Chemical Features of MarvinSketch

Table of Contents

Valence Check

MarvinSketch does not automatically correct valence errors. Instead, they are highlighted by a red underline and you may make the appropriate corrections. This option can be turned on or off using the Edit > Preferences box.

Charges

In MarvinSketch, the charge of an atom is initially set to be neutral. As bonds are added or removed, MarvinSketch adjusts the number of implicit hydrogens to let the charge remain neutral. You may change the charge of any atom using the Atom Pop-up Menu. The number of implicit hydrogens will be adjusted, if possible, to accommodate the new charge. MarvinSketch will then perform a valence check and highlight the atom if an error is found.

Reactions

MarvinSketch allows you to draw reactions in your molecule by placing a reaction arrow. You can place the reaction arrow in any position, pointing in any direction. The structures before the arrow will be considered Reactants, structures along the arrow Agents, and structures after the arrow as Products.

Mapping

MarvinSketch allows you to set a map label on any atom in the molecule. Map labels are useful because they remain constant, unlike atom indexes, which can change as the molecule is altered. Atom mapping can be very useful when drawing reactions. It allows you to specify that specific reactant atoms will become specific product atoms. You can assign the same free map number to both of these atoms by pressing the Reaction Button on the toolbar, then drawing the arrow from the first atom to the second one. You can also select a Map for an atom from the Atom Pop-up Menu, or else you can use the Edit Pop-up Menu to automatically assign map numbers to selected atoms. You can also use the shortcuts M1, M2, ... to assign map labels, M0 to remove map labels, M= or M+ to assign unique map numbers.

Isotopes

MarvinSketch allows you to change an atom into one of its isotopes using the Atom Pop-up Menu.
There is the possibility to extend the isotope list with custom items. Technical details.

E/Z Feature

By choosing View > Stereo > E/Z Labels , you can toggle the display of absolute double bond stereoconfiguration labels. Bonds known to have an (E) or (Z) configuration will be marked as such.

S-groups

MarvinSketch has a rich collection of features related to abbreviated groups.

Predefined Abbreviated Groups

A number of predefined S-groups are available in MarvinSketch. The complete set is listed under the Groups menu. These groups are also available as shortcuts.
Their usage is described in the Basic MarvinSketch page.
The rotation of the molecule might change the groups' writing order, thus retaining the chemically correct connectivity. Read a detailed description of this feature.

User-Defined Abbreviated Groups

You can easily create new groups that you often use. Select the structure and give it a name (Structure > Groups > Create Group) and if needed, define an attachment point. Details.

S-groups as My Templates

User-defined groups are, by default, session-only. To retain a group for future use, add it to My Templates. This will also make the group available in the Groups menu or as a shortcut.

Link Nodes

Link nodes enable specifying query stuctures contaning rings or chains of variable size. In the following example, the number of carbons can be between 1 and 7:

Working with Groups

Group manipulation functions are available through the Structure > Group submenu and by right-clicking on an existing group.
Choosing Contract from the context menu or Structure > Group > Contract Group from the main menu contracts one group to its abbreviation if there is one group selected, otherwise contracts all groups in the molecule.
Choosing Expand Group from the context menu or Structure > Group > Expand Group from the main menu displays the full structure instead of a contracted group if there is one group selected, otherwise expands all groups in the molecule.
Selecting Ungroup will remove all abbreviated groups from the molecule. The structures will remain, but will no longer be associated with their abbreviations. You will be unable to Expand/Contract these structures.
To add or remove an Attachment Point, right-click on an atom within the group and select the Group > Attachment Point checkbox.

Working with Radicals

MarvinSketch allows you to specify that an atom in the molecule is a radical. This functionality is available via the Atom Pop-up Menu.
To change an atom into a radical, right-click on it to access the Atom Pop-up Menu. Select the type of radical from the Radicals submenu. A radical symbol will appear next to the atom and a valence check will be run with errors highlighted.

Query Guide

The JChem query guide provides more detailed information on how to use query structures created in MarvinSketch with JChem's query functionality. The following are some of the query building features available in MarvinSketch.

R-groups

MarvinSketch allows you to specify R-groups within your molecule. These R-groups can be very useful in R-group queries. An R-group is a variable representing a user-defined list of structures. Using R-groups in a query structure can allow you to quickly search for a wide range of substructure hits using only a single query.
You can set or change the R-group label of a molecule node from the Atom Pop-up Menu or by typing the corresponding R-group label on the keyboard.
To define the set of structures that are represented by an R-group label, select the structures you wish to include. Then, select the corresponding label from the Periodic Table or use one of type the R-group label on the keyboard. Set additional Occurence, RestH and If-then conditions for the query in the R-logic dialog available from the Edit/Attributes menu.

Atom Lists

MarvinSketch allows you to add Atom List query atoms to your molecule. An Atom List is a user-defined list of elements included in a query structure, any of which will produce a hit if found in the target.

You can add Atom Lists to your molecule through the Periodic Table. To add an Atom List to the molecule, select the Atom List button, then select the elements you wish to include in the list. Move the mouse into the canvas and click to add a query atom representing this atom list.

Not Lists

A Not List is a query atom that allows you to define a list of elements that should not be included in the target structure. If an atom within the query structure is set as a Not List, then the atom in the same position within the target structure can be any atom that is not on the list to produce a hit.
To add a Not List to the molecule, select the Not List button in the Periodic Table, then select the elements you wish to include in the list. Move the mouse into the canvas and click to add a query atom representing this not list.

Generic Atoms

Generic atoms can be added to include a wide range of elements in a query structure. Currently, MarvinSketch supports two types of generic atoms: Any and Hetero
If an atom within the query structure is designated as "Any", any atom at this position in the target structure will produce a hit.
If an atom within the query structure is designated as "Q", then the atom at this position can be any heteroatom (i.e. any atom except hydrogen or carbon) and it will produce a hit.
To add a generic atom to the molecule, select one of the generic atom types from the Periodic Table and place it on the canvas with the mouse.

Atom Properties

You can define the chemical neighborhood for an atom within a query structure. MarvinSketch allows you to set properties, such as hydrogen count, valence count, ring size, and aromaticity, which must be matched by the corresponding atom in the target structure to produce a hit.
To set or change atom properties, select an atom property button from the Periodic Table. To apply this property, click on the desired atom.

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