perhaps, a t its worst. It is a gift horse which, when looked straight in the mouth, is found to have false teeth. There is no physical validity to it even though it is mathematically convenient and L'works" UP to a point. Thus, the conceptually simple picture which has traditionally been employed in introducing the idea of d orbital splitting can no longer be used unless one is willing to perpetrate a deliberate and conscious deception. Naturally, it has long been recognized that the crystal field theory could not be taken literally; that is, that a purely electrostatic treatment of complexes and crystals which took no account a t all of covalent character in the metal-ligand bonds was not entirely correct. But it was generally assumed that the electrostatic approach was partially or qualitatively, perhaps, in some cases, even semiquantitatively valid, and thus perfectly legitimate for use a t least as a first approximation, or as a half truth which further study would not contradict, but merely qualify and enlarge upon. I believe that most teachers a t some time find it necessary to use the general approach of beginning a topic with a facile half truth and that this is fair practice. I do not believe, however, that it is ever justified
to present, consciously, a facile untruth, however much it may help in "putting the subject across." I hope that readers who agree with this premise will find this discussion useful in avoiding some of the untruths about ligand field theory. Literature Cited
J., Z. Phy~ik.,58,205 (1929). (1) BECQUEREL, 12) BETHE.H.. Ann. Phvsik 151. 3. 135 11929) BAL~AUS;N,C. J.; K&" ~ a n s k b~ l d m s k a b . Selskab, Mat. Fys. Medd., 29, No. 4 (1954). The qualitative argument given here is based on the calculations of KLEINER,W. H., J . C h m . Phys., 20, 1784 A. J., A N D WATSON, R. E., P h y ~ . (1952) and FREEMAN, Rev., 120, 1254 (1960). R., AND SCHMIDTKE, J~GENSEN C., K., PAPPALARDO, H.-H.. J. Chem. Phvs.. 39.1422 11963). ~ N SUGANO,'~.,
D &ULM~;
R. G:, phis. Rev., 130, 517
110fi3iRi.
\ - - ~ - , ~
(8) HUSH,N. S., AND PRYW,N. H. L., J. Chem. Phys., 28, 244 (1958). (9) BLAKE,A. B., AND COTTON,F. A., Inorg. Chem., 3, 5 (1964). (10) MCCLURE,D. S., Phys. Chem. Solida, 3, 311 (1957); DuNITZ, J. D., AND ORGEL,L. E.,Phys. Chem. Solids, 3, 318 (1957).
Qualitative Organic (?) Chemistry In a certain chemistry building there are five labs, all in a. row, each painted a different color and each containing a special item of apparatus. A different chemist works in each lab and keeps the main stock of one solvent and one reagent. The following information is sufficientto tell who has the acetone and where the gas chromatograph is located. (Struggle a bit. We'll tell you next month.) Fisher works in the red lab. Grignard has the infrared spectrophotometer. Ethyl ether is in the green lab. Kekule has the benzene. The green lab is immediately to the right (your left) of the ivory lab. The chemist with the phenylhydrazine has the magnetic stirrer. The iron (111) chloride solution is in the yellow lab. The alcohol is in the middle lab. Friedel works in the first lab on the left. The chemist who has the phenyl isocyanate works in the lab with the sublimation furnace. Iron(II1) chloride solution is kept in the lab next to the lab with the sublimntion furnace. Tollens reagent is in the same lilh as the chloroform. Lucss keeps the supply of Lueas reagent. Friedel works next to the blue lab. Submitted by PROF.JAMESG. TRAYNHAM LOGISIANA STATEUNIVERSITY
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Journal o f Chemicol Education
