Soluble Adamantyl‐Substituted Oligothiophenes with Short Fluorescence Decay: An Approach for Ultrafast Optical Signal Processing

Abstract

THF-soluble, adamantyl-substituted oligothiophenes (n = 1-3) were prepared via Negishic ross-coupling reactions. Thus, the synthesis of 2-(1-adamantyl)quaterthiophene was realized by cross-couplingo f5 -bromo-2''-(1-adamantyl)terthiophene with 2-thienylzinc chloride. Treatment of these oligothiophenes with FeCl 3 affords the corresponding dimeric compounds, whichh ave pigmentp roperties. In contrast, the mono-substituted (1-adamantyl)oligothiophenes (n = 1-4) are readily soluble in organic solvents. Par-ticularly the quarter-oligomerd isplays remarkable optical properties such as an increased Stokes's hift in combination with av ery fast fluorescenced ecay of 0.39 ns and ah igh fluorescenceq uantum yield. The compound was incorporated in as olid poly(methylm ethacrylate)m atrix and its optical properties were nearly unaltered. This may allow applications in high-throughput opticals ignal processing exceeding the GBit scale.[a] Dr.

Terminal Terthiophenediones: Fast-Decay Fluorescent Dyes and Their Efficient Syntheses

“…As a consequence, carbonyl derivatives without enolizable hydrogen atoms (compare ref ) in the α-position are attractive. We targeted 1,1′-[(2,2′:5′,2″-terthiophene)-5,5″-diyl]­bis­(2,2-dimethylpropan-1-one) ( 2a ) fulfilling all conditions where the terminal tert -butyl groups are expected to be favorable concerning the solubility and minimizing the tendency of aggregation (compare ref ).…”

“…We targeted 1,1′-[(2,2′:5′,2″-terthiophene)-5,5″-diyl]bis(2,2-dimethylpropan-1-one) (2a) fulfilling all conditions where the terminal tert-butyl groups 6 are expected to be favorable concerning the solubility and minimizing the tendency of aggregation (compare ref 25). Positions 3 and 4 in the thiophene units of 2a were left unsubstituted in order to provide molecular dynamics 25 (see below).…”

“…Positions 3 and 4 in the thiophene units of 2a were left unsubstituted in order to provide molecular dynamics (see below).…”

Fluorescence and fluorescent dyes

“…Equation (10) can be applied in many cases, preferment for series of similar compounds, however, there are exceptions. Short fluorescent lifetimes τ 0 are expected for strongly light-absorbing dyes with comparably broad absorption bands such as 1 where 4 ns were observed; however, the weaker light absorbing diketoterthiophenes unexpectedly exhibit an appreciably shorter fluorescence lifetime [29] of only 0.4 ns. Moreover, the fluorescence lifetime τ 0 according to eq.…”

Synthesis and Applications of Asymmetric Catalysis Using Chiral Ligands Containing Quinoline Motifs

“…Treatment of (+)-camphor 100 with Tf 2 NPh in THF at 0 °C produced the desired compound 101 in 90% yield (Scheme 21 ). The chiral camphor triflate 101 efficiently underwent a Pd-catalyzed Negishi cross-coupling reaction with the quinoline organozinc reagent, 88` b c d affording the desired 2-alkenylquinoline 102 in acceptable yield. Subsequent hydrophosphination with Ph 2 P(O)H, in the presence of a catalytic amount of t -BuOK (20 mol%) in DMSO provided phosphine oxide 103 (Scheme 21 ).…”