium ions, such as bromanium, chloranium, ...

July 7th, 2014: Structure to Name 14.7.7

New Features and Improvements

  • A novel nomenclature for enhanced stereochemistry has been introduced to name structures with multiple independent OR groups.

  • IUPAC names are now generated for phosphorothioic acid, phosphonothioic acid, and their derivatives, including their esters.

  • Significant improvements in parent selection, resulting in a stricter adherence to IUPAC rules, especially for amines and imines.

  • The name succinamide is now used in traditional mode.

  • Use unicode superscript representation for interior fusion atoms, for instance in 3a¹H-phenalene.

Bug Fixes

  • Wrong locants (typically N instead of N') were generated for some structures with a substituted multiplied suffix.

  • Name generation was failing on some structures with isotopes.

  • For structures with isotopes, generated names used to contain non-ASCII Unicode characters even when the ASCII option was used.

  • A valid but suboptimal numbering was chosen in some cases, for instance (3S,4R)-2,5-diamino-3,4-dimethylhexanedioic acid instead of (3R,4S)-2,5-diamino-3,4-dimethylhexanedioic acid.

  • Fixed stack overflow when generating a name in the rare case of a *-O=N-* configuration.

  • Structures containing an ester and a separate fragment were named as if they were a single fragment. They are now named separately using the ';' fragment name separator.