Kivhnrti* 3Iaial Aticirens · · · Unsolved Problems nl Mini 11! πι I Chemistry LINUS PAULING, California IiisliLuleof Technology, Pasadena, Calif.
Linus Pauling, Theodore William Richards JVEcdalist for 1947, has boron distance is about 1.85 A. 1 think made notable contributions to quantum mcch-aiiics, valence theory, that this structure may be described in crystal structure, and also to rice Iron diffraction various ways, as, for example, by saying that there is a protonated double bond (E. Wiberg, K. S. Pitzer). My own As l CONSIDER our present knowledge of sources about, the activation of chloro inclination is to describe the molecule structural chemistry, and comparu it with phyll. Bv obtaining a copy of a patent 1 in terms of resonating bonds. If it is that of 25 years ago, I am astonished at tin» lea-ned tlmt chlorophyll is activated by assumed that the bonds between the progress that has been made, and almost formaldehyde- This type of activation methyl carbon atoms and the boron atoms tempted to feel that the major problems seems to differ somewhat from ordinary are single covalent bonds, then there are have been solved, and that the future de types, because - a groat many molecules of enough electrons for two additional elec velopments of structural chemistry may be formaldehyde arc required for the activa tron-pair bonds to be formed, and there far less interesting than the developments tion of each niolecule of chlorophyll. The are five positions available for these bonds, which wc have watched during the past thought has occurred to me that the signif one between two boron atoms, and four quarter century. Twenty-five years ago icant phcnonicnon may really be one of between boron and hydrogen atoms. If we had no precise knowledge (A' inter deactivation, rather than activation, and these bonds resonate equally among atomic distances and bond angles in mole that the formaldehyde may be acting in a these positions, each position would be cules, and the understanding; of the nature way similar to that effective when it is occupied by a bond with bond number 0.4. of the forces responsible, for chemical com used in enibal niing fluid. With the relation which I have recently bination was very vague. Now the de Some I'tissli rig Small Problems suggested between interatomic distance tailed atomic structures of many hundreds and bond number, we then predict the There are many molecules, even rather of molecules and thousands of crystals are distances B-B = 1.85 Α., exactly the value simple ones, whose structures have not yet known, and the theory of valence and the reported from tfie electron-diffraction in chemical bond, with its basis in quantum been determined reliably, or about which vestigation, and B-H = 1.35 A. mechanics, has developed far enough to there exists a difference of opinion. One permit reliable predictions to be made in of these is tho ozone» molecule. Spectro A problem of a different sort in the field many cases. scopic data liavo been interpreted in re of inorganic chemistry is that of explaining Despite this progress, there remain cent years as showing t hat the ozone mole the nonexistence of perbromic acid. It many unsolved problems. Γ shall discuss cule consists of two oxygen atoms close might be suggested that bromine lies just some of these problems, dividing them into together, and. a third one farther away, in the middle of the transition from a sta four successive categories. and equidistant from the first two. This ble acid with coordination number 4, such structure would bo described as an oxygen as perchloric acid, HCIO4, to a stable acid Comic-Strip Science molecule with a third oxygen atom only with coordination number 6, such as para- In our present atomic age everyone is loosely bonded toit- The alternative struc periodic acid, ΗόΙΟβ- However, the exist continually made aware of t he existence of ture of ozone (analogous to the structure ence of salts of periodic acid with coordina atoms and molecules. Atomic fission and of sulfur dioxide) is that in which a central tion number 4, such as KI04, renders this other atomic phenomena are presented to oxygen atom is attached to two equidis explanation unsatisfactory. the younger generation in the comic pa tant oxygen atoms, with a bond angle of Another interesting problem in inorganic pers, and molecules and their properties about 125°, corresponding to the presence chemistry is that of the structure of uni- are introduced to us in advertisements. of a double bond îind a single bond, in negative rhenium. The discovery by G. The schoolboy now accepts the existence resonance. This structure, originally sug E. F. Lundell (β) that perrhenate ion in sul of atoms and molecules without question, gested by (î. X. Lewis and substantiated furic acid solution is reduced by passage and he is apt to have a reasonably good by the elect rotwlifffaction investigation through a Jones reductor by eight stages, understanding of their properties and sig carried out 1>3' W. Shand, Jv., and R. A. to rhenium with oxidation number — 1, nificance before undertaking the study of Spun· U), is -t.hu correct, one, but it is diffi carries great interest because this is the science in school. I have noticed that the cult to understand the contradictory con only known occurrence of a metal with advertisements in our national magazines clusions reached by the spectroscopic in negative oxidation number, although sometimes present problems, problems vestigators. compounds of metals with oxidation num that have remained unsolved. One of the Another molecule about which there has ber 0, such as the.nickel cyanide complex 4 problems which has interested me is the been a différend! of opinion is diborane, Ni(CN)4 ~, have been made. The only nature of "pin-point carbonatiou." I Bulle. The alternative structures for this explanation which I have been able to have been given the impression that this molecule are a structure similar to ethane, formulate for the existence of rhenium in r phenomenon is interesting and valuable, and a struct ure in which two li3 drogen this negative oxidation state is that the but I have not been able to discover its atoms are sbtared between the two boron rhenium ion exists in this system with an nature. Another phenomenon of which I atoms. The exprri mental evidence favors electronic structure similar to that of bi- have tried, without success, to obtain an the second of those structures. In particu positive platinum, which is isoelectronic understanding is the "activation" of lar, an electron-diffraction investigation with uninegative rhenium. Bipositive chlorophyll irt the household deodorizer of tetraniethvldiborane carried out by V. platinum exists only in complexes in which "Airwick." The selection of chlorophyll Schomaker and YV. Shand, Jr., provides it forms four covalent bonds, with four to be used in this preparation is no doubt strong support for this structure. These groups, arranged in a coplanar square to be attributed to its well-known ability investigators have found that ' the {our about it. Accordingly, it seems likely that to purify the air by converting carbon methyl groups are essentially coplanar uninegative rhenium exists in the same dioxide to oxygen. I have been interested with the t\*ro boron atoms, with bond state, and it may be that the four groups in the properties of chlorophyll for some angles of approximately 120° and boron- which it coordinates about itself at the time, and I had not heard from other carbon distance of 1.59 A. The boron- corners of a square are four wrater mole-
2970 CHEMICAL AND ENGINEERING NEWS eules\ Experimental verification of this nance of the electron pairs among sev each bond to the t.lirt*e chlorine atoms held suggestion has not yet been obtained; the eral alternative positions occurs with an in common is similarly calculated to be problem is now being attacked by 10. increase in the number of bond positions 0.5, and that of the? bonds to the other Maun. above the number of bond orbitals. This chlorine atoms 0.7. The total number of interesting general principle has not yet bonds formed by the tungsten atom is thus Some Larger Problems been given quantitative; formulation (of calculated to be soinething over 5. The the amount of increase in coordination crystals are dianutgrietic, and the bond There are a number of problems dealing number in relation to the amount of elec struct ures which miglH be proposed for t he with the structural chemistry of groups of tron deficiency) or theoretical justification. complex of two tungsten atoms could substances which merit mention. Another question in the field of inorganic accordingly be written [:W— W:, :\V= First, there is the question of the ob chemistry about which little is known at W, W=W:]. Th« crystal structure served increase in coordination number of present is that of the extent to which co- of K3W2CI9 as reported by lirosset has re atoms which do not have a sufficiently valent bonds between metal atoms occur cently been verified in our laboratories by large complement of electrons to permit in nonmetallic compounds. I had thought Jurg Waser. the formation of electron-pair bonds in that every chemist was familiar with one A closely similar structure; has been number permitted by the available bond of the substances in which these bonds found for ironennoiicarbonylby Powell and orbitals. The boron hydrides, if we as occur but a year or so ago I was aston Kwens (β). The observed diamagnetism sume the new structures to be correct, are ished to learn, while telling a young man of this substance can he explained by tl*e examples of this situation. Boron in B1I3 who had recently received his doctor's formation of a covalc.Mil bond between the has only three valence electrons, permit degree in chemistry about the eimeachln- two iron atoms, ιιικΓ t lie iron-iron dis ting it to form three single covalent bonds. roditungster complex ion, that he could tance, 2.4(i Α., is only slightly larger than As a first-row element it has available for not think of any common representative thai expected fornsi righ* covalent bond. bond formation four bond orbittds. It of this class of substances and, moreover, The structure reportod for crystals of might be expected that a polymer would that he did not know what calomel is or molybdenum dioxide and tungsten dioxide be formed, diborane, in which all four bond what metals appear in the first group of by Arne Magneli(7)also shows the presence orbitals are used, with.the available elec the scheme of qualitat ive analysis. of bonds betweenIlit* metal atoms. These tron pairs resonating among t lie bond posi The existence of the mercury-mercury crystals have a distorted rutile structure, tions; this description applies to the + bond in the mercurous ion, Ilg2 *" , and in in which each metal atom is surrounded ethanelike structure for diborano. How molecules such as CI—ilg—llg—CI has by an octahedron of oxygen atoms. The ever, the alternative and pre«uma.l>ly cor been recognized for many years, but. until distortion from the ideal structure is of rect structure is one in which the» bonds recently other examples of such bonds had such a nature as to bring two molybdenum resonate among five bond positions about not been reported. The complex ion or tungsten atoms very close together to each boron atom. Similarly, in calcium W2CI9 was discovered to have such a form a pair of atoms 2.48 A. apart, t he cor hexaboride, in which there are enough elec structure a few years ago by Cyrill Bros responding edge sha,rcd by the two octa trons (assuming the presence of calcium se t (5), when he determined the crystal hedra being greatly Icsngt hened. The bond ion) for 3V3 electron-pair bonds per boron structure of K3W2CI9 and isomorphous sub number calculated from this interatomic atom, the configuration of the boron stances. This complex ion has a configura distance is 1.47, suggesting that there is an framework is such that each boron atom tion obtained by sharing a face between effort by each quadrivalent molybdenum is bonded to five boron neighbors, in two W016 octahedra. The triangular face or tungsten atom to use its two remaining stead of the four expected from the four held in common by the two octahedra is valence electrons fo>r the formation of a available bond orbitals. Also, in boron large enough to permit the two tungsten double bond with another atom of molyb carbide, B4C, which is an electron-deficient atoms to approach one another to the small denum or tungsten. The distance from structure with 3V5 electrons for every four distance 2.46 Α., a distance smaller than the metal atom to the oxygen atom sug atomic bond orbitals, each boron atom is that between tungsten atoms in metallic gests resonance of about four covalent surrounded by six atoms (either five boron tungsten. Indeed, this distance inter bonds among the six positions, causing the atoms and a carbon atom or six boron preted by the equation connecting bond total valence of the molybdenum or tung atoms), and the carbon atoms are present number and interatomic distance leads sten atom to be approximately 6. In the as ketene groups C=C=C, with, lxowever, to the value 1.70 for the tungsten-tung corresponding cr.vsta.ls molybdenite, M0S2, the end carbon atoms having throe boron sten bond number. The bond number for and tungstenite, \VS2f however, the metal neighbors apiece instead of the two that atoms are so far apart that there is no bond would be expected for the ketene bond formed between them. structure (5). Similarly the molecules of There are many essentially nonmetallic platinum tetramethyl, Pt4(CH3)ic, in which crystals known in which metal atoms ap there are electron pairs enough for quadri proach one another to within such dis valent platinum to form four single bonds, tances as to correspond to significantly whereas the platinum atom has six stable large fractional bond numbers, and there i^ d2sp3 bond orbitals, have been found by R. little doubt that many of the physical E. Rundle and J. II. Sturdivant {0 to have and optical properties of the crystals are a resonating-bond structure in which each determined essentially by this closeness of carbon atom has increased its coordination approach. For example, the oxygen com number to 5, with platinum having its pounds containing iron seem to have a normal coordination number of 6. The color which is corrclaated with the distance metals and intermetallic compounds, of between iron atoms: pseudobrookite, course, provide an extremely large number Fe2Ti05, and hematite, with iron-iron dis of examples of structures of this sort, in tance 2.88 A., arc redt whereas hydrated which bonds resonate among a number of iron oxides such as bepidocrocite, goethite, positions considerably greater than the limonite, and xnntfciosideritc tend to be number of bond orbitals available. A lighter in color. rFhe mineral cubanite, few years ago the general principle was ex CuFc^Sa, contains pairs of iron-sulfur tet- pressed to me by V. Schomaker that when rahedra in which tlie iron-iron distance, the number of electron pairs is Less than approximately 2.5 A, corresponds to a the number of available bond orbitals reso bond number of 0.3- It was suggested by
VOLUME 2 5, NO. 4 1 » «OCTOBER 13, 1947 2971 the investigator of the crystal, M J. ence of iron in both the ferrous and ferric period which forms six octahedral*d2spl Buerger (&), that this closeness of approach oxidation state. Black tourmalines also co valent bonds. of iron atoms might be related to the un usually contain both ferrous and ferric Examples of the similarity of half-full usual ferro magnet ism shown by this iron. Another intensely fc>laclc mineral, and full shells for isolated atoms or ions sulfide mineral. with black streak, is ilvaite, withi composi are not hard to find. The terpositive gado + + + ++ The theory of the color of dyes and other tion Ca(Fe )2Fe (Si04)2011- linium ion, with seven 4/electrons, is color complex organic molecules has been Molybdenum blue and tungsten blue, less, and in this and other properties (ex rather well developed in recent years, and which have intense deep blue coloration, cept paramagnetism) it resembles the the color of these substances is reasonably have the formulas M0O2.5—3 and W0O0.5-3. terpositive lutecium ion with fourteen 4/ well understood. However, little progress The tungsten bronzes also cont-ain tung electrons. The bipositive europium IOD has been made in the development of a sten in an intermediate "valeoce state;· and bipositive ytterbium ion, .which simi systematizing or correlating theory of the their formulas lie between -the limits Na2- larly have a half-full and full 4/ subshell, color of inorganic complexes. There is one W206 and Na2W309. Many met,al oxides, respectively, also have similar properties. set of substances which shows especially such as Fe304, U308, and Pr40nr may owe A striking phenomenon is the abnormally striking coloration. This is the set of sub their black color to this phenomenon. large atomic volume shown by metallic stances containing the same element in two However, it is interesting that the inter europium and metallic ytterbium, and by different valence states. Substances of mediate oxide Sb204 is white, altJhough the no other rare-earth metal. This large this sort have been recognized for many halogen complexes of antimony wit h mixed atomic volume of these two metals is due years as having abnormally deep and in valence aVe intensely colored. to their acceptance of metallic valence 2, tense coloration * For example, the com The consideration of the color and other instead of the normal value of about 3 plexes of cuprous copper with chloride properties of ordinary complexes (not in shown by the other rare-earth metals. ion, in solution in concentrated hydro volving intermediate oxiciatioxi states) The metallic valence 2 is correlated for chloric acid, are colorless, as is cuprous has recently led me to formulate a new europium with the achievement, of a half- chloride itself, and the complexes of cupric rule, to the effect that lialf-fuLl and full full 4/ subhsell and for ytterbium with the copper with chloride ion are green. How electronic shells in an atom a,xe closely achievement of a full 4/ subshell. ever, if cuprous and cupric solutions are similar in properties. This rule applies In transition elements forming six co- mixed an intensely colored brown or black not only to the ordinary shells such as the valent bonds there are three 3d orbitals solution is obtained, apparently due to 3TOgrams, etc., ultimately leading by continued con chloride complex AuCl4~ (10). The exist and for his active work in furthering densation to rings, infinite chains, and ence of these two distinct complexes rules the work of scientific societies-" sheets of silicate tetrahedra, offers no sig out the obvious suggestion that the intense A member of the AMERICAN* CHEMI nificant problems at the present time. color is due to the resonance of electrons CAL SOCIETY since 1915, Dr, Volwiler This process of condensation of simple among the atoms of the metal, in such a has played an aggressive role in fur acids to complex acids, with sharing of way as to give each atom a resonating thering the work of the SOCIEITT. He is polyhedral elements, is well understood. structure in which it is a hybrid of two currently a director-at-large and has Often, however, it is found that an element covalent states. also served as chairman oi the Division forms certain very complex polynuclear Another example of the phenomenon is of Medicinal Chemistry, chairman of anions which show a striking stability, and observed often in the chemical laboratory the Chicago Section, councilor, and clearly do not simply fit into a series of when a solution containing ferrous ion is councilor-at-large. During 1922—24, polymers of increasing complexity. One precipitated with alkali. Ferrous hydrox he edited the Chemical Bulkt-zn of the set of examples is the duodecimolybdic ide is white, and ferric hydroxide is brown. . Chicago Section. acids and the duodecitungstic acids, such as When a ferrous solution is precipitated, Born in Hamilton, Ohio», in 3L893, Dr. ordinary phosphomolybdic acid. Nearly however the initially white precipitate is v Volwiler was graduated froria Miami 20 years ago I suggested a structure for immediately partially oxidized by atmos University (Ohio) and rec&ived his these duodeci complexes in which a pheric oxygen, to form a ferrous ferric*hy Ph.D. from the University of Illinois roughly spherical cage of twelve condensed droxide, which is black in color (or deep in 1918. He joined Abbott Laborato octahedra was formed about a central green when finely divided). ries in 1920 as chief chenaist after a brief phosphate ion or similar tetrahedral ion. A few years ago it was pointed out to teaching career and in Î94S ' he was It was then shown by Keggin that these me by Sterling Hendricks that ordinary made executive vice president, having duodeci complexes do possess a structure black mica, biotite, which has an intensely been in charge of reséarçH sincœ 19.30. of this general sort, but with the twelve black color, owes this color to the pres molybdenum or tungsten octahedra ar-
2972 CH EM I CAL AND ENGINEERING NEWS ranged in a somewhat different way from the complex ion TaeClis^""*". The two re Same Great Problems that which I had proposed. I believe that maining halide ions are easily replaced by One great problem in structural chemis man}" of the surprisingly complex stable hydroxide ions or other anions. A reason try which still awaits satisfactory solution anions formed by elements such as molyb able structure for the complex is that in is that of the structure of metals and inter- denum, tungsten, vanadium, eolumbium, which the six tantalum atoms occupy the metallic compounds. A small amount of and tantalum have similar compact st ruc- six corners of a regular octahedron, with the progress has boon made in correlating the tures of condensed polyhedra. twelve halogen atoms near the centers of composition of alloys such as the gamma An example of the complications which the twelve edges of the octahedron. With alloys (Cu5>Zn8, Cu3iSii8, Al4C'u9, Fe5Zn2i, are introduced into inorganic chemistry such a structure each tantalum atom is etc.) with the Hume-Rothery ratio of va by the stability of these unusual com bonded to four halogen atoms, which lie lence electrons to atoms, and with the elec plexes ean be seen by reading about the at the corners of a square which may be tron numbers of Brillouin zones as calcu chemistry of molybdenum dichloride, nearly coplanar with the tantalum atom, lated by quantum mechanical methods. Mo('U>. When this substance is dissolved and each halogen atom is bonded to two Nevertheless, progress has not yet been in water only one third of the chlorine is tantalum atoms. There are not two un great enough to permit confident predic precipitable by silver ion. The electro shared electron pairs (four electrons) per tions to be made about intermetallic com lytic properties of the aqueous solution are tantalum atom to occupy the other two pounds, nor to provide a satisfactory gen also abnormal, and show the presence of corners of an octahedral coordination poly eral theory of their composition, structure, an ion with large electrical charge. It hedron about tantalum, but only an aver and properties. was suggested long ago that the substance age of 22/ electrons. The significance of 3 Another problem is that of the structure contains the complex Mo Cl r+. The this electron number is not clear. 3 4 of activated complexes. The general difficulties of assig ι a reasonable elec Vanadium, eolumbium, and tantalum quantum mechanical concept involving tronic structure to ti*is complex caused me form many compounds which can be rep resonating bonds, as developed by Eyring a few years ago to assume that the com resented as salts of oxygen acids contain and Polyani, is satisfying, but a general plex is Mo Cl8 + + + +, and that molybdenum 6 ing six metal atoms. An example of a theory of the structure and stability of acti dichloride itself is to be assigned the for hexavanadate is sodium hexavanadate, vated complexes still awaits formulation. mula [ Mo Cl ] + + + +C1 -. The ionic chlo 6 8 4 Na2V60i6.3H2O. A possible structure for It may turn out that the problem of the rine is easily replaced by other anions, such the hexavanadate complex ion may be as structure of atomic nuclei may be consid as bromide ion, hydroxide ion, and sulfate signed by writing this formula Na2V6- ered a problem of structural chemistry. ion. In order to verify this suggestion Oi3(OH)r>. If six vanadium atoms are I do not know to what extent the avail Philip Vaughan in our laboratories has placed at the corners of an octahedron able facts about the properties of nuclei been making an x-ray investigation of and twelve oxygen atoms are placed out indicate that the structure is a dynamic two crystals thought to contain this com from the centers of the twelve edges of the one, in which the nucléons cannot be as plex, (NH ) IM06Cl8]Cl6.2H O and H - 4 2 2 2 octahedron, a thirteenth oxygen atom signed average positions relative to one lMo Cls]Cl6.6H 0. In the meantime, 6 2 may then be located at the center of the another. It seems to me, however, that it however, crystal structure determinations octahedron, being thus bonded to all is conceivable that the forces between nu of two other substances, [Mo Cl ](OH) .- 6 8 4 six vanadium atoms, and six hydroxyl cléons involve attractive terms and repul 14II 0 and [ Mo Cl 3 C1 .8H 0, have been 2 e 8 4 2 groups may be placed directly out from sive terms in such a way as to cause the reported by Cyrili Brosset {11). These the six vanadium atoms, completing nucléons to assume average equilibrium crystals have been found to contain com the six octahedra. Hexacolumbates and positions relative to one another in the plexes with the expected structure. This hexatantalates also occur with similar same way that atoms do in molecules and structure is a very interesting one. The formulas, such as K2Cb6Oio(OH)6.2H20, crystals, and that in the course of time the eight chlorine atoms are at the corners of a Na2Ta6O,3(0H)6.2H2O, and (NH4)2Ta6- geometrical structures of atomic nuclei cube, and the six molybdenum atoms are a 013(OH)6.2H20. Most of the salts of these may be determined. A great contribution little displaced outward from the centers of acids, however, have formulas correspond toward the solution could be made by ob the six faces of the cube. Presumably each ing to the replacement of eight hydrogen taining diffraction data from atomic nu molybdenum atom forms bonds with the atoms. Examples are KsObOi&.ieHsO, clei (starting with the deuteron, tritium four chlorine atoms which surround it in Na2K6CbOl9.9H20, Na8Ta60,9.24H20, K8- nucleus, and alpha particle) by bombard a square, nearly coplanar configuration, Ta6019.16H20, Ag8Ta6019.3H2O, and Mg4- ing them with essentially monochromatic each chlorine atom thus being bonded to Ta6Oi9.9H2(). It seems likely that the neutrons of high energy, approximately three molybdenum atoms. Inasmuch as htxacolumbate and hexaiantalate ions in 30,000,000 electron volts. bivalent molybdenum has two unshared these crystals have the structure described electron pairs, the configuration suggests above, with the hydrogen ions of the six In the field of organic and biological that the molybdenum atoms in this com hydroxyl groups replaced by metal. chemistry, it is my opinion that the struc ture of proteins and the origin of the spe plex have an octahedral configuration with Another structural problem of somewhat the unshared pairs at two opposite corners cific properties of biological substances are different sort is that presented by the com the most important problems at the pres of the octahedron, one directed toward the plex ion Pbg , which exists in liquid center of the complex and one directed out ent time. The specificity of antigens and ammonia solutions containing sodium and antibodies, of enzymes, and of genes will, ward. This arrangement accordingly con lead, as was shown by C. A. Kraus. A forms to the general rule that an atom with I think, all be found to be due to the *ame possible structure for this complex is again modes of phjrsical-chemieal interaction some unshared pairs of electrons tends to a cubic structure, with eight lead atoms at form a coordination polyhedron, with between molecules. The evidence from the corners of the cube and one in the cen the field of immunochemistiy supports some corners occupied by bonded atoms ter of the cube. The lead atoms at the and others by unshared pairs. very strongly the concept that this biologi corners of the cube might be considered to cal specificity is due to a complementari- I think that the compound TaeBru, be uninegative, analogous to bismuth, ness in structure of large molecules, and studied by W. H. Chapin, may be some and with the power of forming three co- that the specific forces operate only when what similar in structure. This substance, valent bonds, extending along edges of the the complementary structures are in close in which tantalum has an average oxidation cube. A quadripositive lead atom at the contact with one another, with the surface l number of 2 /z (the color of the compound center of the cube would then cause the atoms of the two structures approaching to is deep green, corresponding to the in resultant charge on the complex to be cor within an Angstrom or a few Angstroms termediate oxidation state), contains the rect. There would, of course, be bonds before the forces become large. It is true ++ complex ion TaeBri2 , and the related formed between the central lead atom and emerald-green substance Ta6Cln contains the surrounding atoms. (Continued on page SO/fi}
VOLUME 2 5, NO. 4 1 » -OCTOBER 13, 1947 2973 CONSULTANTS .. CHEMICAL CONSULTANTS, ENGINEERING SERVICES, TESTING LABORATORIES, PATENT ATTORNEYS, ETC.
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Applied Mathematics Mathematics Laboratories, the Office of Laboratories Established Naval Research, the Bureau of the Census, S itriicXural Chemistry and other government agencies. At pres {^Jontijriued jrom page 2973) A federal center of applied mathematics*, ent it is setting up the mathematical t,he National Applied Mathematics Labo specifications for two high-speed electronic ratories, has been established as a division computers being constructed through the that tints theo>ry may seem to be incom of the National Bureau of Standards. Bureau of Standards for the Office of patible wit h tlie work of A. Rothen {12), Organized to conduct research and provide Naval Research and the Bureau of the who has published experimental results in services in the field of applied mathe Census at a cost of $300,000 each. This terpreted assfakowing that under certain cir- matics, the organization is oriented around organization is responsible for the coordi eumstanLces enzymes are able to exert then modern mathematical statistics as applied nation of mathematicians, electronics engi specific actiora through a film of polymer r,o the physical and engineering sciences neers, and physicists who must cooperate as much* as 2O0 A. thick. I do not have and to the development and use of modern to produce this revolutionary equipment. any exp-lanatÊ-on to offer for these experi high speed computing. The Applied When completed one of the machines will ments except the obvious one that th*· Mathematics Laboratories include four be installed at the Institute of Numerical polvmei- film may not be completely intact separate laboratories: * the Institute of analysis. and impenetrable, but I feel that the evi Numorica Analysis, the Computation dence for the theory that specific biological Laboratory, the Statistical Engineering Directory of forces result from complementariness ID Laboratory, and the Machine Develop Ceramic Laboratories stri_icUir-e and require very close approxi ment Laboratory. mation of the complementary' structures foi Xhe work is carried on with the advice A revision is being made of Bureau υ l theâr ooeration is extremely strong, and 1 and guidance of a committee called the Alines Information Circular 6999R, which think it highhv likely that this is the only Applied Mathematics Council, made up lists commercial laboratories engaged in mechanism oif biological specificity which of representatives of government agencies the analysis and testing of ceramic and has beesn developed in living organisms. and private organizations actively inter mineral products. Directors of labora The jprogre^ss of science in recent year*· ested in the work of the unit. tories whose work falls in this category, is bringing "biology and medicine intc The Institute of Numerical Analysis, on and who have not recently received a closer at-nd closer contact with the bash· the campus of the University of California questionnaire on this subject from the sciences?-, and I am confident that the nexi at Los Angeles, is being underwritten for bureau, are -asked to communicate with ΐο\\τ dec^ades ^vill bring to us a detailed un r,he next two years by the Office of Naval Morris Slavin, U. S. Bureau of Mines, derstanding o>f the molecular structure oi Research. Its primary function is to con College Park, Md., so that their labora biodogicral systems, and that this under duct research and training in the types of tories may be included in the new list. standing will, help in the rapid genera) mathematics which are pertinent to the progress of bmology and medicine. efficient exploitation and development of Mellon Institute high-speed automatic digital computing Rerferemices A brochure entitled ''Postwar Research machinery. in Mellon Institute" is the thirty-fourth (1) J. -Am. Cham. Soc, 65, 179 (1943). Xhe Computation Laborator}', also annual report of the director, E. R. Weid- (fc) flwE-r. Standards J. Res., 18, 629 (1937, (5) G. S. Zheianovand N. G. Sevast'yanov underwritten by the Office of Naval Re lein, to the board of trustees. Published search, includes the mathematical tables *Oompt- rend. acad. sci. U.R.S.S., 32 in condensed form in C&EN, May 10, <=£32 (1S41) (in English) ; project of the Bureau of Standards. The 1947, the full report is 38 pages in length. II. K. CTark and J. L. Hoard, J. Am unit is providing a general computing serv Copies can be obtained from Mellon Insti *Chem. Soc.,65, 2115 (1943). (4r) J. Am.Chem.Soc.,69, 1561 (1947). ice of high quality and large capacity for tute of Industrial Research, Pittsburgh private industry, government agencies, (S) Ar-M. Ke^n. Mineral. Geol., 12A, Nr. 4 13, Pa. <1935) . educational and research institutions. (S) J. Chem- Soc, 1939, 286. Xhe Statistical Engineering Laboratory (T) Ar-k. Ke-3n. Mineral. Geol., 24A, Nr. ίί provides a general consulting service on Venture Capital <1946) . methods of modern statistical inference as A brief description of the services and (S) J. Am. Chem. Soc, 67, 2056 (1945) (9) J. Chem. Phys., 2, 29S (1934); applied to the engineering and physical organization of a company incorporated K_ A. Jensen, Ζ. anorg. allgem. Chem., sciences. in 1946 for the purpose of making venture 252,3 17 (1944). The Machine Development Laboratory capital more readily available for develop (ΙΟ) N_ Elliott andL. Pauling, J. Am. Chem. is in charge-of the development and con ment of untried business enterprises of a JSoc, SO, 1846 (1938). (11) Ar-kiv. Klem. Mineral. Geol., 20A, Nr. 7 struction of computing machines which scientific nature is contained in a pamphlet <1945> ; Ibid., 22A, Nr. 11 (1946). will meet performance specifications estab published by New Enterprises, Inc., 84 (12) J. Biol Chem., 163, 345 (1946); Ibid., lished by the operating units of the Applied State St., Boston 9, Mass. 167, 2S9 (1947} ; Ibid., 168, 75 (1947).
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