Terphenyl-4-thiol

Comparison between two thiol (-SH) terminated molecules as the 1,1 4, 1 -terphenyl-4-thiol (TFT) and the analogous molecule after substitution of carbon with nitrogen in the ring, 6-(5-pyridin-2,yl-pyrazin-2-yl)pyridine-3-thiol (PPPT) have been investigated by NEXAFS spectroscopy [17] (Fig. 4.8). 

As an example, starting from m-terphenyls with other functionalities in 2 -position, other concave molecules with a m-terphenyl core are conceivable. Sulfur substituents have already been introduced into the 2 -position of a m-terphenyl, for instance X = SH, SOjH or SO2CI (see Section 6). A protected thiol functionality has already been incorporated into a concave thiol acetate 42 [28] (Scheme 7). 

In the thiol 79 and the sulfinic acid 80, two new acidic functionalities are now present in the 2 -position of a m-terphenyl system and should be incorporable into concave structures by a double bridging of the m-terphenyl. For the acetyl-protected thiol 78, the corresponding concave thiol acetate 42 (Scheme 7) could be obtained after tetrabromination of the four methyl groups and bridging with m-phenylenedithiol (see Sect. 2.3). 

The locus of the thiol and benzylic halide functionalities can be reversed thus tetrakis-mercaptomethyl-m-terphenyl (90) [9] can be coupled with bis-... 

Liining. U. Baumgartner. H. Concave reagents. 13 2 -Substituted m-terphenyls as building blocks. Synthesis of a concave thiol acetate. Synlett 1993. 571-572. 

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