Similar Chemical Section
Applicability: Cranium, Synapse (core versions 0315+)

The Similar Chemical section contains one field – the Similar Chemical field.

(1,3,5-trimethylbenzene is similar in structure to toluene)

This field stores the name of a chemical having a molecular structure similar to that of the current chemical. Some estimation techniques use the properties of the similar chemical as a starting point for the property estimates of the current chemical. The values are modified depending upon the differences in molecular structures. For example, if the current chemical was propanol we might specify ethanol as a similar chemical. To estimate propanol’s boiling point, some estimation techniques would first find ethanol's boiling point and then adjust the value to account for propanol's extra methylene group.

Several estimation techniques use a similar hydrocarbon as the basis for initial property values. For example, to estimate the properties of 1-hexanol, such an estimation technique would start with the physical property value for n-hexane and then modify this value to adjust for the differences between the two structures.

Editing a Datum Value

Clicking the left mouse button on the section's edit control activates the Similar Chemical edit dialog. The dialog enables you to enter the name of a similar chemical, a reference, and comments.

The Similar Chemical edit dialog has many of the same controls as the Text-Reference dialog. Documentation on the Text-Reference dialog can be found here.

Find Button: pressing the dialog's Find button activates the Select Chemical dialog. This dialog lists all the chemicals in the current document. The dialog enables you to list chemicals by name or synonym. See the documentation on the All Entities Dialog for details.
Dialog Commands Menu

The commands menus for text entry controls, e.g., the name control, the reference control and the comments control, have commands for copying, pasting, inserting symbols, and changing case. The commands menu is displayed by clicking the right mouse button on a text entry control.

Documentation on each of the menu commands can be found here. See also documentation for the Symbol Dialog and Changing Case.

Datum Commands Menu

Clicking the right mouse button within a field's datum control activates the field's datum commands menu.

Documentation on each of the menu commands can be found here.

Example: Specify a similar structure for 1-hexanol
  1. Open a knowledge base document. (Open a "working" document or create a copy of a document (see here) if you are just experimenting with this functionality.)
  2. Change to the Chemicals chapter and navigate to 1-hexanol. (See Navigation for navigation documentation.)
  3. Scroll to the Similar Chemical Section and click the left mouse button on the section's edit field. The application activates the Similar Chemical dialog.
  4. Enter the name "n-Hexane" into the Similar Chemical edit control or press the Find button. Pressing the Find button activates the Choose Similar Chemical dialog.
  5. Select a chemical from the Entities list and press the OK button.
  6. Optionally, enter a value for the datum's reference and any relevant comments. For example, pressing the Date button will enter the current date and time into the edit control. Pressing the Phrase button will enter the currently stored phrase into the edit control. Pressing the Set button enables you to change this stored phrase. (See the Phrase Dialog documentation for more details.)
  7. Finally press the Similar Chemical dialog's OK button Save button to store the value into the current document and display it in the Similar Chemical field.
Related Documentation
Topic Description
Getting Started using Synapse provides a quick tour of Synapse's capabilities including examples of chemical product design.
Getting Started using Cranium provides a quick tour of Cranium's capabilities including a discussion of structure editing.