Compounds with Multiple Hydrazide Groups

As the cychc hydrazide groups are the essential feature in luminol type chemiluminescence, the introduction of more than one of these structures in an appropriate aromatic system may increase the chemiluminescence quantum yield. 

However only one of the compounds of this type has as yet reached the efficiency of luminol, although the first representative of this series, pyromellitic hydrazide (7), described as early as 1937 [21], exhibits a rather strong yellow chemiluminescence. The maximum emission was found to be at 540 nm in a 

Mellitic acid trihydrazide (8) gives about 2,3% of the luminol chemiluminescence. It was synthesized (as its tris-hydrazinium salt) recently [23] 4,75, 

The fluorescence quantum yield of the corresponding tetramethylester (10) is ca. 80% of that of the double amount of the methyl 3-amino phthalate fluorescence . The relatively low chemiluminescence efficiency probably does not arise from a sort of internal concentration quenching but perhaps from an incomplete reaction of (9) with the oxidant. The compound will behave as a specially substituted phthalhydrazide, only one of the hydrazide Roupings reacting at any given moment. 

A similar discrepancy between the fluorescence efficiency of the amino-phthalic ester derivative and the chemiluminescence of its corresponding hydrazide was observed in the case of oligomers of 3-amino-6-vinyl phthalic esters and the hydrazide prepared from it. 

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