Novel NLO-phores containing dihexyl amino benzo[b]thiophene exhibiting good transparency and enhanced electro-optical activity

Abstract

Two new chromophores (A and B) were synthesized, in which a benzo [b]thiophene moiety was first introduced as a donor group. To investigate the macroscopic EO activity of the new chromophores, guest-host doped polymer films were fabricated by doping chromophores A and B into amorphous polycarbonate (APC). The poled films containing A with a loading density of 20 wt% achieved a maximum EO coefficient (r 33 ) of 42 pm V À1 at 1310 nm, while for the poled films containing B, the r 33 value is 75 pm V À1 at 1310 nm. UV-vis spectral absorption of the new chromophores were studied in solutions and films, and chromophores A and B showed a maximum absorption in chloroform of 658 nm and 688 nm, respectively. Compared to the FTC (r 33 ¼ 20-50 pm V À1 at 1310 nm, l max ¼ 685 nm in chloroform) analogues, they exhibited enhanced electro-optical activity together with a high optical gap.This new type of chromophore provided better optimization of the nonlinearity-transparency trade-off.

Exposed N and S Active Sites: An Indicator for Oxygen Reduction on Metal‐Free Yam‐Derived Porous Carbons

“…The series of NSDC catalysts, different with C800, exhibit the type‐IV of N 2 adsorption/desorption isotherms with high surface areas and pore volumes (Figure a–b, Table S1), which suggest the important role of the salt‐mixtures in forming porous structure. Specifically, for NSDC800, the specific surface area and pore volume are 964 m 2 g −1 and 1.12 cm 3 g −1 , respectively, higher than these of NSDC700, NSDC900, and C800 (Figure a‐c and Table S1), which could be beneficial for exposing active sites and thereof enhancing the catalytic activity . The pore size distribution curves for NSDC800 and NSDC900 indicate the majority mesopore size is ca.…”

“…Biomass becomes attractive as the qualified precursor for the large‐scale preparation of carbons due to the advantages of cheap, available in high quality, and renewable as well as rich in heteroatoms dopants (N, S, P, etc.) . In recent developments, biomass‐derived N‐doped carbons represent a unique building block in electrocatalytic ORR, but most of their activities are at a great distance for the commercial Pt/C as the insufficient exposed active sites ,.…”

“…It not only increases the type and amount of active sites, but also tunes the electronic properties and delocalization of the surface atoms and thereof boosting the ORR performance. Some efforts were made by using extrinsic N resources such as ammonia to increase the amount of active sites for keratin‐ and water hyacinth‐derived carbons, which demonstrate the excellent ORR activity, respectively ,. Additionally, it is learnt that a porous structure is necessary for high‐active catalysts, as it can maximize the electroactive surface area and active sites, provide multi‐dimensional electron and mass transport paths, and also reduce the diffusion effect ,.…”

“…In addition to the merits above, other factors that favor the ORR performance of carbons should be also considered simultaneously: (i) high specific surface area, (ii) well‐balanced pore size distribution, (iii) high graphitization degree, and (iv) good wettability ,,,. Therefore, the desired metal‐free biomass‐derived porous carbons should have a feasible preparation process as well as the above‐mentioned merits.…”

Synthesis of Unsymmetric Monosubstituted and Disubstituted Dinaphthothiophenes

“…First, 2‐bromothiophene was coupled with a trans‐2‐(4‐Phenyl)vinylboronic acid using a Suzuki–Miyaura coupling to create compound 15 in 76% yield . The 5‐position of the thiophene ring was then formylated using n ‐butyllithium and DMF, giving compound 16 in 36% yield . The 5‐position is preferentially formylated because of its relatively low pK a (~33) compared with the three or four positions (~39) resulting from its location next to the sulfur in the thiophene ring .…”