In this paper wereport the first systematicnonlinear optical study of molecules with octopolarchargedistribution. First hyperpolarizabilities were determined by the Hyper-Rayleigh Scattering technique and depolarization of the harmonic scattered light was measured and linked to the symmetry of the scatterers. It is shown experimentally that octopolar molecules have nonlinear optical properties that compare favorably to those of their dipolar counterparts. The hyperpolarizability of octopolar molecules is shown to be solvent independent, in contrast to the hyperpolarizability of dipolar systems.

Chiral poly(3-(3,7-dimethyloctyloxy)thiophene)s were prepared using three different methodologies, rendering polymers with different degrees of regioregularity. In a first attempt, 3alkoxythiophene was polymerized using FeCl 3 , resulting in a highly regioirregular poly(3alkoxythiophene).Secondly, the GRIM methodology was applied, which yielded poly(3alkoxythiophene)s with relatively high, but not perfect, degrees of regioregularity. Finally, an alternative methodology was used, which consisted of the exclusive formation and subsequent 2 polymerization of 2-bromomagnesio-3-(3,7-dimethyloctyloxy)-5-bromothiophene) and which resulted in poly(3-alkoxythiophene)s with (almost) perfect regioregularity. The degrees of regioregularity were evaluated with 1 H NMR, UV-Vis and CD spectroscopy and cyclic voltammetry. These (regioregular) poly(3-alkoxythiophene)s show a very high λ max , indicating very high conjugation lengths. Moreover, the polymers could easily be oxidized and they were stable in both neutral as well as oxidized state.This stability can be correlated with the decrease in oxidation potential. The reproducibility and reversibility of the oxidation was demonstrated by UV-Vis spectroscopy. Finally, the chiral properties of the polymers were investigated with circular dichroism spectroscopy. These experiments demonstrated again the difference in regioregularity of the polymers.

In this article we discuss the state of the art in the field of second‐order non‐linear optical polymers. More specifically, we highlight those results that we think made an important contribution to the field, combined with some of our own results. We start with a general overview of all the aspects involved in characterizing second‐order non‐linear optical polymers, from thin film formation and poling to second‐harmonic generation and electro‐optic measurements on such systems. Next, we review the second‐order non‐linear optical properties of selected polymer systems such as poly(vinyl ether)s, polystyrenes, polymethacrylates, main‐chain polymers and high Tg polymers like polyimides and polymaleimides. Finally, we discuss some new polymer systems that might become important in the field of non‐linear optics in the near future.

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Results published so far show that azo-polymer-based colonic drug targeting is still in its infancy. It seems that microbial degradation of the investigated azo polymers is slow, and to date, no system is capable of delivering drugs completely and reproducibly within less than 6 h after entering the colon when the azo bond is located in the main chain,