Mary Virginia Orna, O.S.U. College of New Rochelle New Rochelle. New York 10801
The Molecular Basis of Form and Color A chemistry course for art majors
Interest in the chemistry course for nonmajors has led to many recent innovations based upon special topics and approaches (1-4). During the past eight years, the chemistry faculty at the College of NewRochelle has designed anumber of courses which were meant to make students more aware of the world around them and the bearing that chemistry has on their lives, to look into some of the more fascinating areas which have developed in recent years, such as the chemistry of mental disease, chemical evolution, the chemical basis of some genetic diseases, the impact that stereochemistry has on our lives, and the chemistry of the environment, and to introduce students to some of the more recent technical and popular literature on these suhiects. - while these efforts enjoyed moderate degree of success and seemed to be in the mainstream of similar courses developed for the nonmajor nationwide, it was a t a faculty study day in 1972 that the art faculty pointed out that our approaches were too introspective. They felt that we were much too interested in showing nonchemists "what chemists do" and that perhaps nonchemists were not as interested in chemistry as chemists would like them to be. They suggested that, rather than trv to invite students into the wonderful world of chemisiry, we bring chemistry out into the world of the artist and see how chemical principles affect the materials and forms with which the artist works. The idea fascinated us, not only because we were heine invited to literallv turn ourselves inside out, hut because wesaw an opportunity to reach a student population we had never reached before. Although a large plurality of our undergraduate arts and sciences population is majoring in art, the art majors have traditionally avoided chemistry courses in fulfilling their six-credit science requirement because of fear of failure, a feeling of inadequacy or inability to cope with chemistry, and a complaint that thk chemistry courses offered had no bearing.on their goals as artists. In order to address these circumstances, the chemistry and art faculties conferred again in the spring of 1973 in order to seek an integrating principle upon which a chemistry course for art maiors could he based. After much thoueht and discussion, we concluded that two areas of vital interest to both chemist and artist were color and form. Followine this conference, I was given the task of developing a course which would he of hieh interest to art maiors. . . which would e" v e them some appreciation for the various media in which they work, and which would eive them a e w d chance of success reeardless of differences in scientific hackground and aptitude.>everal important initial decisions were made
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1) That the course be handled by one faculty member in order to provide an integrating experience for the student, but that
frequent consultation with the art and chemistry faculties take place and that provision for guest lecturers be made 2) That the course would not be limited to art majors, but that art majors would be encouraged to take it 3) That no previous chemistry course would be required 4) That the course would be a three-credit lecture course with heavy reliance upon lecture and laboratory demonstratians Thus "The Molecular Basis of Form and Color" was launched in the fall of 1973 and has been taught four times to a total student . ~onulation of about 120. The course content . described in the following paragraphs is the result of a two638 / Journal of Chemical Education
year evolutionary process which is by no means concluded. The course naturally fell into the two main divisions of color and form. The topics under color included an introduction to the nature of electromagnetic radiation, the place of the visible spectrum within the electromaenetic snectrum. and an introduction to color technology uzlizing the work bf ~ i l l m e ~ e r and Saltzman (5)as the chief reference. The technical aspects of color examined included the ways in which color could be modified by the object observed, by the spectral characteristics of the light falling upon it, and by the sensihivity of the detector to the various regions of the visible spectrum. Discussion then extended to the color of transparent and opaque objects, the detection and description of color, color-order systems, color measurement, and color mixing. After this rather lengthy introduction, durine which the students were encouraged~tospeculate on the findamental reasons why certain substances were colored and others were not, the chemistry of colur was introduced. Students were first inirintrd into the hasir farti (.I atomic structure and electronic configuration, with emphasis on the electronic transition within molecules and atoms as the phenomenon responsible for color perception. Sigma and pi bonding in organic molecules was discussed as an introduction to the color-producing and the effect electronic transitions in conjugated systems (6), of increasing the degree of conjugation was illustrated by the examples of the di~henvloolvenes and cvanine dves. There. " . . lationship herween mderular structure and cdor tor lack of it) was also illusrrated hvexaminine the acid and hase forms of phenolphthalein andbther indickors. Color in inoreanic compounds was approached via crvstal field splirring oithe d-orblrals in the fikt'roa of the transition mersl series. This also atiordcd an opnortunitv ro introdure some concepts of molecular geometry& he used in the second part of the course. Since the students, by this time. were aware that color in inorganic compounds couid be acco&ted for by the presence of partially filled d-orbitals on the central metal atom, they weresubsequently asked to try to account for the color ol~iervedin compounds where the metal atom had empty or rompletely tilled d-orbitals, e.g., Mn(VI1I,Cr(VI),and some cadmium and Icad compounds. This afforded an upporrunity to introduce charge transfer phenomena in both G a n i c and inorganic complexes and the idea of the hand gap in semiconducting materials. Further discussion of color centered upon the materials and techniuues used bv the artist. Some tonics discussed under dyes and pigments included solubility, refractive index, and the chelate formed between dves and mordants. A discussion (,iphotography included nor only an introduction to nxidarion and reduction within thecnntext of hlack and whiteand rolor photography but also infrared, ultraviolet, and fluorescence photography and holography. The focal point for the discussion of molecular form was materials science, particularly the nature of ceramics, glasses, metals, and polymers (7). he mole concept was introduced within the context of glaze calculations, and observable physical properties were-related to molecular geometry. The final portion of the course consisted of a brief introduction to museum science with emphasis upon the use of electromagnetic radiation to examine works of art. Included in the discussion were emission, infrared, gamma ray, ultraviolet, visible, spark source mass and atomic absorption
spectroscopy; other techniques discussed were thermoluminescence analysis, carbon-14 dating, and lead-210 dating. Conservation of works of art centered mainly upon works made of stone, wood, and metal. Although there was no laboratory period associated with the course, I found that the frequent lecture and lahoratory demonstrations I had planned were essential. Among the demonstrations were the dispersion of white light with a grating, the visible spectra of various cellophanes and dyes, flame tests for some of the more spectacularly colored elements such as lithium and strontium using the 10-cm flame of a n atomic absorption system, spectrophotometric demonstration of the Beer-Lamhert law, comparison of solutions of iodine in water and in carhon tetrachloride to illustrate the charge transfer phenomenon, the synthesis of methyl orange to illustrate color production by extended conjugation via an azo linkage, a comparison of the spectral distribution curve of an incandescent lamp with that of a sodium arc lamp, gamma ray spectroscopy with a sodium iodide detector, and the synthesis of cadmium sulfide coprecipitated with varying amounts of barium sulfate. Supplementing the lectures and demonstrations were several lectures cosponsored hy the campus ACS Student Affiliate Chapter, the art department, and the Westchester Chemical Society and included "The Inside Story of Color Photography" by Dr. John R. Thirtle of Eastman-Kodak and "Chemistry in the Service of Art" by Dr. Seymour Z. Lewin of New York University. Since no one textbook was available for this course, I prepared an extensive reading list of articles found mainly in Chemistry, the JOURNAL OF CHEMICAL EDUCATION, Scientific American, Analytical Chemistry and the twovolume symposium published by the Boston Museum of Fine Arts (8). Copies of this hihliography are available upon request. and students had the option of fulfilling some or all of the course requirements which included biweekly quizzes, an annotated bibliography of readings, a term paper or project,
and a final examination. Student interests were varied and term projects were completed in areas ranging from natural dyeing to infrared photography to holography. One of the great disadvantages of the course presently is that it is only a one-semester course, while the scope of the material lends itself to two or even three courses. Consequently, I have tried to he selective based upon the interests of the students taking the course in a particular semester. Student response to the course has been overwhelmingly enthusiastic. Although no converts have heen made to the ranks of chemistry, some students indicated an interest in taking additional chemistry courses and many students requested a "sequel" to the present course in order to do more in-depth studv-in certain areas of interest. lndreviewingthe topical development of the course, I realized that with the exce~tionof chemical eauilihrium and kinetics, all of the topics covered in the "traditional" introductorv chemistrv course were oresent. and that the former chemistry could easily he iniorporated into the discussion. And so. havina ventured forth into the world of art, we discover once again &at i t is the world of chemistry from a different point of view. Acknowledgment
Credit for the success of the course should go mainly to the students who so patiently helped me grope my way through the first semester and who so enthusiastically recommended it to their friends. I wish also to thank the members of the chemistry and art departments for their helpful suggestions and enthusiastic support of this project. Literature Cited (1) (21 (3) 141 (5)
Pau1i.G. H . , J CHEM. EDUC.,50, 210 11973).
Lesvers.D.R..J.CHEM. EDUC.,52.804 (19751.
Kopper, R., et al.. J. CHEM. EDUC., 52,733 (19751. L m e , D.G.,etal., J. CHEM. EDUC.,52,735 (19751. Bilimeyer, F. W.. Jr..snd Saltrman, M., "Principla af Calm techno lo^,^ Interscience Publishera, Ine., New York, 1966. (6) Jsffe, E. E., and Mmheli, W. J., Chemistry. 37,7 (Dee.. 1964). (7) Seienfilir American, 217 ISept, 19671, entire issue. (8) Young, W. J., (Editor), "Applicationof Science in Examinstionof Works ofArt." Museum of Fine Arts, Boston. 1967 and 1973.
Volume 53,Number lo, October 1976 / 639
