Australian Journal of Chemistry Australian Journal of Chemistry Society
An international journal for chemical science

On the Solid-State Isomerization of Terpinolene Tetrabromide

Paul V. Bernhardt A B , Raymond M. Carman A and Tri T. Le A
+ Author Affiliations
- Author Affiliations

A School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Qld 4072, Australia.

B Corresponding author. Email:

Australian Journal of Chemistry 63(3) 458-462
Submitted: 24 November 2009  Accepted: 16 January 2010   Published: 26 March 2010


The isomerization of terpinolene tetrabromide from the cis-2,4- (diaxial) dibromo isomer (A) to the more stable trans-2,4- (equatorial–axial) compound (B) has been investigated in the solid state. The progress of the solid-state reaction as a function of time was followed by solution NMR analysis, and, more effectively, by micropowder X-ray diffraction of the bulk material in situ. Characterization of the solid-state reaction mixture is facilitated by the existence of X-ray crystal structures of both compounds A (monoclinic) and B (reported previously) in addition to a new triclinic polymorph of compound A reported herein, all three forms being observed by powder X-ray diffraction.


R.M.C. thanks Dr James De Voss for providing office and laboratory space and Dr Joanne Blanchfield and the De Voss research students for helpful practical assistance.


[1]   Gallagher M. J. , M.Sc. Thesis: Studies in terpene chemistry 1960, pp. A1–A4 (Brisbane: The University of Queensland).

[2]   R. M. Carman, B. N. Venzke, Aust. J. Chem. 1971, 24,  1905.
        |  CAS |  

[3]   R. M. Carman, B. N. Venzke, Aust. J. Chem. 1974, 27,  383.
        |  CAS |  

[4]   P. V. Bernhardt, R. M. Carman, T. T. Le, Aust. J. Chem. 2005, 58,  535.
        | CrossRef |  CAS |  

[5]   O. Wallach, Liebigs Ann. 1885, 230,  262.

[6]   C. Hintze, Z. Kristallogr. 1885, 10,  258.

[7]   J. A. Henry, H. Paget, J. Chem. Soc. 1931,  25.
        | CrossRef |  CAS |  

[8]   Owen W. R. , M.Sc. Thesis: Studies in the chemistry of alphaphellandrene 1955 (Brisbane: The University of Queensland).

[9]   M. D. Sutherland, J. W. Wells, J. Org. Chem. 1956, 21,  1272.
        | CrossRef |  CAS |  

[10]   J. D. Briasco, J. Murray, J. Prac. Chem. 1952, 2,  187.
        |  CAS |  

[11]   J. D. Dunitz, J. Bernstein, Acc. Chem. Res. 1995, 28,  193.
        | CrossRef |  CAS |  

[12]   McCrone W. C. , Polymorphism in Physics and Chemistry of the Organic Solid State (Eds D. Fox, M. M. Labes, A. Weissberger) 1965, Vol. 11, pp. 726–767 (Interscience: New York, NY).

[13]   G. Kaupp, CrystEngComm 2003, 5,  117.
        | CrossRef |  CAS |  

[14]   G. Kaupp, Top. Curr. Chem. 2005, 254,  95.
        |  CAS |  

[15]   L. J. Farrugia, J. Appl. Cryst. 1999, 32,  837.
        | CrossRef |  CAS |  

[16]   Sheldrick G. M. , SHELX97 – Programs for Crystal Structure Analysis (Release 97–2) 1998 (Universität Göttingen: Göttingen, Germany).

[17]   L. J. Farrugia, J. Appl. Cryst. 1997, 30,  565.
        | CrossRef |  CAS |  

[18]   B. E. Warren, J. Am. Ceram. Soc. 1934, 17,  249.
        | CrossRef |  CAS |  

# According to his MSc dissertation, Owen heated one of his preparations of terpinolene tetrabromide on a water bath to remove excess bromine, but then obtained compound B (‘β’). He also reports that an old comparison sample available in the Sutherland laboratory, although still crystalline, was ‘much decomposed’, and afforded compound B (‘β’) on recrystallization. It is not clear in his work how Owen distinguished his α compound, mp 116–117.5°C (now known to be compound A) from his β isomer (compound B), mp 117–118°C.

Rent Article (via Deepdyve) Supplementary MaterialSupplementary Material (780 KB) Export Citation