The cooperative picture drawn above suggested other experiments. Polyisocyanates were synthesized in which a few chiral pendants were dispersed among
large numbers of achiral pendants along the chain backbone. Large excesses of one
helical sense were observed, as measured by the chiral optical properties, with these
observations quantitatively fitting to Ising models (the mathematical formalisms of
one dimensional paramagnetic materials). This theoretical connection was developed by Jonathan Selinger of the Navel Research Laboratories. Further experiments
involved synthesis of polyisocyanates in which enantiomeric units competitively
favoring opposing helical senses were randomly dispersed along the chain backbone. Remarkably, slight excess of one of the competitive chiral units was adequate
to produce polymers with large excesses of one helical sense, again described in
quantitative detail by Selinger’s theoretical work. In an interesting aspect of this
work, which finds an analogy in human experience, the theory and the experimental
results show that the larger the energy favoring one helical sense by the chiral group
in excess in this experiment, the less influence this chiral group has on its preferred
helical sense [9–11].
These kinds of experiments were appropriately termed the “sergeants and
soldiers effect” and “majority rule,” and were found by other research groups to
apply to other helical polymers and to varieties of materials subject to cooperative
phenomena associated with chirality, and even with two dimensional materials.
Literature searches under these metaphors yield hundreds of references spanning a
wide variety of fields that involve cooperative effects on chiral measurements.
In summary, therefore, Staudinger’s efforts in setting the stage for studies of the
properties of polymers are demonstrated across the spectrum of polymer classes in
stereochemical phenomena associated with chirality studied at the Herman F. Mark
Polymer Research Institute at the Polytechnic Institute of Brooklyn [12–17].
References
1. Nobelprize.org (1964) Hermann Staudinger – Nobel lecture, December 11, 1953: Macromolecular chemistry. In: Nobel lectures, chemistry 1942–1962. Elsevier, Amsterdam. http://
www.nobelprize.org/nobel_prizes/chemistry/laureates/1953/staudinger-lecture.pdf
2. Green MM, Garetz BA (1984) Tetrahedron Lett 25:2831
3. Farina M (1987) The stereochemistry of linear macromolecules, vol 17, Topics in stereochemistry. Wiley, New York, p 1
4. Mislow K, Bickart P (1976/1977) Israel J Chem 15:1
5. Pino P (1965) Advs Polym Sci 4:393
6. Goodman M, Chen SC (1970) Macromolecules 3:398
7. Green MM, Peterson NC, Sato T, Teramoto A, Lifson S (1995) Science 268:1860
8. Green MM, Khatri C, Peterson NC (1993) J Amer Chem Soc 115:4941
9. Green MM, Park J-W, Sato T, Teramoto A, Lifson S, Selinger RLB, Selinger JV (1999)
Angew Chem Int Ed 38:3139
10. Green MM (2000) A model for how polymers amplify chirality. In: Berova N, Nakanishi K,
Woody RW (eds) Circular dichroism-principles and applications, 2nd edn. Wiley-VCH,
New York, Chap 17
Stereochemical Studies at the Herman F. Mark Polymer Research Institute
269
large numbers of achiral pendants along the chain backbone. Large excesses of one
helical sense were observed, as measured by the chiral optical properties, with these
observations quantitatively fitting to Ising models (the mathematical formalisms of
one dimensional paramagnetic materials). This theoretical connection was developed by Jonathan Selinger of the Navel Research Laboratories. Further experiments
involved synthesis of polyisocyanates in which enantiomeric units competitively
favoring opposing helical senses were randomly dispersed along the chain backbone. Remarkably, slight excess of one of the competitive chiral units was adequate
to produce polymers with large excesses of one helical sense, again described in
quantitative detail by Selinger’s theoretical work. In an interesting aspect of this
work, which finds an analogy in human experience, the theory and the experimental
results show that the larger the energy favoring one helical sense by the chiral group
in excess in this experiment, the less influence this chiral group has on its preferred
helical sense [9–11].
These kinds of experiments were appropriately termed the “sergeants and
soldiers effect” and “majority rule,” and were found by other research groups to
apply to other helical polymers and to varieties of materials subject to cooperative
phenomena associated with chirality, and even with two dimensional materials.
Literature searches under these metaphors yield hundreds of references spanning a
wide variety of fields that involve cooperative effects on chiral measurements.
In summary, therefore, Staudinger’s efforts in setting the stage for studies of the
properties of polymers are demonstrated across the spectrum of polymer classes in
stereochemical phenomena associated with chirality studied at the Herman F. Mark
Polymer Research Institute at the Polytechnic Institute of Brooklyn [12–17].
References
1. Nobelprize.org (1964) Hermann Staudinger – Nobel lecture, December 11, 1953: Macromolecular chemistry. In: Nobel lectures, chemistry 1942–1962. Elsevier, Amsterdam. http://
www.nobelprize.org/nobel_prizes/chemistry/laureates/1953/staudinger-lecture.pdf
2. Green MM, Garetz BA (1984) Tetrahedron Lett 25:2831
3. Farina M (1987) The stereochemistry of linear macromolecules, vol 17, Topics in stereochemistry. Wiley, New York, p 1
4. Mislow K, Bickart P (1976/1977) Israel J Chem 15:1
5. Pino P (1965) Advs Polym Sci 4:393
6. Goodman M, Chen SC (1970) Macromolecules 3:398
7. Green MM, Peterson NC, Sato T, Teramoto A, Lifson S (1995) Science 268:1860
8. Green MM, Khatri C, Peterson NC (1993) J Amer Chem Soc 115:4941
9. Green MM, Park J-W, Sato T, Teramoto A, Lifson S, Selinger RLB, Selinger JV (1999)
Angew Chem Int Ed 38:3139
10. Green MM (2000) A model for how polymers amplify chirality. In: Berova N, Nakanishi K,
Woody RW (eds) Circular dichroism-principles and applications, 2nd edn. Wiley-VCH,
New York, Chap 17
Stereochemical Studies at the Herman F. Mark Polymer Research Institute
269