On the crystal structures and melting point alternation of the n-alkyl carboxylic acids

New Journal of Chemistry

Volumn 28, Issue 1, 2004, Pages 104-114

  Bond, Andrew D ^a,b  

^a UNIVERSITY OF CAMBRIDGE   (United Kingdom)

^b UNIVERSITY OF SOUTHERN DENMARK   (Denmark)

Author keywords

[No Author keywords available]

Indexed keywords

CARBOXYLIC ACID DERIVATIVE;

ANALYTIC METHOD; ARTICLE; CHEMICAL BOND; CHEMICAL MODIFICATION; CHEMICAL REACTION; CHEMICAL STRUCTURE; CORRELATION ANALYSIS; CRYSTAL STRUCTURE; CRYSTALLIZATION; DENSITY; DIMERIZATION; HYDROGEN BOND; MELTING POINT; PRIORITY JOURNAL; STRUCTURE ANALYSIS;

EID: 1242329153     PISSN: 11440546     EISSN: None     Source Type: Journal    
DOI: 10.1039/b307208h     Document Type: Article

References (55)

1. (a) The first note regarding melting point alternation is attributed to Baeyer in an article dealing specifically with the n-alkyl carboxylic acids: A. Baeyer, Ber. Chem. Ges., 1877, 10, 1286;
2. (b) see also: A. W. Ralston, Fatty Acids and Their Derivatives, John Wiley & Sons, New York, 1948.
3. A. Müller, Proc. R. Soc. London, Ser. A, 1927, 114, 542.
4. (a) W. H. Bragg, Proc. Phys. Soc. (London), 1921, 34, 33;
5. (b) W. H. Bragg, Proc. Phys. Soc. (London), 1922, 35, 167.
6. (a) T. R. Lomer, Nature (London), 1955, 176, 653;
7. (b) T. R. Lomer and R. M. Spanswick, Acta Crystallogr., 1961, 14, 312;
8. (c) T. R. Lomer, Acta Crystallogr., 1963, 16, 984.
9. (a) E. von Sydow, Acta Crystallogr., 1954, 7, 529;
10. (b) A. Abrahamsson and E. von Sydow, Acta Crystallogr., 1954, 7, 591;
11. (c) E. von Sydow, Acta Crystallogr., 1954, 7, 823;
12. (d) E. von Sydow, Acta Crystallogr., 1955, 8, 845;
13. (e) E. von Sydow, Acta Chem. Scand, 1956, 10, 1;
14. (f) K. Larsson and E. von Sydow, Acta Chem. Scand, 1966, 20, 1203.
15. (a) M. Goto and E. Asada, Bull. Chem. Soc. Jpn., 1978, 51, 70;
16. (b) M. Goto and E. Asada, Bull. Chem. Soc. Jpn., 1978, 51, 2456;
17. (c) M. Goto and E. Asada, Bull. Chem. Soc. Jpn., 1980, 53, 2111;
18. (d) M. Goto and E. Asada, Bull. Chem. Soc. Jpn., 1984, 57, 1145.
19. A. I. Kitaigorodskii, Molecular Crystals and Molecules, Academic Press, New York, 1973, p. 48ff.
20. K. Larsson, J. Am. Oil Chem. Soc., 1966, 43, 559.
21. R. Boese, H.-C. Weiss and D. Bläser, Angew. Chem., Int. Ed., 1999, 38, 988.
22. V. R. Thalladi, R. Boese and H.-C. Weiss, Angew. Chem., Int. Ed., 2000, 39, 918.
23. V. R. Thalladi, R. Boese and H.-C. Weiss, J. Am. Chem. Soc., 2000, 122, 1186.
24. V. R. Thalladi, M. Nüsse and R. Boese, J. Am. Chem. Soc., 2000, 122, 9227.
25. For the polymorphic acids, the various crystal modifications are denoted A, B, C, etc. for the even acids and A′, B′, C′, etc. for the odd acids. The classification is based on the magnitude of the perpendicular separation of crystallographically equivalent planes passing through the terminal methyl groups. The crystal modification with the longest observed separation is denoted A/ A′, the second longest B/B′, etc. For a detailed discussion, see ref. 17.
26. E. von Sydow, Acta Crystallogr., 1955, 8, 810.
27. V. Vand, W. M. Morley and T. R. Lomer, Acta Crystallogr., 1951, 4, 324.
28. V. Malta, G. Celotti, R. Zannetti and A. F. Martelli, J. Chem. Soc. B, 1971, 548.
29. E. von Sydow, Arkiv Kemi, 1956, 9, 231.
30. A. I. Kitaigorodskii, Organic Chemical Crystallography, Consultants Bureau, New York, 1961, p. 208ff.
31. (a) F. Holtzberg, B. Post and I. Fankuchen, Acta Crystallogr., 1953, 6, 127;
32. (b) I. Nahringbauer, Acta Crystallogr., Sect. B, 1978, 34, 315.
33. (a) R. E. Jones and D. H. Templeton, Acta Crystallogr., 1958, 11, 484;
34. (b) I. Nahringbauer, Acta Chem. Scand., 1970, 24, 453;
35. (c) P.-G. Jönsson, Acta Crystallogr., Sect. B, 1971, 27, 893;
36. (d) R. Boese, D. Bläser and A. Bäumen, Acta Crystallogr., Sect. C, 1999, 55, IUC9900001.
37. F. J. Streiter and D. H. Templeton, Acta Crystallogr., 1962, 15, 1233.
38. F. J. Streiter and D. H. Templeton, Acta Crystallogr., 1962, 15, 1240.
39. R. F. Scheuerman and R. L. Sass, Acta Crystallogr., 1962, 15, 1244.
40. J. E. Davies and A. D. Bond, Acta Crystallogr., Sect. E, 2001, 57, o947.
41. The same trend may be expressed either in terms of unit-cell volume, packing coefficients or calculated lattice-binding energies (see ESI). The densities and unit-cell volumes of the full data sets, although collected over a range of temperatures, alternate in an essentially identical manner, so that the subsequent discussion based on atomic coordinates derived from the full data sets is valid.
42. 1/c or C2/c.
43. 1 is a true unit cell for each structure in space group P1. It does not take proper account of the crystal symmetry.
44. 10, respectively. In the case of the odd diacids, the fit refers to the β polymorph; the α polymorph of the odd diacids displays a different arrangement.
45. G. R. Desiraju and T. Steiner, The Weak Hydrogen Bond in Structural Chemistry and Biology (IUCr Monographs on Crystallography 9), Oxford University Press, New York, 1999, p. 122ff.
46. The same effect is seen in the α,ω-alkanedicarboxylic acids.
47. In the previous literature describing the structures of the n-alkyl carboxylic acids (most notably Kitaigorodskii's description in ref. 18), the direction of the offset is described as opposite in the odd and even acids. This is somewhat misleading. The direction of the offset is identical in each case. The different arrangements at the methyl group interface arise simply from having odd or even numbers of carbon atoms in the n-alkyl chains.
48. 3 contacts resembles that of C-X⋯X-C contacts (X = halogen) commonly observed in crystal structures: V. R. Pedireddi, D. S. Reddy, B. S. Goud, D. C. Craig, A. D. Rae and G. R. Desiraju, J. Chem. Soc., Perkin Trans 2, 1994, 2353. The contacts between terminal C-C bond vectors that are parallel resemble type I contacts, while those between terminal C-C bond vectors that are close to perpendicular resemble type II contacts.
49. The herringbone arrangement is comparable to that observed in monolayers of the even alkanes adsorbed on a graphite surface: T. Arnold, R. K. Thomas, M. A. Castro, S. M. Clarke, L. Messe and A. Inaba, Phys. Chem. Chem. Phys., 2002, 4, 345. In similar monolayers of the odd alkanes the n-alkyl chains are parallel but maintain a side-on arrangement of methyl groups: T. Arnold, C. C. Dong, R. K. Thomas, M. A. Castro, A. Perdigon, S. M. Clarke and A. Inaba, Phys. Chem. Chem. Phys., 2002, 4, 3430.
50. The herringbone arrangement is comparable to that observed in monolayers of the even alkanes adsorbed on a graphite surface: T. Arnold, R. K. Thomas, M. A. Castro, S. M. Clarke, L. Messe and A. Inaba, Phys. Chem. Chem. Phys., 2002, 4, 345. In similar monolayers of the odd alkanes the n-alkyl chains are parallel but maintain a side-on arrangement of methyl groups: T. Arnold, C. C. Dong, R. K. Thomas, M. A. Castro, A. Perdigon, S. M. Clarke and A. Inaba, Phys. Chem. Chem. Phys., 2002, 4, 3430.
51. A. D. Bond and J. E. Davies, Acta Crystallogr., Sect. E, 2002, 58, 196.
52. o.
53. 7 is 4.840(8) Å, significantly shorter than in any of the other structures.
54. This is the first application of the parallelogram-trapezoid model to molecules with different end groups. It is not strictly necessary to employ "double" parallelograms and trapezoids as the most basic units - the model may still be employed using single parallelograms and trapezoids if it is also noted that the two ends of each shape will have different packing requirements, that is the carboxyl groups will always form centrosymmetric dimers and the methyl groups would be expected to form "optimal staggered" contacts. The use of the doubled entities not only simplifies the discussion, but is also based on sensible "supramolecular" principles: the hydrogen-bond motif formed by the carboxyl groups within each dimer contributes sufficiently to the overall lattice binding energy that it is not disrupted in any of the structures.
55. This difference was noted previously by von Sydow within ref. 17.