Folder B.20.1: 'Free valence paper', 1950.

Extensive correspondence, May-July 1950, with collaborators, H.C. Longuet-Higgins, and with R. Daudel regarding paper 'Free-valence in unsaturated hydrocarbons'.

Typescript draft by Longuet-Higgins.

3 pp. typescript draft by Coulson 'Free valence in radical reactions'.

Set of MS. notes 'Free valence changes due to resonance'.

Folder B.20.2: 'Law of alternating polarity', 1957

8 pp. MS. draft 'Some notes on the law of alternating polarity'. Miscellaneous MS. notes.

Correspondence, January-December 1957, with B.M. Wepster and S. Basu, on points relating to this subject.

7 pp. untitled typescript (differs from the ms. noted above). This paper is believed to be unpublished.

Folder B.20.3: 'Two notes on the shape of charge clouds near a hydrogen atom', 1958>

9 pp. MS. and 9 pp. typescript draft, and some loose papers and MS. notes.

Copies of CAC's letters to W. Cochrane, 1958, re Cochrane's paper at a M.I.T. conference. This paper seems to have been the basis of CAC's own work on the topic. He submitted the above ms. for publication in Acta Crystallographica, but it does not seem to have been published.

Folder B.20.4: 'Calculation of the difference in the energies of the two systems in Hückel's approximation', 1963-1965.

Correspondence with collaborator, J. Koutecky, 1965.

39 pp. typescript (probably by Koutecky). The paper was never published.

Folder B.20.5: 'Correspondence and working papers for possible publication on diamond', 1964-1965.

Miscellaneous MS. notes and correspondence with others working on the subject.

Folder B.20.6: 'Halogens', 1964-1966.

Notes on the literature, miscellaneous ms. notes, related offprints, and correspondence with D. Mayers and L.S. Bartell.

Folder B.20.7: 'B₂O₃H₂', 1964-1970.

MS. draft (photocopy) of 'Boron-Oxygen bonds, the case of H₂B₂O₃' sent by Coulson to collaborator, J.P.M. Bailey, for comment. Correspondence with Bailey regarding joint work.

Correspondence with T.W. Dingle regarding their earlier collaborative paper 'The B-O bond lengths in boron-oxygen compounds'.

Notes by Coulson on work of others, with related correspondence.

Folder B.20.8: 'Localised benzene regions in condensed aromatics', 1967.

'Double-bond character', MS. draft. Notes on the literature.

Folder B.20.9: 'History of Theoretical Chemistry', 1971.

Closing speech by Coulson at Fourth Canadian Symposium on Theoretical Chemistry, University of British Columbia, August 1971.

16 pp. MS. and 12 pp. typescript. Miscellaneous MS. notes collected for the speech. Correspondence regarding proposal to publish the lecture.

Folder also includes a typescript of Coulson's opening remarks at Summer School on Quantum Chemistry, Yugoslavia, 1967, and related correspondence.

Folder B.20.10: 'Problems with the helicenes', 1970-1972.

Carbons of 2 of Coulson's letters on the subject, MS. notes, and related offprint.

Folder B.20.11: One folder of miscellaneous MS. notes, one labelled 'Coulson's policy', n.d.

B.20.12: 'The electronic structure of molecules from the standpoint of the theory of molecular orbitals', 1934. Thesis submitted for the Fellowship examination at Trinity College, Cambridge.

Coulson was elected to this Prize Fellowship (his thesis was examined by G.H. Hardy) at the same time as Douglas Lea. Coulson typed the thesis himself with numerous figures and charts in his own hand. It was never published.

Several loose sheets have been inserted in the front of the bound volume. These include an introductory note to accompany the thesis on its submission to Trinity, a list of references titled 'Electronic structure of polyatomic molecules and valence', notes on a paper published in Modern Chemistry by Linus Pauling in 1938, and one letter (1964) loaning the thesis to a colleague.