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Carcerands template effects

A cap molecule of suitable size and symmetry could effectively close off the interior of trimer 7 to create a very large molecular container. Such a feat has recently been accomplished in our laboratories, where trimer carceplex 9 -3 DMF was synthesized in 37% yield, by reaction of trimer 7 with 2,4,6-tris(bromomethyl)mesitylene under basic conditions (Scheme 4-4) [21]. No empty trimer carcerand has yet been isolated, which implies that a template (or templates) is required for formation. Can a large single template molecule form trimer carceplex 9-guest We are currently investigating this possibility. Such an investigation begs the question when does a template effect become a solvent effect ... [Pg.110]

Carcerand 51 is much more soluble than 50 due to eight 2-phenylethyl substituents [41], During its synthesis a template effect by various solvent molecules was observed. Thus cyclizing the precursor in dimethyl sulfoxide, dimethyl acetamide, and dimethyl formamide gave the corresponding carceplexes 51 G in 61%, 54%, and 49% yields, respectively (i.e. the interior of the carcerands was occupied by one solvent molecule). [Pg.193]

Again, this effect can be understood in terms of the templating of hyperbolic structures, due to the presence of hyperbolic TFS, set up by the caesium ions in solution. For example, the carcerand molecule resides on the P-surface (Fig. 2.21), which is a common TFS in aqueous zeolite syntheses. The improved yield of large ring compoimds in the presence of cesium is also understandable on this basis, since the precursors to these compounds prefer to wrap around tunnels of the TFS [13]. [Pg.344]


See other pages where Carcerands template effects is mentioned: [Pg.407]    [Pg.103]    [Pg.416]    [Pg.1428]    [Pg.373]    [Pg.190]    [Pg.1352]    [Pg.250]    [Pg.407]    [Pg.409]    [Pg.10]    [Pg.13]    [Pg.373]    [Pg.375]    [Pg.88]   
See also in sourсe #XX -- [ Pg.373 ]

See also in sourсe #XX -- [ Pg.373 ]




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