REVIEWS NMR Slmulator Paul Schatz, COMPress, P.O. Box 102, Wentwonh, NH 03282
Hardware: IBM PC with CGA or EGA. Also available for Macintosh Components: Program disk, disk of sample spectra, and User's Manual Level and Subject: Organic chemistry cost: $95
such as the list of spectra or be bothered hy such as the installationprocedures. A COMPress technical service representative told me to photocopy the part I wanted the students to use. This, of course, violates copyright laws. T h e COMPress representative was reached with only two dialings and was extremely knowledgeable about the product. He was able to tell me about the Mac version as well. He informed me that the spectraare digitized rather than calculated. (More on this later.) He indicated he would pass on my complaints about the manual. The tutorial takes the student through the process of getting a spectrum out of the simulation hut does not truly provide areal,istie experience. Missing from this simulation is tuning. What is present is how to obtain a routine spectrum once the instrument is tuned. The first step is loading the sample (actually, reading a data file). The Program Disk has three example spectra and the Sample Data Disk contains 27 spectra files. Thirty spectra are acceptable far initial training hut are not enough for more general use. Three hundred digitized spectra are available for an additional $250. Data files are loaded by number hut the files can he renamed. Once the file is loaded, POWER, END OF SWEEP, SWEEP WIDTH, SWEEP TIME, and FILTER may he used in their standard positions or be modified. SWEEP TIME changes on the dial hut doesn't actually get altered; sweep time is about 50 seconds. SWEEP ZERO is then adjusted. Spectrum amplitude is fixed using AMPLITUDE SET. And the spectrum is
the student's focus is upon the NMR and none is needed for the computer. It's just like using a Mac. Help is readily available with an F2 push or a mouse pull down menu. The help screens include brief comments on the purpose of each dial and hutton end a small picture of that control. This sort of information is limited and t h e documentation stresses that this simulation is nota tutorial! It can provide practice but instruction and guidance are still required. The big advsntage is, of course, that the program costs onlv, a hundred dollars and the real instrumenr costs rena of thouiands. Also, uith a projection system or multiple units, man" more students can he trained simultaneously. The 5.5 in. X 8.5 in. manual has clear text and style hut contains many more misspellingsltypos than are acceptable. The figures are reduced screen dumns and are difficult t o read. Curiouslv.. t h e r i i s no nicture of an FM-3GOlTheRR pagesur.ntain ;he hardware requirements and i,ptiunu, inrtollation insrructmns, pnlgram description, stan-up procedure, tutorial, instructions for expanded scale spectra, offsets and print out, help screens, exiting, and six appendices. The 35page tutorial section called Obtaining an NMR Spectrum is well done and includes many of the important steps in the process. This should really be in a separate student manual though. The tutorial is stuck in the middle of the manualand the keyboard control sheet is in an appendix. No index is provided, so time is wasted searching through the manual. There are some things in the manual the students should not see ~
Review I Instrument simulators can be valuable teaching aids. The NMR Simulator by Paul Schatz is an impressive example of this type of program. The IBM version is contained on two disks; one holds the program and the other has additional spectra. The copy-proteeted program is easily made bootable hy running a small set-up program that copies your own PC DOS 2.0 or higher t o the disk. The program is loaded into RAM (needs 256K) and so a single-drive PC is adequate. I t can he easily loaded onto a hard drive, but the original diskmust be kept handy for use as a key. One archival program disk comes with the set. Once the program is booted the screen is filled with the control panel and recorder platen of a Varian EM-360 NMR. This choice of instruments is excellent since even many community colleges can afford it. The EM-360L is the version still available. The control panel can be operated from the keyhoard, but a mouse is much, much better. An NMR has many buttons and dials. As a heavy user of NMR, I found only a few minutes were necessary tolearn which keys control which functions. Students take much longer so a mouse is a h a t a necessity. The summary of key controls provided in an appendix was an essential aid and should have been provided as a separate card for those users without a mouse. With mouse use, all
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Cabgory Ease of Use: Subject Maner Content
Pedagogic Value: Student Rssctlon:
Revlewer
Revlewer
bod
Emellent Good Excellent
Oood
Excellent
--Reviewed In This Issue Revlewer
Computer Learning Packages Paul Schatz, NMR Simulator
J. H. Parish, Nucleic Acid Structure and Synthesis Frank and Craig Weinhold, Molecular Design Editor Fred D. Williams. Synthetic Adventure
Robert J . Newland Donna L. Ticknor Keith K. Parker Kirk McMichael Paul L. Weber
A296 A297 A298 A299 A300
J a m e s H. Brewster Vaughan Pultz
A300 A301 A302
Books Lionel Salem, of t h e Molecule Robert A. Alberty, Physical Chemistry, Seventh Edition Titles of Interest
A296
Journal
of Chemical Education
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recorded from low field t o high. The pen doesn't work in REVERSE mode. Integration is the next step. It was amusine to find that the BALANCE was as irritating toadjust un thissimulation as it is on the resl devrce. With the I'KN l', t hr A M PLITUDE id adjusted and then the integral is drawn a n the paper. The paper can he refreshed with two pushes of the backspace arrow or from a mouse menu. Print out is to any graphics dot matrix printer and is just a screen dump of the platen area. A plotter can he used though and full instructions for its use are included in the manual. I could not crash this program. The only thing I could do to it was make it produce errors concerning printing and this required having a bad printer connection. The error handling was not very informative since the message was Error #55 in line #3240. The oroeram .. resumed without difficultv. The spectra obtained are wry good.Thcy look real and, in fact, are real since each hns been digitired directly from an N\IR. Spmning side hands can be seen as well as ringing. The spectraare loaded a t whatever amplitude is currently set. Once the appropriate amplitude for a given spectrum is known, i t can he preset. Students should be assigned different unknowns to avoid this problem. A spectrum does come in a t a different SWEEP ZERO position each time and has t o be adjusted. Random noise is added to the spectrum during the run. The quality of the spectra can he seen best when expanded. The simulation includes all the expansion capahility possessed,by the EM-360. END OF SWEEP can he -4 up to 16 and SWEEP WIDTH can he set a t 1,2,5,10, or 20ppm. The quality of the output is reduced by changing the FILTER setting or the POWER but resolution is not destroyed if the values are altered a great deal. Limits have been placed on these controls. The biggest omission from this simulation is tuning capability. PHASE, Y, CURVATURE and RESOLUTION ADJUST do not function. This part of running a speetrum can he time consuming and difficult to learn. I t is apparently also difficult t o program. I used this program and its Mac equivalent t o train students in the use of a Varian T60 NMR. Training was made much simpler thereby and students had fewer difficulties when they ran spectra. Learning to tune the instrument still required much effort. The simulator was also used t o demonstrate NMR procedures to a group of students who would never use the actual instrument. They seemed t o have a better grasp of the topic than in the past. No before and after testing was done. Typical comments from bath groups included "wow," "neat," "Can I do it?" and so on. I can comfortably recommend this program t o instructors a t all levels who teach NMR. The manual needs work, but it is certainly usable for now. It would he nice to have the tuning aspect of NMR covered, but COMPress did not indicate such an upgrade was in the works. To get the full utility of this program it is necessary to have a mouseequipped IBM and to purchase the other data disks. The program does exactly what it says i t does, and i t does i t well. I give i t an overall rating of good plus. With the tuning
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function present, it would he excellent. Robert J. Newland Department of Physical Sciences Glassboro State College Glassboro. NJ 08028
Revlew I1 The intent of this program is t o simulate the operation of the Varian EM360 nuclear magnetic resonance spectrometer. The program can function as a substitute for a real instrument in nonreseareh situations. The program is aimed a t students who need t o use NMR spectra in their course work or research and must learn to run the instrument in order to produce useful spectra. The author states that this program is NOT a tutorial, and indeed, i t is not. A background in the theory and operation of an NMR is desirable prior t o attempting t o use this program. The program can he used t o teach students, who have never seen a real workine NMR. how to set uu an instrument and prhdtrre spectra. ~ n d e ; t h e ~circumstances c a runsidernhk investment of nn instructor's time rr required during the learning period and periodically thereafter. The program comes with a well-written User's Manual. The instructions for the installation of the program are clear and simple. Installation is quick and easy. After installation, the disk hoots directly. Anyone already familiar with the operation of a 60 mHz spectrometer should have no difficulty using the program. The area that requires the most time and effort to master is associating the appropriate keyboard keys with the the corresponding instrument controls. The User's Manual contains a summary of these in the Appendix. The User's Manual contains a narrativestvle . euide to the uroduction of an onscreen spectrum complete with integration. In thr course ofour exnmmntmn of the manud we found only one misleading direction. This was the msrructim for determinmg the positionofthe largest signal w that the amplr. tude of the s ~ e r t r u mc d d he adtuitcd fm maximum peak height. An experienced NMR operator will have no difficulty correctine.. the nrocedure. An erratum could he inserted intc the manual hy the instructor. \Vc rewwte the instructions m a n ehhrewated format for our student experimenters and corrected the procedure there. Little or no actual knowledge of computers is required to use the simulator. The program is very stable to erroneous inputs. Deliberate attempts to produce problems elicited either an irritating beep or nothing a t all. One cannot really consider this program in computer terms. The computer aspect virtually disappears and the system truly becomes an NMR. The size of the monitor used has an effect on how quickly the student sees the relationshim between a knoh dep~ctedon the screen, the ke! he ur she is pressmg uae that knub,and changes m the spectrum or positioning of peaks. A large screen monitor is an advantage but is not vital. The only aspect of the computer which remains is the need to press keys in order to "diddle the knobs". Students with extensive NMR experience found this distracting a t first, hut the tendency t o reach for a knob depicted on the screen soon disappeared. The less experienced students had little difficulty in thisareaandcaught onvery quick-
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ly. The key-to-knob relationships might he made clearer to the user by use of a template, or the author might consider labeling each knoh in the graphics presentation with the appropriate key. We exoerieneed no diffieultv in nroducine spectra onscreen. W e did freeze up the program with an attempt to print using the wrong command sequence. Once educated to the proper print procedure for the printer in use, this problem never recurred. The possibilities for use of this program in teaching NMR are limited only by the imagination of the instructor. Unknowns for any course involving identifications could be issued with the corresponding spectral file number. The spedral files are easily copied. One could create a group of Organic Qualitative analysis problems, include the appropriate physical properties of the compound, chemical test results, and the speetral file of the compound. With the simulatar available for s class, these problems could he issued either as homework or practice prohlems t o he done as needed. The student cauld run the spectrum, interpret the data, and identify the compound. Such problem sets could easily he designed to function as both instrument training and identification tutorials. The author states that a program of this type is best suited for use with advanced students who have had previous NMR experience. I concur. The program is of inestimable value where advanced students cannot he given adequate instrument time to become proficient. I t adds flexibility to the instructional process. Teaching and training need not be suspended when an older instrument goes down, or requires periodic maintenance. Use of the simulator as the total NMR experience for a student requires an investment of instructor time. There is no doubt that the program could he used in that capacity. Missing here is the experience of preparing a sample of adequate concentration, free of impurities and their attendant frustrations. Comments such as "this is great, now I won't get ink on my fingers trying to make that darned pen work" and "hey, no more ether and acetone peaks in my spectra" were typical. These are, of course, not resl flaws in this program. They are the neeessary evils of substituting a computer for an instrument that can he cranky a t times. The student reaction when introduced to the simulator can be best summarized in their words: "Oh. wow"and "all rieht!". We testedthr program onstudrntstaking Spectromrtric hlrrhodsof Identifirationand Hesearch 'l'rchniques in Oqnnic Chemirtry. two courses required for our chemistry majors. They loved it. After the initial introduction to the program it was bard to displace one group so that another group could use it. When our evaluation of the program had been completed we made the program available so that the students could take a crack at idmtit).ing nll the mmpuunds an thesample .spectradisk. S r e e n l t w k on the challenge with relish. Our normal sophomore organic labs hold 25studentsper section. Thesestudentsnever actuallv see an NMR sneetrometer although they are taught to the use reproductions of spectra for identification in the first
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(Continued on page A298) Number 11
November 1986
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