C472 Exercise 4 Spring 2003

STN Express Structure Searches

Due: 3/26/03
Updated: 4 March 2003

STN Express searching
Remember to capture your entire session online so that you can get a printout after logging off. Name your capture file 472ex4zz, replacing the final zz's with your initials. (Once logged on, verify that the Capture Session option is checked under Results.)

1. Conduct exact, family, and substructure searches in the LREG file for this substance and print out one answer for each in the default view.

2. Substructure search. No further substitution is allowed on either ring. Print out one answer in the default view.

3. Substructure search. The C attached to the solid line can be a ring or chain node, and the bond that is dashed is either a ring or chain bond. Find the appropriate substances, and print out the first answer in the default format.

4. Find references on substances with this structure, where R=any halogen, Me, or N. Print out the first two answers in the default format.

5. Find the Registry Number for this compound. Print out the first answer in the default format.

6. Using the STN Express structure drawing program, build the structure for the image below and save it.

Perform the following searches.

  1. Perform an exact search. How many hits did you get?
  2. Print out all answers in the default (IDE) format.
  3. Perform a family search. How many hits did you get?
  4. Using the FIDE format, print out ONLY one answer from the family search. Notice the additional types of information that you get about the compound by using the full structure identification format.
  5. Cross over into the LCA file using the FILE LCA command.
  6. Search the L# of your exact search (DISPLAY HISTORY may help) and print out the first answer in the ALL format. Note that Registry Numbers are used in the indexing of the answer. Which Registry Number resulted in the retrieval of this answer?

7. Find all the substances with the requirements listed below. Find the bibliographic references for these substances and print out the answers in the CBIB format.

8. Find the Registry number for this compound. Also find the bibliographic information and print the first answer in the CBIB format.

9. Find the Registry Numbers for this substance. Only the variation indicated is allowed. Find the bibiographic references also, and print the first answer in the CBIB format.

10. This structure can have chlorines or hydrogens at the indicated positions. Find all of these substances. How many substances did you find? How many bibliographic references are associated with this group of substances?

11. Has Edward M. Arnett written any articles about the substance shown below?

12. Find the Registry Number for this compound.

13. A group of chemists at Southern Illinois University is working on the compounds shown below. any substitution is acceptable on the ring portion of the structure. In the chain portion of the structure, methyl groups are required, as is the double bond. Substitution may occur on the other carbons. Ring fusion is not desired. How many compounds can you find? Find the references to these compounds in the LCA File and print the first in the CBIB format.

14. Find all compounds that have the basic structure shown below. Any substitution is allowed on the rings. However, ring fusion is not desired.

15. A chemist is interested in this basic substance. Most of the structure is well defined except for the six-membered ring which can be substituted at any position. Both of the rings are isolated. How many compounds in the LREG File have this basic structure?

16. This compound can be substituted at all positions, but at certain positions, the only substitutions that are desired are indicated below. In addition, both of the rings are to be isolated systems. How many compounds can you find? Find the bibliographic records in the LCA file and print out the BIB and HIT formats.

R1 = methyl, fluorine, or chlorine
R2 = methyl or ethyl

17. The compound below has much of the molecule well defined. Substitution is allowed everywhere on the structure. A variable position has been defined in the five-membered ring to be a carbon or sulfur. The entire ring system is to be isolated. How many compounds have this structure?

R = carbon or sulfur

18. The compound shown below can be substituted with anything at most positions. However, at three positions the substitution has been defined as indicated below. Both of the rings are to be isolated. How many compounds did you find? Also find the bibliographic references and print the first one in the CBIB HIT format.

X = any halogen
R1 = hydrogen, Cl, Me, or OMe
R2 = hydrogen, Cl, Me, Ome, or OEt

19. Draw the compound below and search it in the Learning Registry (LREG) file as a closed substructure search (CSS). You'll need to use the G-groups feature of STN Express in order to define the variable R groups below.

R1=O or S
R2=H, OH, OMe, CH3, or CO2H
X = any halogen
? = unspecified bond value

  1. Perform a closed substructure search. How many answers did you get?
  2. Print out the first and last answers in the IDE format.
  3. Cross over into the LCA file using the FILE LCA command. Under the Query option of STN Express, use the Predefined Search Strategy option and select the canmr item. Search the L# assigned to the NMR strategy. How many answers did you get?
  4. Now use the Discovery option to search the single term NMR as a subject. How many answers did you get?
  5. Do a DISPLAY COST FULL command and LOG Y
  6. Obtain a printout that shows all of your work in the STN Express session(s), write your name on it, and hand it in with the problem set.

20. Next, use SciFinder Scholar 2000 to do a substructure search for the compound in question 5.
How many compounds were found?
Print out only the first compound in your answer set in the default format.

Why are so many more compounds found in the SciFinder Scholar search than were located in the LREG family search?

21. What are the 4 structure search types allowed under the STN structure searching system? Define each of them and relate them to the two types of structure searches possible in SciFinder Scholar.

22. I downloaded the Alchemy (Concord) data associated with CAS RN 60505-89-7. Look at the raw data as downloaded from the Registry File by clicking here.

Take a look at the molecule by starting the program Alchemy 2000 on the Chemistry Library computer that has the Alchemy 2000 program (See: http://www.indiana.edu/~libchem/pcr.html The data are in the Alchemy Samples folder on that computer with filename: sci3d60606-89-7.mol.)

Choose the rotate option from the left-hand toolbar in Alchemy 2000 and rotate the molecule.

Choose the Display option from the top toolbar and look at some of the data given under Measurements.

In a few sentences, write your impressions of the Alchemy program for visualization of molecules. Comment on the added value that the Concord data gives to the Chemical Abstracts Registry File data.