Heilbron complexes

Herbstein, F. H., Structural parsimony and structural variety among inclusion complexes (with particular reference to the inclusion-compounds of trimesic acid, N-(para-tolyl)-tetrachlorophthalimide, and the Heilbron complexes). Top. Curr. Chem. 1987,140, 107-139. 

Molecular Inclusion Compounds of E, -l-[p-Dimethylamino-phenyl]-5-[o-hydroxyphenyl]-penta-l,4-dien-3-one (DHDK) — the Heilbron Complexes ... 

Nevertheless, rimunaging about in the older literature might also be a promising doorway to rediscover new clathrate formers (e.g. o-tetraphenylene and developmental possibilities of known lattice hosts [cf tri-o-thymotide (7) trimesic acid Heilbron complexes etc.] are full of surprises. 

The reaction of a-aminonitriles and carbon disulphide was stated by Cook and Heilbron to give 5-amino-2-mercaptothiazoles however, they later found that the same reaction with aminoacetonitrile was more complex. When aminoacetonitrile sulphate in ethanolic solution was treated with carbon disulphide, the dithiodicarbamate 9 was formed. Benzylation was then carried out treatment of the resulting ester 10 with phosphorus tribromide with subsequent loss of water gave 5-amino-2-benzylthiothiazole 11 in a quantitative fashion. The rapid reaction was thought to be the first example of the formation of a 5-aminothiazole from an a-aminoamide. 

In 1921 Heilbron and Buck reported that DHDK (5) forms rather stable molecular complexes with 15 different guests whose chemical identities ranged from chloroform through phenanthrene (an electron donor) to 2,4,6-trinitrotoluene (TNT, an electron acceptor) (Table 7). The colours were reported to range from yellow to black, suggesting a variety of types of interaction between the components. Further-... 

Table 7. The list of guests which were reported to form molecular complexes with DHDK, according to the original study of Heilbron and Buck...

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