Elements of and in the Chemical Literature An Undergraduate Course Sabrina Godfrey Novick Hofstra University, Hempstead, NY 11550
Many undergraduate chemistry majors leave college with no clear idea of the chemistry of the elements and the periodic trends of chemical behavior. This is partly due to the increasing complexity and sophistication of inorganic and physical chemistry ( I ) . As a result, the focus of general chemistry textbooks has shifted away from descriptive chemistry to include such topics a s atomic orbital theory, chemical kinetics, and electrochemistry. I n order to balance this shift, many general chemistry textbooks still include chapters on descriptive chemistry of the elements. Unfortunately. the time period of a class is not a s elastic a s the length of textbook;~hesedescripive chemistry chapters are not routinelv included in some general chemistrv classes due to a lack of time. However, coverage of descriptive chemistry of the elements has been included by the American Chemical Society (ACS) in its latest guidelines for ACS-accredited undergraduate degrees (2). At the same time, the information explosion has led to greater complexity i n literature searching. As a consequence, students need more instruction i n how to search eflicicntly for mfonnation on a spwific topic. The advent of cornouterizcd databases. such a s CAS On-line and Scfence cita>ion Index (SCI) on CD-ROM, has increased the ability of a n individual to search quickly for information on a topic. However, these databases and the traditional literature are of limited utility if the person does not know how to use them. The recognition of the need to introduce students to the chemical literature and computerized databases i s evident in articles published in this Journal ( 3 4 ) The ACS also has recognized this need in its latest guidelines for ACS-accredited undergraduate degrees (6). Unfortunately, introduction to the chemical literature can be a dry exercise for the student. A n alternate approach involves the learning of how to use the chemical literature woven into a discussion of the chemistry of the elements. In this way, use of the chemical literature can be presented a s a skill needed to obtain the goal of information about an element. This is more in accordance with the way literature searching usually is approached and i t provides a vehicle for the presentation of topics often ignored in general chemistry courses due to the press of time. A particular advantage of this course is that the elements chosen for in-depth study can be selected from those chapters that the instructor knows have been omitted i n the general chemistry course. This course is suitable for sophomores through seniors with only general chemistry as a prerequisite. The use of computer programs based on the periodic table allows the student to explore the trends of properties among the elements. Finally, the student gets to exercise these new skills and knowledge in a game, a 15minute oral presentation, and a term paper on the chemistry of a n element. This provides the potential for 109 different topics, one for each element in the periodic table, with the choice of seminar and term paper topic tailored to the knowledge level of the student.
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Outline of the Course I. lntroduction to the Literature
Types of Literature 1. Primary literature: Journal articles 2. Secondary literature: Books and reference material B. Discussion of Some Secondary Literature 1. Beilstein 2. Gmelin 3. Reagents for Organic Synthesis by Fieser and Fieser 4. Inorganic Syntheses (various editors) C. lntroduction to reference databases 1. Chemical Abstracts 2. CAS On-line 3. Science Citation lndex 4. Others (e.g., lndex Medicus)
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11. Interactive Computer Databases of the Elements A. KC? Discoverer ( 7 ~ 6. The Periodic Table Stack (8) C. MacMendeieev (5) 117. Discussion of the Elements A. History of the Elements and the Periodic Table 8. Nuclear Chemistry C. X-Ray Crystallography and Crystal Structures of the Elements D. Safetyand the Elements; Material Safety Data Sheets (MSDS) F Industrial Uses of Selected Elements G. Biochemical Uses of Selected Elements IV. The Chemical Detective Game
V. Seminars Discussion of the Course The course opens with a discussion of the chemical literature. The distinction between primary literature and secondary literature is covered. The endnote method of referencing used in the majority of chemical journals i s presented. Students are introduced to the major secondary sources, namely Beilstein, Gmelin, Reagents for Organic Synthesis, and Inorganic Syntheses, and shown where they are in the library. A homework exercise is assigned that has the students use each of these references. A sample homework exercise (Homework 1) is shown in Table 1. The course then t u r n s to t h e introduction of the major chemical databases. Chemical Abstracts (CAI a n d Science Citation Index (SCI) a r e discussed. The purpose of CA a s a cross-referenced librarv of abstracted chemical literature i s presented along with the organization of CA accordine to volume number and abstract number. Students areshown the types of indices, their uses, and t h e decennial indices. SCI i s introduced a s a database used to determine if more recent literature has been published on a topic. The different uses of the databases are stressed. CA can be used to search backward through time and SCI can be used to search forward through time. A homework problem based on author in-
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Table 1. List of the Assigned Homework Sets 1 . Use of Beilstein, Reagents for Organic Synthesis and Inorganic Syntheses
Homework I 1. Use Beilstein to find out t h e saluhility of caffeine (Ger. kaffein) i n water and chloroform. Report t h e solubilities (don't forget units!) along with t h e literature reference for this information and the system number for caffeine. Include the location of caffeine i n t h e original handbook as well as in all relevant supplements. 2. Locate the synthesis of mevalonalaetone in Fieser and Fieser. Write a brief synopsis of the synthesis with balanced chemical equations and any safety precautions. Include a bibliography of relevant references. Answer the question: What is the importance of this molecule? 3. Write up a brief description of the synthesis of polycrystalline lithium nitride using Inorganic Syntheses. Include balanced chemical equations, any safety precautions a n d a bibliography of relevant references. Answer the question: What is the importance of this material?
2. Use of Chemical Abstracts and Science Citation Index Homework 2 There are more living chemists today than ever before in history. The names of those chemists writing and publishing articles represent every nationality. I wonder if there is any chemist whose surname is the same as the name of your element, like Long John Silver (!). Use the Author Index of Volume 115 of Chemical Abstracts to investigate this possibility. Begin by finding all entries for authors whose last name is the same as the name of your element. If there are none, find the position in alphahetical order where yaur element's name should appear. Write down the names that appear just before and after this place in the list and base your answers to the following questions on these two names. Far example, Aaron Gald, Bob Gold, . . . Zeke Gold all have the same last name Gald but John Irom and Mary Iraos could he used if no chemist named Iron is listed. 1. How many chemists have you found? List their names (no mare than 6). 2. How many articles did each of these authors publish? 3. Give full bibliographic data and a short description of the first article that you have found. 4. Use the Science Citation Index to determine if any articles by the first author listed in one have been referenced. If not, continue dawn the list until you are successful. Give full bibliographic data far the most cited article and the number of citations found.
3. Use of CAS On-line and Chemical Abstracts
Homework 3 Use CAS On-line and Chemical Abstracts to answer the following questions. Using the LCA learning file, determine how many articles were published from 1969-1984 on five of the following subjects and your element. Give full bibliographic data, including a summary of the abstract, for one article in each category. Submit a copy of the printout from the CAS On-line session along with your report.
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a. catalysis h. corrosion e. radioactivity d. glass or pottery e. magnets or superconductivity f. electronic devices g. geology or geochemistry h. astronomy i. ecology and pollution
4. Use of Interactive Computer Databases : (KC?Discoverer, The Periodic Table Stack, and MacMendeleev).
Homework 4 Using KC?Discoverer or a combination of the Periodic Table Stack and MacMendeleev, complete the tutorial, then answer the questions below. 1. At what temperature does your element melt? 2. Camvare the relative abundance6 in the cosmos of the
riad and your element. Comment on trends observed. Hand in graph or table of data. 4. Plat the numher of isotopes versus atomic number for all of the elements and discuss any trend observed. How does the number of isotopes of your element eompare?
5. Discussion of an MSDS and Questions about Assigned Readings in General Chemistry Textbook.
Homework 5 1. MSDS: Every chemistry department has a compilation of MSDS. Summarize the MSDS of the alphabetically first compound that contains yaur element, including the chemical formula, CAS registry number, precautionary measures, reactivity data, and First Aid information. If no such MSDS exists, see yaur instructor. Where do you encounter this compound in everyday life? How dangerous do you think this compound is? 2. Nuclear Chemistry: The halogen astatine can only he obtained artificially through bombardment. I t has been found to be useful for the treatment of certain types of cancer of the thyroid gland, for i t migrates to Why is that true?). this gland just as iodine does (Q: 21185Atis an a particle emitter with a half-life of 7.21 hours. If a sample containing 0.100 mg of 21185Atis eiven to a oersan a t 9 a.m. one mornine. -. haw much asr m n r wll remaln in rhc hod? nt 9 n rn rhc fulowng rnururng' Include the hslanccd nurlrnr rquatlun. 3. C w r d l m r w n C h e m l l t r y : Ammo a a d s e m act a s ligands toward transition metal ions. The simplest amino acid is glyeine (H2NCH2COOH).Draw a strueture of the glycinate anion, H2NCH2COO-acting as a hidentate ligand. Draw the structural isomers of the square planar Cu(H2NCH2COO),. 4. Main Group Chemistry: One discipline in inorganic chemistry is the study of nonmetals. Often researchers attempt to mimic organic molecular structures with inorganic molecules. In Inorganic Syntheses, volume 9 on page 98 there is a report of the synthesis of S4Ne ~
~~
(a) Propose a structure far S4N4;write the Lewis structure for it. What hydrocarbon does it resemble? (bl How does the reactivity of S4N4compare with that of the analogous hydrocarhon?
Table 2. Elements and Authors with Similar or Identical Surnames as Found in the Vol. 115 Author Index of ChemicalAbstracts
Element Hydrogena Boron Carbona Oxygena Sulfura Potassium Calciuma Titanium
Name of author Hyde, Bruce G. Boron, Piotr Carbon, Claude Oxtoby, David W. Suifab. Yousif Potashnik, G. Calcinaro, F. Titani, Koiti
Element /Zinca Arsenic Silver
Name of author Zinchenko, A. D. Arsenijevic, Lucia Silver, Anne C. Tln Tin, Chin Che Iodinea lokovskii, S. A. Tungsten Tungol, Mary W. Golda Gold, A. Mercury Mercuri, Nicoia Biagio Leada Leadbeater, M. L. Bismuth Bismuth, Janine Radium Radionov, A. V.
Table 4. General Seminar and Term Paper Topics
General Seminar and Term Paper Topics (X = an element) The Industrial Uses of X Chemical Analvsis of X The Roe of X ;n - v ng Cells, or The B ochern!stry of X Tne Roe of X In S~percond~clors Meo~calJses of Elemenl X Medical Uses of Radioactive Element X Bonding in the Element X X in the Environment The Chemistry of X in Volcanoes The Occurrence and importance of X in Nature (excluding C, N, 0, s. PI ~ i e i e nXt and its Relation to the Other Elements in Its Group
Chromiuma Chromik, Stefan irona iron, Albert Nickela Nickel. A. Coppep Copper, Elizabeth F. 'Elements with specifictopics in Table 5.
readings can come from General Chemistry textbooks (Table 3). The topics listed in section I11 of the outline are representative. A flexible number of lecture ~ e r i o d can s be devoted to this section of the course dependig on the amount of time required for the student seminars. The goal is to cover a s much descriptive chemistry a s time ;ill allow, ranging over the periodic table in several contexts. Additional topics can be covered as needed to satisfy student dexes of CA give each student experience i n using these interests and meet the goals of the individual instructor. databases. Each student takes t h e name oftheir assigned (See Table 3.) element and triestofindifanyonewiththesurnameofthe Throughout this section of the course, students are introelement(orasimilarsnrname)haspublishedintherecent duced to a group of computer programs that serve as interchemical literature (see Homework 2 i n Table 1). The active databases of element information. The most useful program is KC?Discoverer (71, which runs on PC systems. names of several chemists obtained by this search a r e On our campus, i t has been installed on a group of PC's in listedinTable2. a central c o m ~ u t e rfacilitv. orovidine for readv access bv To learn how to perform searches by subject using CAS way to get students students. ~ ~ f ~ i s c o v e;s'i r e powerfz r On-line, the students spend one lecture period in the lito think about similarities and differences between and brary with a n expert librarian who first explains CAS Onamong elements by selective searching and graphing of line. then demonstrates how to use the database. Students data. Also, the graphing of data provides a picture for the are given one homework set based upon their assigned elestudents in which general trends can be recognized easily. ment (see Homework 3 in Table 1) and are encouraeed to KC?Discoverer includes a pictorial representation of the use CAS On-line to prepare for their seminar and term paunit cell of every crystalline element, aiding the discussion per. At first, this part of the course did not go a s smoothly of the crystal structures of the elements. In this course, the as exoected. Students a t our institution are restricted to computer programs are used during lecture periods by the u s i n g On-line ~ ~ ~ during academic discount hours, which instructor. The computer is attached to a liquid crystal disseverelv limited the abilitv of the exoert librarian to over~ l a that v is then olaced on a n overhead oroiector In this " see the students. Also, the students did not demonstrate &a$, the s t u d e n t s ' a c t u a ~ lsee ~ the programs in action bean understanding of Boolean search parameters 'and' and fore trvina to use them alone. 'or', often using them incorrectly. Accordingly, we now pre~ e c & s e o u rdepartment is mixed between PC users and sent a specific search with emphasis on the thought procMacintosh users. two similar Droerams that run on Maciness of the searcher and the process executed by CAS Ontoshes are introduced. The ~t!hodic'~:ih~e Stack 18,la a 11"line. pwvard stack in which element inform:ition is stored. EleWhile literature searches are proceeding, additional readments can be searched for a range of properties, and ings on the chemistry of the elements are assigned. These displayed as a list, or highlighted on a periodic table. As in KC?Discoverer, element information Table 3. Relevant Reading Assignments is available on different screens a s well as a ~ i c from Three Major General Chemistry Textbooks torial representation of the unit cell of every crystalline element. The Periodic Table Stack is deThis reading assignment in a general chemistry textbook is meant to complement s i g n e d a s t h e Macintosh version of the lectures and cover topics that are important, but not included in the lectures. Problems in homework #5 will be based on this material. Read the relevant chap- KC?Discoverer b u t suffers from one serious drawback: there a r e no graphing capabilities ters in the book available to vou. built into t h e program. O n t h e other h a n d , Textbook Topic MacMendeleev (9)is almost exclusively centered Chapters on graphical representation of element properZumdahl Ebbing Mortimer ties. Screens of element information a r e not (2nd ed.) (3rd ed.) (5th ed.) available for individual viewing. Combining these two programs, the capabilities of KC? Dis1. Review of atomic structure and periodicity 7 8 4 coverer can be reproduced on a Macintosh. Properties of the elements along with data-gath2. Chemistry of the elements 18.19.21 2 2 19-22 erine skills are emphasized in a game called 'The 3. Transition metal complexes 20 23 2324
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4. Nuclear Chemistry
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The Chemical Detective Game Rules o f the Game:
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2. A 10-min~te q~estionsession wll oe al oleo for eacn myslery e ement Eacn team wil . ask qJeslaons n rolatlon. Acopy of tne CRC HandoooK 01 Chemrstry and Physrcs s auah able to each team as a reference. Example questions with answers for the mystery element Mo are: Question (a) Is it a metal, nonmetal, or metalloid? (b) What is its atomic number? (c) What is its melting point? (d) What row of the Periodic table contains this element? (e) What is the element's highest common oxidation state? (f) Does it have a basic or acidic oxide? (g) What is the formula of a chloride? (h) Is it conductive? (i) Is it radioactive? 4i)What is its industrial imoortance?
Answer A metal A number between 1 and 109 Over 200 OC Not rows one or two +6 Acidic (Molybdic Acid) XCls Yes No . . As a catalyst in t he !of petroleum
Note that more specific questions receive less helpful answers. More general questions based on observable or measureabie properties can be given more specific answers. The instructor's objective is to maximize the amount of deductive reasoning required. 3 At tne en0 ot 10 m n, each team can suom t a gdess as to tne den1 ly of !he myslery element Flve polnls w I oe awaroco for a correct answer. two po nts w I oc deoJcte0 for an ncorrect answer, and no po nls u oe awarded t no answer s sdom !led 4 A1 !he end of tne per od. members of tne w nnmq team w be awardeo prlzes Gooo .cd
I Rules of the "Chemical Detective" game.
teams o f three t o four students each, a n d each t e a m i s p r o v i d e d with a CRC Handbook of Chemistry a n d Physics. The instructor selects an element and the students are allowed a l o m i n u t e question session o n the m y s t e w element. A handout i s providedwithexample questions and the rules of the game. The students then submit a n d a r e rewarded five points for a right answer a n d m i n u s two points for ;wrong answer. A t the end o f the lecture period. the winning team i s presented with prizes. T h e students enioved t h i s g a m e g r e a t l y , f u r i o u s l y flipping t h r o w h the CRC,discussing the passibili'iies a m o n g t h e m s e l v e s a n d cheering each other on. E a r l y in the course, students are required to select a n element for presentation as a 1 6 m i n u t e seminar and as a five- t o 10-page term paper. A l i s t o f topics i s distributed for students t o choose from (Table 41, although they also are given the freedom to choose a topic n o t o n the list. Subsequent performance b y the students emphasized the need for one major reference to be provided b y t h e i n s t r u c t o r t o h e l p them get started. E v e n with extensive discussion of chemical l i t e r a t u r e , some students still h a d trouble get-
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Table 5. List of Specific Topics for Seminars and Term papers along with One Major Reference Each SuggestedTopics
Major Reference
1. Magnetic Resonance Imaging (MRI): 'H NMR of the body
Morris, P. G. Nuclear Magnetic Resonance imaging in Medicine and Biology. Clarendon Press: Oxford. 1986.
2. Fullerenes: a third form of elemental carbon
Hammond, G. S.; Kuck. V. J. Fullerenes, ACS Symposium Series 481. American Chemical Society: Washington, DC, 1992.
3. The role of oxygen in superconductors
Nelson. D. L.; George, T. F Chemistty of High-Temperature Superconductors, Vols 1-11, The American Chemical Society: Los Angeles, CA, 1988.
4. The chemistry of sulfur in volcanoes
MacDonald, Gordon A. Volcanoes. Prentice-Hall Press, 1972.
5 Troponin C and calcium
Harrison, P. Metaiioproteins, P a r t 2 Metal Proteins with Non-redox Roles, Vol. 2. Verlag Chemie: Weinheim, Ger, 1985, pp 65-112.
6. Chromium and the multiple bond: Fact or fiction?
Cotton, F. A,; Walton, R. A. Multiple Bonds between MetaiAtoms. J. Wiley and Sons: New Yoh, 1982.
7. iron-containingcytochromes
Dickerson, R. E. Sci. Am. 1980,242, 137.
8. Occurrence and importance of iron in nature
Daniels, L.; Belay, N.; Rajagopal, B. S.; Weimer, P. Science 1987, 237, 509.
9. Nickel-Iron Hydrogenases
Lancaster, J. R., Ed. The Bioinorganic Chemistryof Nickel. VCH Publishers, Inc.: New York, 1988.
10. The role of copper in copper-zinc superoxide dismutase (Cu-Zn SOD)
Tainer, J. A.; Getzoff, E. D.; Richardson, J. S.: Richardson, D. C. Nature 1980, 306,284.
11. The role of zinc in carboxypeptidase A
Stryer, Lubert. Biochemisfw 3rd ed. W. H. Freeman and Co., 1989, pp 215-220
12. Medical uses of radioactive iodine
Spencer, R. P. NuclearMedicine. 2nd ed. Medical Examination Pub. Co.. Inc.: New York, 1980, pp 67-96.
13. Occurrence and importance of gold in nature
Lippard, Stephen J. Platinum. Goldandofher Metal Chemotherapeutic Agents. American Chemical Society: Los Angeles, 1983.
14. Group 4Aelements and the "inert oair effect" of lead
Cotton. F. A.; Wilkinson, G. Advanced inorganic Chemistry.4th ed. J. Wiley and Sons: New York, 1980, Chapter 12.
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ting started in the search for information on a topic. A list of spec& topics with references is given in Table 5. Because many of the chemistry majors a t this institution have a strong interest in biochemistry or medicine, biologically relevant topics are the most popular. For the seminar, each student must submit an outline of the talk tu,o wwks in advance along with live references, some of which have to be from the primary Ilterature. A s an exercit!, wrch student is asked to create and distribute to the class an abstract of thc! scmlnar, with references, OII the day of hisher seminar. In this way, the progress of the student can be monitored. Each student is allotted 15 minutes for the seminar and five minutes for questions. I n a typical hour lecture period, three students can be accommodated. The qualitv of seminars varied aeatlv . from student to student, emphasizing the need for such an experience. The quality of the papers varied as well. Apparently the most difficult part of the process for the students is attention to stylistic detail. Correctly referencing their sources proved difficult for most students. Requirement of the purchase of the ACS Style Guide (10)and distribution of a sample paper helps alleviate these difficulties. Attention to content and presentation of material is generally good. Conclusion A course designed to introduce undergraduates to the chemical literature in the context of the studs of the elements has been presented. Se;rrching the chemical literature is introduced a s a skill needed to obtain the goal of information ahout an element. Chapters in mosl general chemistry textbooks not n~~rmnllv covered in lecturr i~rt! examined and discussed. Interactive computer databases about the elements are utilized. Homework sets are provided to develop these skills and broaden the student's knowledge of the chemistry of the elements. Students are given the opportunity of exercising these new skills and
demonstrating new knowledge via a game, a short oral presentation, and a term paper. This course can be varied in length and depth to accommodate different total semester hours available. The course could be oared down bv reducine the number of homework sets a i d changing thk emphasis of the chemical literature homework sets to that of the topic selected by the student. For example, the third homework set can be chaneed to a search on CAS On-line of kevwords relevant to the student's topic. I n that way, the focis would be narrowed to the todc of the seminar and paper, reauirina less totid enirn by the student. As mentlon.ed'in the>iscu&on, the number of topici listed in st,ction 111 of the outline and depth of discussion can be adjusted to the available time. In contrast, the course could be expanded by providing more homework sets and greater discussion of topics listed in section I11 of the outline and additional topics. Acknowledgment I would like to thank Dennis Ryan for his help in developing this course. Literature Cited 1 . Garafolo, E;LoPresti. V. J Chem. Educ 199%. 70,352-359. undprgmdunie ~ ~ ~ f e s s i o~ndaui c o t i n ni n chemistry: cuideiims and Euoluorion Pmceddums, Fall 1992. Committee on Professional Raining. American Chemical Souety, Washington, DC. 1992, p 8. 3. Gorin. G. J. Chem. Edue.1991,68,757-759.
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4. Somerv3le.A. N. J. Chem. Educ1991.68.842853. 5. Abrash. H I . J. Chrm. Educ.I992,69;143-146. 6. Underpraduate Professional Education in Chemistry: Guidelines and Evaluation Pmredures, Fall 1992. Committee on Professional Training, American Chemical Society, Wsshington, DC, 1992. p 12. 7. Fen&A ; Moore. J.; Hamood, W. s.;G8yhart.R.B.The Javrnai o/Chrmie.i Edumtion Safliuam, Volume 18. No. 1. American Chemical Societv: Washineton. DC.
. ...... ..... 8. Farris, M. W. The Journoi of Chemical Edueviion Safiioa~.Volume IC, No. 1. American Chemical Sooety.Waahmgtan, DC, December 1989. 9. Tnn@ Soltware:Campton. NH, 1990. 10. Dodd. J. S., Ed. The ACS Siyie Quid-. American Chemical Society: Washington. DC,
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