Dithieno phospholes

Two types of symmetric fused dithienophospholes exist, which differ according to the position of the S atoms as illustrated by compounds (53) [54] and (54) [50] (Scheme 15). The a A -dithieno[3,2-fo 2, 3 -d]phosphole (55) has recently been considered as a potential subunit for the construction of n-conjugated materials [55] (Scheme 15). Exploitation of the reactivity of the nucleophilic P-atom of (55) allows access to derivatives (56) and complexes (57) (Scheme 15). The absorption and emission behaviour of these species varies with the nature of the P-moieties. Upon oxidation of the P-centre of (55),bathochromic shifts of Ajnax Aejn were observed Aj ax 344 nm for (55) and ca. 373 nm for (56), and Agjn 422 nm for (55) and ca. 460 nm for (56) [55]. These results nicely illustrate... 

The dithieno[3,2-6 2, 3 -<7 phosphole 63 has been designed as a very sensitive material for detection of fluoride ions <06OL495>. Cationic dithieno[3,2-6 2, 3 -<7 phospholes alkylated at the phosphorus atom have also been prepared for application as building blocks... 

The phosphole ring can be fused to a number of other cyclic structures. The most widely found are the dibenzo- and dithieno-derivatives 9 and 10. It is noteworthy that these compounds display few properties associated with phospholes. Instead, they behave as diarylphosphines due to the presence of the highly aromatic fused benzene or thiophene rings. 

Table 20 Photophysical data for dithieno[3,2-fa 2, 3 -d]phosphole derivatives (Amax and Aem in nm, quantum yieid <1> determined using quinine sulfate as standard)...

Recent advances in the synthesis of benzothiophenes 12THC(29)347. Synthesis and apphcations of highly luminescent dithieno[3,2- 2, 3T((] phospholes 13SL920. 

Synthesis and appftcations of h hly luminescent dithieno[3,2-6 2, 3 -d phospholes 13SL920. 

T. Neumann, Y. Dienes and T. Baumgartner, Highly sensitive sensory materials for fluoride ions based on the dithieno[3,2-fc 2, 3 -d]phosphole system, Org. Lett., 8, 495-497 (2006). 

Dienes Y, Durben S, Karpati T, Neumann T, Englert U, Nyulaszi L, Baumgaitner T (2007) Selective tuning of the band gap of pi-conjugated dithieno[3,2-b 2, 3 -d]phospholes toward different emission colors. Chem Eur J 13 7487... 

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