POPE, WILLIAM JACKSON

(b. London, England, 31 October 1870; d. Cambridge, England, 17 October 1939), organic chemistry.

Pope’s parents, William Pope and Alice Hall, were staunch and active Wesleyans who had eight children, of whom William was the eldest. In 1878 he entered the Central Foundation School, in London, where his ability to learn rapidly gave him leisure at the age of twelve to carry out simple chemical experiments in his bedroom. While at school he also developed great skill as a photographer—many of his early photographs were in perfect condition fifty years later. Pope readily learned foreign languages and became proficient in French and German in his teens and in Italian somewhat later. He was known, on the eve of his departure to deliver an important lecture in Paris, to sit down at his typewriter, think deeply for a few minutes, and then rapidly type the complete lecture in French . This ready acquisition of foreign languages was not limited to Pope; his brother Thomas translated into English E. Molinari’s Treatise on General and Industrial Organic Chemistry (2nd ed., 1921–1923).

Pope left school in 1885 with full marks on his final examinations in theoretical and practical chemistry and in theory of music, and obtained entrance scholarships to Finsbury Technical College and the City and Guilds of London Institute, South Kensington. At the latter he worked under H. E. Armstrong. A firm believer in the heuristic method of teaching, Armstrong forbade his students to take any examinations, so they ultimately departed without degrees. In 1897 Pope became head of the chemical department of the Institute of the Goldsmiths’ Company at New Cross.

In 1901 Pope became head of the chemical department of the Municipal School of Technology and professor of chemistry at Manchester, and in 1908 he was appointed professor of chemistry at the University of Cambridge, a post he held until his death. At the time of his election, only the major departments were headed by a professor; and the appointment of Pope at the age of thirty-eight caused some surprise in nonchemical circles.

In the following years Pope’s advancement of chemistry in various directions was recognized by the conferment of the freedom and livery of the Goldsmiths’ Company by special grant in 1919, and he served as prime warden for 1928–1929.

During World War I, Pope was a consultant to the Board of Invention and Research; and his work, particularly on the manufacture of photographic sensitizers and of mustard gas, was recognized after the war by the award of a knighthood of the Order of the British Empire.

During 1922–1936 Pope presided at the chemical conferences of the Solvay Foundation in Brussels, and he worked for several years to promote the formation of the International Union of Pure and Applied Chemistry, of which he became the first president. He was president of the Chemical Society for 1918 and 1919 and received its Longstaff Medal in 1903 and the Davy Medal of the Royal Society in 1914.

Pope’s first investigation, in collaboration with H. E. Armstrong, was an attempt to obtain a crystalline derivative of pinene. Following some very old work of Ascanio Sobrero, they exposed the terpene fraction of oil of turpentine to moist oxygen in sunlight. The solid deposit, which when purified had the composition C₁₀H₁₈O₂, was called sobrerol.¹ This compound was optically active; and the dextro and levo forms were isolated from turpentines of various origins and were studied in detail. For this purpose Pope’s knowledge of crystallography and his skill with the goniometer were of great assistance to Armstrong.

Pope was then joined by F. S. Kipping, with whom he worked for several years. They showed that camphor was sulfonated by fuming sulfuric acid and by chlorosulfonic acid, which gave the corresponding sulfochlorides, compounds of exceptional crystallizing power. Furthermore, these sulfochlorides and sulfobromides lost sulfur dioxide when heated, forming the corresponding halogenocamphors, which they termed π-derivatives because of their pyrogenic formation.² Furthermore, Kipping showed that the sulfonation had occurred on one of the gem-dimelhyl groups and (on the basis of J. Bredt’s camphor formula) on the 8-mcthyl group—that is. on the methyl group furthest from the carbonyl group. Consequently the acid known as α-bromo-π-camphorsulfonic acid (Formula 1) should be termed 3-bromccamphor-8-sulfonic acid.³

A further investigation produced several new halogenocamphors. The study of these compounds, their sulfonic acids, and the conditions of their racemization revealed a number of points of crystallographic and theoretical interest and of the particular relationships that Kipping and Pope termed pseudoracemism.⁴

Pope and Kipping also investigated the crystallization of sodium chlorate from aqueous solution, whereby dextro (d) and levo (l) crystals are deposited in virtually equal quantities. The activity here must be due to the arrangement of the molecules in the crystal, since the molecule is symmetric. Each crystal, when dissolved in water, therefore gives an inactive solution. In an asymmetric environment, such as an aqueous solution of glucose, the weights of the deposited dextro and levo crystals of the chlorate are no longer equal. The investigation of this subject and later of the similar behavior of ammonium sodium tartrate in considerable detail was greatly aided by Pope’s crystallographic skill.⁵ This fruitful partnership ended when Kipping became professor of chemistry at University College, Nottingham, and Pope became head of the chemical department of the Goldsmiths’ Institute at New Cross.

At the Goldsmiths’ Institute, Pope and S. J. Peachey investigated “tetrahydropapaverine,“which hitherto had resisted optical resolution. Pope recalled his earlier experience with bromocamphorsulfonic acid; and with the salt of this acid he readily resolved the base, which was later found by F. L. Pyman to be dihydropapaverine.⁶ This was one of the earliest resolutions using bromocamphorsulfonic acid, and a number of resolutions of basic compounds or dissymmetric cations using salts of camphorsulfonic and bromocamphorsulfonic acids followed. These acids were of outstanding value at this stage of stereochemical elucidation.

Pope then started a new line of investigation, which was conspicuously successful and ipwjensely increased his reputation. Compounds that showed optical activity in solution had hitherto all contained one or more asymmetric carbon atoms. Le Bel had claimed that by growing microorganisms in an aqueous solution of meiliylethylpropylisobutylam-moniurfl chloride (see Formula 2a). he obtained that salt in an optically active condition.⁷ This work was carefully repeated by W. Marckwald and A. von Droste-Huelshoff, who were unable to confirm his results.⁸ E. Wedekind similarly failed to resolve benzylphcnyldllylmethyUmmonium iodide (Formula 2b).⁹

Pope and J. Read, after a very carefully controlled repetition of Le Bel’s work, decided that he had never obtained the chloride.¹⁰ They then prepared Wedekind’ iodide, converted it into the d-camphor-sulfonate, and by fractional crystallization obtained the diasteroisomerides, from which they isolated the opticallyactive iodides and bromides. This proved “that quaternary ammonium derivations in which the five substituting grouos are different, contain an asymmetric nitrogen atom which gives rise tp antipodal relationships of the same kind as those correlated with an asymmetric carbon atom.”¹¹ The chemicl and optical properties of Wedekind’s iodide and salts with anions were examined in considerable detail.¹²

This type of work was extended by combining ethyl methyl sulfide with ethyl bromoacetate to yield methylethylthetin bromide (Formula 3a), which was converted into the d-bromocamphorsulfonate; recrystallization similarly gave the d-and l-forms

of methylethylthetine bromide.¹³ The analogous phenylmethylselenetine bromide (Formula 3b) was similarly resolved into optically active forms, again via the d-bromocamphorsulfonatei.¹⁴ The appalling and persistent stench of selenides of type R₂Se very seriously delayed this work.

Compounds of tin were next investigated. These compounds required careful manipulation, because they were highly toxic in both the liquid and the vapor states. Pope and Peachey were able, however, to prepare methyl ethyl propyltin iodide (Formula 4a).¹⁵ This liquid was volatile without decomposition and was soluble in nonpolar solvents; thus it was a

covalent compound. It reacted with silver d-camphorsulfonate to give the corresponding sulfonate (Formula 4b), which was soluble in water and was clearly a salt. Evaporation of an aqueous solution of the sulfonate gave solely the d-tin d-sulfonate (Formula 4b), indicating a ready racemization of the cation of the salt and a marked difference in the solubilities of the two diastereisomerides. Treatment of the active sulfonate in aqueous solution with potassium iodide precipitated the active iodide, which readily underwent recemization.

The iodide was clearly of a type different from the well-recognized quaternary ammonium and the sulfonium and selenonium salts. It has been suggested that the sulfonate may have formed a tetrahedral cation (Formula 5a) that readily gave the tetrahedral covalent iodide (Formula 5b).

In a brief excursion into true organometallic chemistry, Pope and Peachey showed that methyl-magnesium iodide reacted with platinum tetrachloride to give compounds of type (CH₃)₃ PtX, where X is OH, CI, I, or NO₃.¹⁶

Similarly, Pope and C. S. Gibson found that ethylmagnesium bromide reacted with auric tribromide to give two compounds considered to be (C₂H₅)₂AuBr and (C₂H₅)₂AuBr¹⁷ Many years later Gibson and his collaborators reinvestigated these gold compounds and found that they were both dimeric bridged compounds of structures shown in Formulas 6a and 6b, respectively.

In 1906–1910 Pope devoted a great amount of time to attempting, with W. Barlow, to correlate chemical constitution and crystal structure. The “valency-volume theory of crystal structure,” which they developed, states, in brief, that the space that an atom occupies in a crystal is proportional to its valency.¹⁸ The labors of Barlow and Pope revealed many factors that have helped the evolution of modern crystallography, but the main theory has been discarded.

While in Manchester, Pope initiated an outstanding investigation, which was completed at

Cambridge. It was reasonably certain that an allene hydrocarbon carrying substituents as in Formula 7a would have pairs of bonds alternately in the horizontal plane (thick lines) and in a vertical plane running through the central carbon atoms (thin lines). This compound would possess molecular dissymmetry and should be resolvable into optically active forms. However, attempts by various chemists to synthesize such a compound, with a and/or b carrying acidic or basic groups for resolution purposes, had failed. (The realization of this synthesis and resolution did not occur until 1935.¹⁹

Pope, in collaboration with W. H. Perkin, Jr., therefore attempted to synthesize l-methylcyclohexylidene-4-acetic acid (Formula 7b), a compound similar to the allene hydrocarbon (Formula 7a) but with one double bond of the latter expanded to a six-member ring. This synthesis was achieved, but by a laborious method giving a low overall yield.²⁰ By coincidence. W. Marckwald and R. Meth had been investigating the synthesis of the acid (Formula b);²¹ their product, certainly different from Perkin and Pope’s acid, was later identified as the isomeric acid (Formula 7c). Shortly afterward O. Wallach devised a greatly improved synthesis of the true acid (Formula 7b) and, without divulging the method, offered to supply Perkin and Pope with sufficient acid for the resolution if his name was subsequently included in the published results. The resolution was finally accomplished using the brucine salt and the active acid isolated had [α]_D ± 81°. By a very exceptional arrangement, the paper was published simultaneously in English and in German.²²

Another gap in the stereochemistry of carbon was subsequently filled. Before 1914 no one had synthesized and resolved a compound having only one carbon atom, which must necessarily be asymmetric. After considerable work Pope and J. Read synthesized chloroiodomethane sulfonic acid (Formula 8a) and resolved it, using initially hydroxyhydrindamine (Formula 8b) and later brucine for this purpose.²³ The acid had [M]₅₄₆₁ + 43° and considerable optical stability: its aqueous solution could be boiled for two hours without loss of activity.

At the outbreak of World War I, Pope was in Australia presiding over Section B (chemistry) of the British Association for the Advancement of Science. He immediately returned to England and was soon involved in chemical problems, one of which was the preparation of photographic sensitizers. Photographic plates at that time were prepared with a silver bromide-silver iodide emulsion, which was sensitive only in the ultraviolet, violet, and blue regions; aerial photographs taken at dawn in a predominantly red light were almost useless. The enemy had plates on which the emulsion was incorporated with a sensitizer extending the sensitivity well into the red region. Pope, with much help from W. H. Mills and a small group of research students, elucidated the structure and the preparation of the main sensitizer, Pinacyanol, and of many other such compounds, and clarified their chemistry. Pope and Mills, writing in 1920 about these sensitizers, stated: “. . . we commenced the study of the more necessary of these [latter] substances and devised methods for their preparation on a sufficiently ample scale. Throughout the war practically all the sensitizing dyestuffs used by the Allies in the manufacture of panchromatic plates were produced in this [the Cambridge] Laboratory.”²⁴

A second main project, carried out with C. S. Gibson, was the preparation of mustard gas, or 2, 2’-dichlorodiethyl sulfide. This was prepared by the interaction of ethylene and sulfur chloride:

This method apparently was quicker than the German method.²⁵ In the latter ethylene chlorohydrin ([HOCH₂CH₂CI) was converted into 2,2′-dihydroxydiethyl sulfide ([HOCH₂CH₂]S), which, when treated with hydrogen chloride, gave the required product. The large-scale preparation of ethylene chlorohydrin was apparently the slow stage that restricted the output.

The chemistry of mustard gas was later investigated in considerable detail, as was that of the β-chlorovinylarsines.²⁶ In the course of this work, the action of “Chloramine-T,” or p-toluenesulfonchlorosodioamide (CH₃C₆H₄SO₂NN_aCI), on many other sulfides to give compounds of type CH₃C₆H₄SO₂N ← SR₂ was examined.²⁷ These compounds, named sulfilimines and later sulfonilimines, could be resolved into optically active forms if the sulfur atom carried two unlike groups; hence a coordinate link joined the S and N atoms.

Two main lines of research occupied Pope for several years: the metallic coordination compounds formed by aliphatic polyamines and the stereochemistry of certain spirocyclic compounds. Much earlier A. Werner had used ethylenediamine (Formula 9a) to coordinate with various metallic halides and had obtained some noteworthy examples of isomeric compounds, several of which were

resolved into optically active forms. Pope and Mann considered that 1, 2, 3-triaminopropane (Formula 9b) might offer an even wider field.

This triamine was synthesized in good yield and was found to give very stable octahedral complexes of type [trp₂M]X₃, where M = Co(III), Rh (III), and [trp₂M]X₂, where M = Ni (II), Cd (II), Zn(II), and “trp“indicates one molecule of the triamine; no examples of isomerism were, however, detected.²⁸ The stability of these complexes is well shown by [trp₂Zn]I₂ and [trp₂Pt(II)]I₂, which crystallize unchanged after their aqueous solutions have been boiled for one to two hours.

Chloroplatinic acid (H₂PtCl₆), however, reacted in boiling aqueous solution with the triamine to give a crystalline compound of composition trpPtCl₄HCI, in which only two amino groups had coordinated, the third forming a hydrochloride salt. This could occur in either the 1,2-diamino complex (Formula 10a) and the 1,3-diamino complex (Formula 10b). The compound was resolved as the d-camphorsulfonate into optically active forms and was therefore the 1,2-diamino form, which has an asymmetric carbon atom. This was the first example of a carbon atom becoming asymmetric by the operation of a coordinate link.²⁹

ββ′β″-triaminotriethylamine (H₂NCH₂CH₂)₃N, “tren,” was found to coordinate as a tetramine; and with Ni (II) salts it gave two types of complexes, such as [Nitren]SO₄ and [Ni₂tren₃]I₄. The sulfate was shown to be monomolecular, and consideration of strain factors indicates that the nickel atom must have the tetrahedral configuration. Similar considerations apply to the compound PttrenI₂.³⁰ γγ′γ″-triaminotripropylamine ([H₂NCH₂CH₂CH₂]₃]N) gave similar compounds, such as

([H₂NCH₂CH₂]₃NNi)(SCN)₂.³¹

The work on complex metallic compounds initiated by Mann and Pope continued long after Pope’s death and in 1934 led to the first systematic use of tertiary phosphines and arsines, thus opening a very wide and important field of coordination chemistry.³² Two centroasymmetric spirocyclo compounds attracted Pope’s interest. Spiro-5,5-dihydantoin (Formula 11a), a known compound, is a member of this class; and

Pope considered that the possibilities of tautomeric shift—to the structure of Formula llb or 11c—would make the compound sufficiently acidic for stable salt formation with bases. The resolution was readily accomplished, for a hot ethanolic solution of the dibrucine salt deposited the l-form as the monobrucine salt, and the mother liquor slowly deposited the d-form as the dibrucine salt. The stereochemical and crystallographic relationships were examined in detail.³³

A simpler compound of this class was 2,6-diaminospiro [3.3] heptane (Formula 12), which S. E. Janson

and Pope were able to prepare from the corresponding 2,6-dicarboxylic acid.³⁴ It was resolved as the di-d-camphor-β-sulfonate and converted into the dihydro-chloride, having [M]₄₃₅₈ α 30° in aqueous solution. This diamine, by virtue of its simplicity and its rigid rings, was admirably suitable for the application of mathematical Théories of optical rotatory power and chemical constitution; and it was utilized for this purpose by M. Born.³⁵

NOTES

1. “Terpenes and Allied Compounds. Sobrerol . . .” (1891).

2. “Studies of the Terpenes and Allied Compounds; the Sulphonic Derivatives of Camphor” (1893, 1895).

3. F. S. Kipping, “Derivatives of Camphoric Acid,” in Journal of the Chemical Society, 69 (1896), 913–971.

4. Kipping and Pope, “Optical Inversion of Camphor”(1897) and “Racemism and Pseudo-Racemism” (1897).

5. Kipping and Pope, “Enantiomorphism”(1898) and ldquo;The Crystallisation of Externally Compensated Mixtures”(1909).

6. Pope and S. J. Peachey, “The Resolution of Tetrahydro-Papaverine Into Its Optically Active Components. . .”(1898) and “The Non-resolution of Racemic Tetrahydro-Papverine by Tartaric Acid”(1898); F.L. Pyman, “Isoquiniline Derivatives. Part 2,” in Journal of the Chemical Society, 95 (1909), 1610–1623.

7. J. A. Le Bel, “Sur La dyssymétrie et la crÉation du pouvoir rotatorie, dans les dérivés alcooliques du chlorure d’ammonium,” incomptes rendus . . . de l’Académie des sciences, 112 (1891), 724–726.

8. W. Marckwald and A. von Droste-Huelshoff, “Ueber die Methyl-äthyl-propyl-isobutyl-ammoniumbase,” in Berichte der Deutschem Chemischen Gesellschaft, 32 (1899), 560–564.

9. E. Wedekind, “Ueber das fünfwerthige asymmetrische stickstoffatom,” ibid., 517–529.

10. Pope and J. Read, “Asymmetric Quinquevalent Nitrogen Compounds of Simple Molecular Constitution” (1912).

11. Pope and Peachey, “Asymmetric Optically Active Nitrogen Compounds; d- and l-benzylphenyallymetghylammonium iodides and bromides” (1899).

12. Pope and A. W. Harvey, “Optically Active Nitrogen Compounds and Their Bearing on the Valency of Nitrogen . . .” (1901).

13. Pope and Peachey, “Asymmetric Optically Active Sulphur Compounds . . .”(1900).

14. Pope and A. Neville, “Asymmetric Optically Active Selenium Compounds and the Sexavalency of Selenium and Sulphur . . .” (1902).

15. Pope and Peachey, “Asymmetric Optically Active Tin Compounds . . .”(1900) and “The Racemisation of Optically Active Tin Compounds” (1900).

16. Pope and Peachey, “The Alkyl Compounds of Platinum”(1909).

17. Pope and C.S. Gibson, “The Alkyl Compounds of Gold”(1907).

18. W. Barlow and Pope “A Development of the Atomic Theory . . .”(1906); “The Relation Between the Crystalline Form . . .”(1907); “On Polymorphism . . .”(1908); “The Relation Between the Crystal Structure . . .”(1910).

19. P. Maitland and W. H. Mills, “Experimental Demonstration of the Allene Asymmetry,” in Nature, 135 (1935),994; and “Resolution of an Allene Hydrocarbon Into Antipodes by Asymmetric Catalysis,” in Journal of the Chemical Society(1936), 987–998. See also “Mills, W. H.,” in Dictionary of Scientific Biography, IX, 402–404.

20. W. H. Perkin, Jr., and Pope, “Experiments on the Synthesis of 1-Methylcyclohexylidene-4-Acetic Acid” (1908).

21. W. Markwald and R. Meth, “Ueber optisch-active verbindungen, die rein asymmetrisches Atom enthalten,” in Berichte der Deutschen chemischen Gesellschaft, 39 (1906), 1171–1177; and “Ueber die 1-Methylcyclohexyliden-4-essigsäure,” ibid., 2404–2405.

22. Perkin, pope and O. Wallach (1909) also in Justus Liebigs Annalen der Chemie, 371 (1909), 180–200. For later work on this acid, see Perkin and Pope, “Optically Active Derivatives of 1-Methylcyclohexylidene-4-Acetic Acid,” in journal of the Chemical Society, 99 (1911), 1510–1529.

23. pope and Read, “The Optical Activity of Compounds of Simple Molecular Constitution . . .”(1914).

24. W. H. Mills and Pope, “Studies on Photographic Sensitisers . . .” 2 pts. (1920). For further details see F. G. Mann, “William Hobson Mills,” in Biographical Memoirs of Fellows of the Royal Society, 6 (1960),201–225.

25. Pope, Gibson, and H. F. Thuillier, British patent 142875 (1918); Gibson and Pope, β,β′-Dichlorodiethyl sulphide”(1920).

26. F. G. Mann, Pope, and R. H. Vernon,“The Interaction of Ethylene and sulphur Monochloride” (1921); Mann and Pope, “The β-Chlorovinylarsines” (1922).

27. Mann and Pope, “The Sulphilimines . . .”(1922).

28. Mann and Pope, “1:2:3-Triaminopropane and Its Complex Metallic Compounds” (1925) and “The Configuration of the Bistriaminopropane Metallic Complexes” (1926).

29. Mann and Pope, “A Novel Type of Optically Active Complex Metallic Salt,” in Nature, 119 (1927), 351; Mann, “Tetrachloro Platinum. an Optically Active Complex Salt,“Journal of the Chemical Society(1927), 1224–1232.

30. Mann and Pope. “ββ′β″-Triaminotriethylamine and Its Complex Metallic Compounds” (1925); “The complex Salts of ββ′β″-Triaminotripropylamine with Nickel and Palladium”(1926).

31. Mann and Pope, γγ′γ″-Triaminotripropylamine and Its Complex Compounds With Nickel”(1926).

32. See Mann, “The Development of Co-ordination Chemistry at the University of Cambridge, 1925–1965,” Advances in Chemistry series, no. 62 (washington, D.C., 1966), 120–146. See also Mann and D. Purdie, “The Constitution of Complex Metallic Salts. Part 3,” in Journal of the Chemical Society (1935), 1549–1563; (1936), 873–890.

33. Pope and J. B. Whitworth, “Optically Active Di- and Tetramethylspiro-5:5-Dihydantoins”(1936).

34. S. E Janson and Pope, “Optically Active Amines Containing No Asymmetric Atom,” in Chemistry and Industry (1932), 316.

35. M. Born, “On the Theory of Optical Activity,” in Proceedings of the Royal Society, 150A (1953), 84–105.

BIBLIOGRAPHY

Pope wrote the following articles while at the City and Guilds of London Institute (1891–1897): “Terpenes and Allied Compounds. Sobrerol, a Product of the Oxidation of Terebenthene (Oil of Turpentine) in Sunlight,” in Journal of the Chemical Society, 59 (1891), 315, written with H.E. Armstrong; “The Crystalline Forms of the Sodium Salts of the Substituted Anilic Acids” ibid., 61 (1892), 581;“θ-Benzoic sulphinide,” ibed., 67 (1895), 985; “The Crystalline Form of the Isomeric Dimethyl-pimelic Acids” in Proceedings of the Chemical Society, 11 1895), 8 ; “Substances Exhibiting Circular Polarisation Both in the Amorphous and Crystalline States,” in Journal of the Chemical Society, 69 (1869), 971; “The Refraction Constants of Crystalline Salts,” ibid., P. 1530; “A Compound of Camphoric Acid With Acetone,” ibid., p. 1969; “A Method of Studying Polymorphism, and on Polymorphism as the Cause of Some Thermochemical Peculiarities of Chloral Hydrate,” inProceedings of the Chemical Society, 12 (1896),142, 249; and in Journal of the Chemical Society,75 (1899), 455; “The Localisation of Deliquescence in Chloral Hydrate Crystals,” in Proceedings of the Chemical Society, 12 (1896), 249; “Enantiomorphism,“ibid., 249–251, written with F.S. Kipping; and “Crystalline Form of lodoform,” ibid., 14 (1898), 219; and in Journal of the Chemical Society, 75 (1899), 46.

while head of the Chemical department of the Institute of the Goldsmiths’ Company at New Cross, London, Pope published (1897–1901) “A Composite Sodium Chlorate Crystal in Which the Twin Law Is Not Followed,” in Journal of the Chemical Society, 74(1898), 949; “The Application of Powerful Optically Active Acids to the Resolution of Externally Compensated Basic Substances: Resolution of Racemic Camphoroxime,7” ibid., 75 (1899), 1105; “d-ac-Tetrahydro-β-naphthylamne7” in proceedings of the Chemical Societry15 (1899), 170; “Homogeneity of dl-α-phenethylamine d-camphor-sulphonate,” in Journal of the Chemical Society75 (1899), 1110, written with A. W. Harvey; “Racemisation Occurring During the Formation of Benzylidene, Benzoual, and Acetyl Derivatives of d-ac-tetrahydro-β-naphthylamine,” in Proceedings of the Chemical Society16 (1900), 74, written with A.W. Harvey; “The Inversion of the Optically Active ac-tetrahydro-β-naphylamines Prepared by the Aid of d-and l-bromocanmphousulphonioca. (1900), 206, written with A.W. Harvey; and in Journal of the Chemical Society79 (1901), 74; “Optically Active Nitrogen Compounds and Their Bearing on the Valency of Nitrogen.d-and l-alfa-Benzyl-pheenyallylmethylammonium salts,” ibid., p. 828, written with A. W. Harvey; “The Characterisation of “Racemic” Liquids” ibid., 75 (1899), 1119, written with F.S. Kipping; and “Method of Discriminating Between ‘Non-racemic‘ and “Racemic” ibid., p. 1111, written with S. J. Peachey.

While working at the Municipal School of Technology and at Victoria University of Manchester (1901–1908), Pope published “Asymmetric Optically Active Selenium Compounds and the Sexavalency of Selenium and Sulpur. d-and l-Phenylmethylselenetine salts,” in Journal of the Chemical Society81 (1902), 1552, written with A. Neville. Works written with S. J. Peachey include “The Resolution of Tetrahydropapaverine Into Its Optically Active Components; Constitution of Papaverine,” ibid., 73 (1898), 893; “The Non-resolution of Racemic Tetrahydropapaverine by Tartaric Acid7“ibid ., p . 902; “The Application of Powerful Optically Active Acids to the Resolution of Externally Compensated Basic Substances: Resolution Tetrahydroquinaldine,“ibid., 75 (1899), 1066; “Asymmertric optically Active Nitrogen Compounds; d-and l-benzylphenylallymethylammonum Iodides and Bromides,” ibid., p. 1127; “Asymmetric Optically Active Sulphur Compounds; d-methylethylthetine Platinichloride” ibid., 77 (1900), 1072; “Asymmetric Optically Active Tin Compounds: d-methelthyl-n-propyltin Iodide” in Proceeding of the Chemical Society16 (1900), 42; “The Racemisation of Optically Active Tin Compounds: d-methypropyl Tin d-bromocamphorsulphonate” ibid. (1900), 116; “Preparation of the Tetra alkyl Dervatives of Stanni-methance” ibid., 19 (1903), 290; “A New Class of Organo-tin Compounds Containng Halogens” in Proceedings of the Royal Society72A , no. 7 (1903); and “A New Class of Organo-metallic Compounds; Preliminary Notice: Trimethylplatinimethyl Hydroxide and Its Salts,” in Proceeding of the Chemical Society23 (1907), 86.See also “The Application of Powerful Optically Active Acids to the Resolution of Externally Compensated Basic Substances; Resolution of Tetrahydro-p-toluuinaldine,” inJournal of the Chemical Society75 (1899), 1093, written with E. M. Rich; and the following works written with F. S. Kipping: “Genesis of New Derivatives of Camphor Containing Halogens by the Action of Heat on Sulphonic Chlorides,” in Proceedings of the Chemical Society,9 (1893), 130; (1894), 212; “Studies of the Terpenes and Allied Compounds; the Sulphonic Derivatives of Camphor” in Journal of the Chemical Society63 (1893), 548; 67 (1895), 354; and in Proceedings of the Cheimical Society10 (1894), 163, 211; “Dextrorotatory Camphorsulphonic Chloride,” ibid., (1894), 164; “π-Halogen Derivatives of Camphor” in Journal of the Chemical Society67 (1895), 371; “The Melting Points of Racemic Modifications and of Optically Active Isomerides” in Proceedings of the Chemical Society11 (1895), 39 ; “π-Chlorocamphoric acid,“ibid., 11 (1985), 213; “Optical Inversion of Camphor” in Journal of the Chemical Society71 (1897), 956; “Derivatives of Camphoric Acid. Part II. Optically Inactive Derivatives” ibid., p. 962; “Racemism and Pseudoracemiasm” ibid., p. 989; “Enantiomorphism,” ibid., 73 (1898), 606; “The Separation of Optical Isomer Ides” in Proceeding of the Chemical Society, (1898), 113; and “Characterization of Racemic Compounds” ibid., p. 219; and in Journal of the Chemical Society75 (1899), 36.

Other works include “Resolution of Tetrahydro-p-toluquinaldine Into Its Optically Active Components,” in Journal of the Chemical Society91 (1907), 458, written with T. C. Beck; “The Resolution of Externally Compensated Dihydro-α-methylindole” ibid., 85 (1904), 1330, written with G. Clarke, Jr.; “The Alkyl Compounds of Gold,” ibid., 91 (1907), 2061; “l-Methycyclohexlidence-4-acetic acid,” in Proceedings of the Chemical Society22 (1906), 107, written with W. H. Perkin Jr.; “Relation Between Crystalline From and Chemical Constitution of the Picryl Derivatives,” in Proceedings of the Royal Society,80A (1908), 557, written with G. Jerusalem; and the following works, written with W. Barlow: “A Development of the Atomic Theory Which Correlates Chemical and Crtystalline Structure and Leads to a Demonstration of the Nature of Valency,” in Journal of the Chemical Society89 (1906), 1675; “The Relation Between the Crystalline Form and the Chemical Constitution of Simple Inorganic Substances,“ibid., 91 (1907), 1150; and “Note on the Theory of Valency” in Proceedings of the Chemical Society,23 (1907), 15.

Pope’ works at the University Chemical Laboratory, Cambridge (1908–1939), include “The Optical Activity of Compounds Having Simple Molecular Structure,” in Journal of the Chemical Society93 (1908), 796, written with J. Read; “Experiments on the Synthesis of l-Methyl-cyclohexylidene-4-acetic Acid” ibid., p. 1075, written with W . J . Perkin, Jr.; “On Polymorphism, With Especial reference to Sodium Nitrate and Calcium Carbonate” ibid., p. 1528, written with W. Barlow; “Optically Active Substances Which Contain No Asymmetric Atom” (Preliminary Note), in Proceedings of the Chemical Society25 (1909), 83, written with W. H. Perkin and O. Wallach; “The Crystallization of Externally Compensated Mixtures,” in Journal of the Chemical Society,95 (1909), 103, written with F. S. Kipping; “The Condensation of Oxymethylenecamphor With Primary and Secondary Amino Compounds,” ibid., p. 171, written with J. Read; “The Alkyl Compounds of Platinum,” ibid., p. 571, written with S. J. Peachey; and “Ueber optisch active Substanzen, die kein asymmetrisches Atom enthalten,” in Justus Liebigs Annalen der Chemie, 371 (1909), 180, written with W. H. Perkin and O. Wallach.

See also “The Resolution of Externally Compensated Acids and Bases,” in Journal of the Chemical Society, 97 (1910), 987; “Externally Compensated Tetrahydroquinaldine (Tetrahydro-2-methylquinoline) and Its Optically Active Components,” ibid., p. 2199, written with J. Read; “The Resolution of Externally Compensated Pavine and α-Bromocamphor-ω-Sulphonic Acid,” ibid., p. 2207, written with C. S. Gibson; “The Rotatory Powers of the Salts of d- and l-Camphor-β-Sulphonic Acid With d- and l-Pavine,” ibid., p. 2211, written with C. S. Gibson; “The Relation Between the Crystal Structure and the Chemical Composition, Constitution, and Configuration of Organic Substances,” ibid., p. 2308, written with W. Barlow; “Optically Active Derivatives of l-Methylcyclohexylidene-4-acetic Acid,” ibid., 99 (1911), 1510, written with W. H. Perkin, Jr.; “Dihydroxydihydrindamine and Its Resolution Into Optically Active Components,” ibid., p. 2071, written with J. Read; “Asymmetric Quinquevalent Nitrogen Compounds of Simple Molecular Constitution,” ibid., 101 (1912), 519, written with J. Read; “Some Mixed Phosphonium Derivatives,” ibid., p. 735, written with C. S. Gibson; “The Alkaloidal Salts of Phenylmethylphosphinic Acid,” ibid., p. 740, written with C.S. Gibson; “The Resolution of Benzoylalanine Into Its Optically Active Components,” ibid., p. 939, written with C. S. Gibson; “The Externally Compensated and Optically Active Hydroxyhydrindamines, Their Salts and Derivatives,” ibid., p. 758, written with J. Read; “The Resolution of sec-Butylamine Into Optically Active Components,” ibid., p. 1702, written with C. S. Gibson; “The Relation Between Constitution and Rotatory Power Amongst Derivatives of Tetrahydroquinaldine,” ibid., p. 2309, written with T. F. Winmill; “The Absence of Optical Activity in the α and β-2: 5-Dimethylpiperazines,” ibid., p. 2325, written with J. Read; “A Noval Method for Resolving Externally Compensated Amines; Derivatives of d- and l-Oxymethylencamphor,” ibid., 103 (1913), 444, written with J. Read; “The Ten Stereoisomeric Tetrahydroquinaldinomethylenecamphors,” ibid., p. 1515, written with J. Read; and “The Resolution of 2 : 3-Diphenyl-2 : 3-Dihydro-1 : 3 : 4-Naphthaisotriazine Into Optically Active Components,” ibid., p. 1763, written with Clara M. Taylor.

Other works include “Ueber das Quecksilber-dibenzyl,” in Berichte der Deutschen chemischen Gesellschaft, 46 (1913), 352; “The Relation Between Optical Activity and Molecular Complexity,” in Transactions of the Faraday Society, 10 (1914), 118, written with J. Read; “Optically Active Substances of Simple Molecular Constitution,” in Proceedings of the Cambridge Philosophical Society, Mathematical and Physical Sciences (1914), written with J. Read; British Association. Section B. (Australia, 1914) Address to the Chemical Section; “The Chemical Significance of Crystalline Form,” in Journal of the American Chemical Society, 36 (1914), 1675, written with W. Barlow; “The Identity of the Suposed β-2: 5-Dimethylpiperazine,” in Journal of the Chemical Society, 105 (1914), 219, written with J. Read; “The Variable Rotatory Powers of the d-α-Bromocamphorsulphonates,” ibid., p. 800, written with J. Read; “The Optical Activity of Compounds of Simple Molecular Constitution. Ammonium d- and l-Chloroiodomethanesulphonates,” ibid., p. 811, written with J. Read; “Enantiomorphism of Molecular and Crystal Structure,” ibid., 107 (1915), 700, written with W. Barlow; “On Topic Parameters and Morphotopic Relationships,” “On Topic Parameters and Morphotopic Relationships,” in Philosophical Magazine, 29 (1915), 745, written with W. Barlow; “The Future of Pure and Applied Chemistry. Presidential Address,” in Journal of the Chemical Society, 113 (1918), 289; “Chemistry in the National Service. Presidential Address,” ibid., 115 (1919), 397; “β;β;′-Dichlorodiethyl Sulphide,” ibid., 117 (1920), 271, written with C. S. Gibson; “The Preparation and Physical Properties of Carbonyl Chloride,” ibid., p. 1410, written with R. H. Atkinson and C. T. Heycock; “Triphenylarsine and Diphenylarsenious Salts,” ibid., p. 1447, written with E. E. Turner; “Studies on Photographic Sensitisers. Part I. The Isocyanine Dyestuffs,’s in Photographic Journal (May 1920), written with W. H. Mills; and “Studies on Photographic Sensitisers. Part II. The Carbocyanines,” ibid. (Nov. 1920), written with W. H. Mills.

See also “The Interaction of Sulphur Monochloride and Substituted Ethylenes,” in Journal of the Chemical Society, 119 (1921), 396, written with J. L. B. Smith; “The Interaction of Ethylene and Sulphur Monochloride,” ibid., p. 634, written with F. G. Mann and R. H. Vernon; “Production and Reactions of β;β;’-Dichlorodiethyl Sulphide,” ibid., 121 (1922), 594, written with F. G. Mann; “isoQuinoline and the isoQuinoline-reds,” ibid., p. 1029, written with J. E. G. Harris; “The Sulphilimines, a New Class of Organic Compounds Containing Quadrivalent Sulphur,” ibid., p. 1052, written with F. G. Mann; “The Chlorinated Dialkyl Sulphides,” ibid., p. 1166, written with J. L. B. Smith; “The β-Chlorovinylarsines,” ibid., p. 1754, written with F. G. Mann; “The αα’-Dichlorodialkyl Sulphides,” ibid., 123 (1923), 1172, written with F. G. Mann; “The Isomeric Trithioacetaldehydes,” ibid., p. 1178, written with F. G. Mann; “The Preparation of Sulphuryl Chloride,” in Recueil des travaux chimiques des Pays-Bas et de la Belgique, 42 (1923), 939; “The Optically Active Sulphilimines,” in Journal of the Chemical Society, 125 (1924), 911, written with F. G. Mann; and “The Resolution of dl-Diphenylpropylenediamine and dl-1 : 4-Diphenyl-2-methylpiperazine,” ibid., p. 2396, written with F. S. Kipping.

See also “1 : 2 : 3-Triaminopropane and Its Complex Metallic Compounds,” in Proceedings of the Royal Society, 107A (1925), 80, written with F. G. Mann;“β;β;’β;” -Triaminotriethylamine and Its Compounds,” ibid., 109A (1925), 444, written with F. G. Mann; “Dissymmetry and Asymmetry of Molecular Configuration,” in Journal of the Society of Chemical Industry, 44 (1925), 833, written with F. G. Mann; “The Complex Salts of β;β;’β;”Triaminotriethylami ne With Nickel and Palladium,” in Journal of the Chemical Society, 129 (1926), 482, written with F. G. Mann;“γγ′γ″-Triaminotripropylamine and Its Complex Compounds With Nickel,” ibid., p. 489; “The Resolution of dl-Alanine and the Formation of trans-2 : 5-Dimethylpiperazine,” ibid., p. 494, written with F. S. Kipping;“Preparation and Resolution of dl-cis-2 5-Dimethylpiperazine,” ibid., p . 1076, written with F . S . Kipping ; “The Configuration of the Bistriaminopropane Metallic Complexes,“ibid., p. 2675, written with F. G. Mann; “The Optically Active spiro-5; 5-Dihydantoins,” in Proceedings of the Royal Society, 134A (1931), 357, written with J. B. Whitworth; “The Symmertrical spiro-Heptanediamine and Its Resolution Into opticalyy Active Coponents,” in Proceedings of the Royal Society, 154A (1936), 53, written with S. E. Janson; “Optically Active Di-and terta-methylspiro-5; 5-dihydantoins,” ibid155A (1936), 1, written with J. B. Whitworth; “Preparation of ββ′-dichlorodiethyl sulphide” (Brit. Pat. 142875), in Journal of the Chemical Society, 118 pt. 1 (1920), 523, written with C. S. Gibson and H.F. Thuillier; “Production of Aromatic Arsenic Compounds (mono- and di-aryl Arsenious Haloids)” (Britt. Pat. 142880), ibid., p. 578; and “Production and Utilisation of Sulphur Dichloride” (Brit. Pat. 142879), ibid., pt. 2, p. 484, written with C. T. Heycock.

The following papers on crystallography were published from the City and Guilds of London Institute (1896–1899): “Angular Measurement of Optic Axial Emergences,” in Proceedings of the Royal Society, 60 (1896), 7; “Die Krystallformen der Natriumsalze der substituirten Anilsauren,” ibid., 24 (1895), 529’ “Die Krystallformen der stereoisomeren αα’-Dimethylpimelinsauren,” ibid., 533; “Die Krystallform einiger neuer Halogenderivate des Camphers,” in Zeitschrift f̈r Kristallographie and Mineralogie, organischer Verbindungen,” ibid., p. 450; “Ein bemerkenswerther Fall von Phosphorescenz,” ibid ., 25 (1895), 567; “Ueber die Messung Winkels der optischen Axen,“ibid., 26 (1896), 589; “Ueber optisches Drehungsvermögen,” ibid., 27 (1896), 406; “Die Refractioonsconstanten krystallisirter Salze,” ibid., 28 (1897), 113; “Eine Acetonverbindung der Camphersaure,“ibid., 28 (1897), 128; “Ueber Racemie und pseudoracemie,” ibid., 30 (1898), 443, written with F. S. Kipping; “Ueber Enantiomorphismus,” ibidp. 472, written with F. S. Kipping; “Eine nicht Zwillingsartige Verwachsung von Natriumchloratkrystallen,” ibid., p 31 (1899), 15; “Eineneue, partiell racemische Verbindung,”ibidp. 11, written with S. J. Peachey; and “Ueber die Krystallformen einiger organischer Verbindungen,” ibid., p. 115.

Frederick George Mann