Spiro macromolecule

Macromolecule consisting of an uninterrupted sequence of rings with adjacent rings having one atom in common (spiro macromolecule) or two or more atoms in common (ladder macromolecule). 

Note A spiro macromolecule is a double-strand macromolecule with adjacent constitutional units joined to each other through three atoms, two on one side and one on the other side of each constitutional unit. 

Note 1 A polymer, the macromolecules of which are spiro macromolecules, is termed a spiro polymer. 

Photoresponsive polymers can be obtained by introducing photochromic units, such as azobenzene or spiropyran groups, into the macromolecules of polymeric compounds. As described in Chapter 1 of this book, photochromic compounds can exist in two different states, such as two isomeric structures that can be inter-converted by means of a light stimulus, and the relative concentrations of which depend on the wavelength of the incident light. For instance, in azobenzene compounds, photochromism is due to trans-cis photoisomerization around the N=N double bond, while in spiropyran compounds photochromism involves interconversion between the neutral spiro form and the zwitterionic merocyanine form (Figure 1). 

On the basis of fluorescence measurements, the driving force responsible for the photoinduced conformational change was attributed to interactions between the photochromic side chains, which differ depending on whether they are in the zwit-terionic merocyanine form or the apolar spiro form. In the dark, the merocyanine units have a strong tendency to give dimeric species as a result the macromolecules are forced to adopt a disordered structure. When the side chains are photoisome-rized to the spiro form, such dimers are destroyed, and the macromolecules assume the helical structure.1631... 

Prior knowledge has shown the value of introducing cyclopropane systems into macromolecules. A number of isolated studies have been carried out on the polymerization of such structures (10, 14, 28), principally on cyclopropane (28) and isopropylcyclopropane. Attention was directed toward three types of structures—i.e., the 1,1-dichlorocyclopro-panes, the bicyclo[n.l.0]alkanes, and the spiro [2.n] alkanes. In each case, the effects involved appeared highly complex the polymers formed have not yet all been characterized, and it is thought that a comparison with the model structures expected from rupture of one or the other of the cyclopropane bonds may be of value. 

Space limitations do not permit the description of other varieties of rigid chain macromolecules, such as semiladder and spiro siructures, which are of lesser current commercial importance. 

J.H. Ge, M. Trujillo-Lemon, and J.W. Stansbury, A mechanistic and kinetic study of the photoinitiated cationic double ring-opening polymerization of 2-methylene-7-phenyl-l,4,6,9-tetraoxa-spiro[4.4]nonane. Macromolecules 2006, 39(26), 8968-8976. 

Linear macromolecules having two hydroxyl end-groups were exclusively detected in polyesters obtained by bulk polymerization of spiro compounds such as 0,0 -phthalid-3-ylidenecatechol and 4-methyl-0,0 -phthalid-3-... 

Jiang JX, Layboum A, Clowes R et al (2010) High surface area contorted conjugated microporous polymers based on spiro-bipropylenedioxythiophene. Macromolecules... 

W.Y. Huang, S.Y. Huang, Sterically encumbered lluorene-based poly(arylene ether)s containing spiro-annulated substituents on the main chain. Macromolecules 43 (24) (2010) 10355-10365. 

Macrocyclic oligomer precursors of polycarbonates, PET, polymers of amides, etherketones, and ethersulfones are candidates for further study of macrocyclic oligomer polymerization thermodynamics [6]. Research extends to cyclic arylates (cyclic aryl-aryl esters) and cyclic alkyl aryl esters going back to isolating a cyclic trimer of poly(ethylene-terephthalate) in 1954 [13]. Much of the work on macrocyclic oligomers as precursors to high-MW macromolecules starts with spiro(bis)indane (SBI) biphenyl monomer to produce macrocyclic carbonates. 

Kapnistos Michael, Hinrichs Axel, Vlassopoulos Dimitris, Anastasiadis Spiros, Stammer Andreas, and Wolf Bernhard Anton. Rheology of a lower critical solution temperature binary polymer lend in the homogeneous, phase-separated, and transitional regimes. Macromolecules. 29 no. 22 (1996) 7155-7163. 

Spiro JG, Parinha IPS, Winnik MA (2003) Thermodynamics and morphology of latex blend films. Macromolecules 36(20) 7791-7802. doi 10.1021/ma021579j... 

P2 Peticolas, W.L., Kubasek, W.L., Thomas, G.A., Tsuboi, M. Biological Applications of Raman Spectroscopy Vol. 1 - Raman spectra and the Conformations of Biological Macromolecules, Spiro, T.G. (ed.). New York John Wiley and Sons 1987, p. 81. 

The photochromic reaction involves the reversible conversion of the zwit-terionic merocyanine (sample kept in the dark) to the uncharged spiro form (sample exposed to lights the isomerization is thus accompanied by large variations of the electrostatic interactions among the side chains of the polypept ides. Intrachain interactions should produce loops in the macromolecules, whereas intermolecular stacking should produce aggregation phenomena. As... 

In the presence of methanol (> 10%) the equilibrium between the two colorless species IV and I (Figure 14.9) is shifted toward the neutral spiro structure I. In these conditions the folding-unfolding of the macromolecules is photocontrol-led by the isomerization of the photochromic units. In the dark, they are present as charged species, so the macromolecules adopt a disordered conformation. 

Exposure to light and the consequent photoconversion of the side chains to the apolar spiro form make the macromolecules adopt the oe-helix conformation. 

Spiro, J.G. et al. (2006) Experimental and theoretical investigation of the lamellar structure of a styrene-butyl methacrylate diblock copolymer by fluorescence resonance energy transfer, small-angle X-ray scattering, and self-consistent-field simulations. Macromolecules, 39 (20), 7055-7063. 

International Union of Pure and Applied Chemistry, Nomenclature of Regular Double-Strand (Ladder and Spiro) Organic Polymers (Recommendations 1993), PureAppL Chem., 65,1561-1580 (1993). International Union of Pure and Applied Chemistry, Structure-Based Nomenclature for Irregular Single-Strand Organic Polymers (Recommendations 1994), PureAppL Chem., 66,873-889 (1994). International Union of Pure and Applied Chemistry, Source-Based Nomenclature for Non-Linear Macromolecules and Macromolecular Assemblies (Recommendations 1997). PureAppL Chem., 69, 2511— 2521 (1997). 

Nafie LA and Zimba CG (1987) Raman optical activity and related techniques. In Spiro TG (ed) Biological Applications of Raman Spectroscopy, Vol 1, Raman Spectra and The Conformation of Biological Macromolecules, pp 307-343. New York John Wiley C Sons. 

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