Molecules 1999, 4(1), 28-51; doi:10.3390/40100028
Article

Polarization by the effect of a small torsional change in the benzothiazole (A)-benzobisthiazole (B) oligomer A-B13-A

Received: 30 September 1998; Accepted: 5 January 1999 / Published: 12 February 1999
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: We use a method for the calculation of the molecular dipole ( μ ) and quadrupole (θ ) moments and dipole-dipole (α ), dipole-quadrupole ( A) and quadrupole-quadrupole (C ) polarizabilities which we have successfully applied to the benzothiazole (A)-benzobisthiazole (B) linear oligomer A-B13-A. Two model rotational isomers have been characterized: (1) the fully-planar (000) conformation; and (2) a rotational isomer with each unit rotated in the range 1 - 10° in the same direction (+++). For isomer 000, μ is smaller than for +++. The calculation of α, A and C has been carried out by the interacting induced dipoles polarization model that calculates tensor effective anisotropic point polarizabilities (method of Applequist et al.). The values of A are specially sensitive to μ which varies under rotation. This fact explains the great values of Ax,xx for the +++ polar isomer. It is found that small torsional changes can enhance solubility by a clear increasing of the hydrophilic accessible surface area. However, the torsion of the oligomer varies the value of μ and so modifies α, C , and, specially, A. For conformer +++, polarization effects occur even when each unit is rotated only f = 1°. The observed effect is an increase in μ and, hence, in α , C , and, specially, A.
Keywords: multipole moments; polarization; polarizability; geometric descriptors; fractal dimension
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MDPI and ACS Style

Torrens, F.; Sánchez-Marín, J.; Nebot-Gil, I. Polarization by the effect of a small torsional change in the benzothiazole (A)-benzobisthiazole (B) oligomer A-B13-A. Molecules 1999, 4, 28-51.

AMA Style

Torrens F, Sánchez-Marín J, Nebot-Gil I. Polarization by the effect of a small torsional change in the benzothiazole (A)-benzobisthiazole (B) oligomer A-B13-A. Molecules. 1999; 4(1):28-51.

Chicago/Turabian Style

Torrens, Francisco; Sánchez-Marín, José; Nebot-Gil, Ignacio. 1999. "Polarization by the effect of a small torsional change in the benzothiazole (A)-benzobisthiazole (B) oligomer A-B13-A." Molecules 4, no. 1: 28-51.

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