Oligomers with a Tetrasubstituted Biaryl Core

In the synthesis of the swivel-cruciform binaphthyl-based oligomers 27 and 28, bromination of commercially available l,l -binaphthol followed by a Williamson reaction gives binaphthyl ethers with various alkoxy groups [43], The dibromi- 

Based on the perception that interchain interactions should be suppressed by introducing nonplanar units into the PFO chains, we decided to prepare random copolymers incorporating swivel-cruciform binaphthyl moieties into the polymer backbone [46], Furthermore, as shown in the previous examples on low molecular weight chromophores by Bazan and coworkers, the distorted nature of the binaphthyl unit should simultaneously facilitate the formation of a glassy, amorphous state. PFO and random copolymers 34, incorporating binaphthyl units, 

The thermal properties of the swivel cruciforms 40-47 were analyzed by DSC. Remarkably, the cruciforms 45, 43, 44 (R = tat-butyl), 46 and 42 show distinctly increased Tg values of 95, 130, 140, 130 and 225 °C, respectively. Only the fluori-nated derivatives 45 and 46 display clear melting transitions in DSC with Tm = 228 and 257 °C, respectively. 

Hence we synthesized a related swivel-cruciform dimer 49 with dithienyl-phe-nylene-dithienyl arms by a synthetic strategy similar to the already described oh- 

OFETs with wet-deposited films of 48 as the active layer in bottom contact geometry were fabricated on highly doped n-type silicon wafers with the organic semiconductor layer (ca. 50 nm) deposited from chloroform solution [70], OFETs made from 48 exhibited negative amplification, which is typical of 

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