Dimethylaminophenyl group

A different approach for the modification of the basic Malachite Green lactone structure has been the replacement of one 4-dimethylaminophenyl group by electron-rich heterocycles. The most thoroughly investigated heterocycle has been the 3-indolyl residue, which may be introduced by two different routes as shown in Scheme 7. 

Fig. 20. Two series of donor-acceptor polyconjugated molecules bearing a benzodithia or a dimethylaminophenyl group as donor D and a variety of acceptor groups A.

The presence of a 4-(4-dimethylaminophenyl) group enhances the visible absorption differences between the pyrylium and thiopyrylium salt analogues. Thus, on reaction of 625 with hydrosulfide ion a change in hue from magenta (540 nm) to blue (580 nm) is observed this color change serves as the basis for a new chemodosimeter selective for hydrosulfide (Scheme 240) <2003JA9000>. 

Organon have developed Org 31710 and Org 33628 (Figure 7.2). Org 31710 has the same substituent at position 11 but differs at the 17-position, where it contains a spiro-ether group. In the B-ring, it has a 6P-methyl group. Org 33628 has a acetophenone group instead of a dimethylaminophenyl group and is combined with a methylene-furan substituent at position 17 [12]. 

Another interesting point arises from a comparison between If and Ig. A substitution of a phenyl group by a p-dimethylaminophenyl group in the 5-position has a large influence on the S—S bond length in I. 

The nature of the side-group also has a considerable effect on the thermal stability of polyorganosiloxanes polymers containing a methyl group are the most thermally stable when the p-dimethylaminophenyl groups are stable. Crosslinked and ladder organosilicon polymers are characterised by high thermal stability [1]. 

Table 19 Photovoltaic performance of DSSCs 4-dimethylaminophenyl group modified D moiety...

Three types of experiments have been applied to the study of diffusion controlled cyclization of polymers. These are excimer formation in polymers containing pyrene groups at both chain ends [Py-polymer-Py ], exciplex formation in polymers containing a pyrene at one end and a dimethylaminophenyl group at the other [DMA polymer-Py i ], and triplet-triplet [TT] annihilation between anthracene groups at both ends of a polymer [A -polymer-A 3]. A fourth obvious approach, as yet to be reported, is intramolecular phosphorescence quenching in a polymer... 

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