No abstract

In this work, our group synthesized and characterized a fully conjugated graft polymer comprising of a donor–acceptor molecular backbone and regioregular poly­(3-hexylthiophene) (RRP3HT) side chains. Here, our macromonomer (MM) was synthesized via Kumada catalyst transfer polycondensation reaction based on ditin-benzodithiophene (BDT) initiator. The tin content of MM was then investigated by inductively coupled plasma-mass spectrometry (ICP-MS), which allowed for accurate control of donor/acceptor monomer ratio of 1:1 for the following Stille coupling polymerization toward our graft polymer (BP). The structures of the polymers were then characterized by gel permeation chromatography (GPC), NMR, and elemental analysis. This was followed by the characterization of optical, electrochemical, and physical properties. The magneto-optical activity of graft polymer BP was then measured. It was found that, despite the presence of the acceptor backbone, the characteristic large Faraday rotation of RRP3HT was maintained in polymer BP, which exhibited a Verdet constant of 2.39 ± 0.57 (104) °/T·m.

A donor−acceptor conjugated copolymer containing thienothiophene (donor) units and Co(II) complexes (acceptor) has been synthesized and characterized. The studies of magnetic properties of the polymers by SQUID and EPR measurements showed antiferromagnetic exchange interaction between neighboring spin centers along with the polymer backbone through intrachain interactions. It is the first time that the D−A conjugated polymer backbone serves as bridging ligands for magnetic couplings, making these type of polymers promising as magnetic materials. Moreover, the magneto-optical activity of polymer LCP1 was characterized using magnetic circular dichroism spectroscopy. It was found that the material exhibits a large magneto-optic rotation with a peak Verdet constant of 2980 deg•T −1 •m −1 at 590 nm.

We have prepared a series of complexes of the type [Ir III (ppy) 2 (L] n+ complexes (1−4), where ppy is a substituted 2phenylpyridine and L is a chelating phosphine thioether ligand. The parent complex (1) comprises an unsubstituted phenylpyridine ligand, whereas complex 2 contains a nitro substituent on the pyridine ring, complex 3 features a diphenylamine group on the phenyl ring, and 4 has both nitro and diphenylamine groups. Crystallographic, 1 H NMR, and elemental analysis data are consistent with each of the chemical formulae. DFT (density functional theory) computational results show a complicated electronic structure with contributions from Ir, ppy, and the PS ligand. Ultrafast pump−probe data show strong contributions from the phenylpyridine moieties as well as strong panchromatic excited state absorption transitions. The data show that nitro and/or diphenylamine substituents dominate the spectroscopy of this series of compounds.