Bank Security Dye Packs: Synthesis, Isolation, and Characterization of Chlorinated Products of Bleached 1‐(methylamino)anthraquinone

Abstract

Banknote evidence is often submitted after a suspect has attempted to disguise or remove red dye stain that has been released because of an anti-theft device that activates after banknotes have been unlawfully removed from bank premises. Three chlorinated compounds have been synthesized as forensic chemical standards to indicate bank security dye bleaching as a suspect's intentional method for masking a robbery involving dye pack release on banknotes. A novel, facile synthetic method to provide three chlorinated derivatives of 1-(methylamino)anthraquinone (MAAQ) is presented. The synthetic route involved Ultra Clorox bleach as the chlorine source, iron chloride as the catalyst, and MAAQ as the starting material and resulted in a three-component product mixture. Two mono-chlorinated isomers (2-chloro-1-(methylamino)anthraquinone and 4-chloro-1-(methylamino)anthraquinone) and one di-chlorinated compound (2,4-dichloro-1-(methylamino)anthraquinone) of the MAAQ parent molecule were detected by gas chromatography mass spectrometry (GC-MS), and subsequently isolated by liquid chromatography (LC) with postcolumn fraction collection. Although GC-MS is sensitive enough to detect all of the chlorinated products, it is not definitive enough to identify the structural isomers. Liquid-state nuclear magnetic resonance (NMR) spectroscopy was utilized to elucidate structurally the ortho- and para-mono-chlorinated isomers once enough material was properly isolated. A reaction mechanism involving iron is proposed to explain the presence of chlorinated MAAQ species on stolen banknotes after attempted bleaching.

Development and validation of AccuTOF-DART™ as a screening method for analysis of bank security device and pepper spray components

“…The device also contains a remote activation system which causes the device to explode moments after being removed from the bank. The money is rendered useless when coated with the red dye, and the robber is similarly stained and somewhat incapacitated by the tear gas [1][2][3][4][5][6]. The combination of MAAQ and CS is unique to these security packs, often making the identification of these chemicals essential to the case [3,6].…”

First and Second Reductions in an Aprotic Solvent: Comparing Computational and Experimental One-electron Reduction Potentials for 345 Quinones

“…35 Quinones have also been used in applications ranging from energy storage, 36,37 natural dyes (e.g., 2hydroxy-1,4-naphthoquinone, or Henna), 29,[38][39][40] and synthetic dyes (e.g., Disperse Red 9, or 1-(methylamino)-anthraquinone, used in bank security dye packs that get activated upon bank robberies). 41 Most computations apply a thermodynamic cycle to compute redox potentials. 17 There are several important ingredients for such calculations to be accurate.…”

First and Second Reductions in an Aprotic Solvent: Comparing Computational and Experimental One-Electron Reduction Potentials for 345 Quinones

“…The quinones range in size from 12 to 153 atoms and include several substituents including alkyl chains, halogens, polar protic and aprotic groups, and even charged groups such as sulfonates. The data set includes quinone derivatives such as adriamacyin and cerubidine, which are clinically approved drugs for treating cancer, − natural dyes such as 2-hydroxy-1,4-naphthoquinone (henna), and synthetic dyes such as disperse red 9 and 1-(methylamino)-anthraquinone, which is used in bank security dye packs that get activated upon bank robberies …”

“…The data set includes quinone derivatives such as adriamacyin and cerubidine, which are clinically approved drugs for treating cancer, 40−42 natural dyes such as 2-hydroxy-1,4-naphthoquinone (henna), 43 and synthetic dyes such as disperse red 9 and 1-(methylamino)-anthraquinone, which is used in bank security dye packs that get activated upon bank robberies. 44 Having a large data set from a single source reduces the likelihood of random errors associated with different equipment and human error. The aprotic solvent conditions in which the experiments were carried out simplify calculations since they mitigate proton transfer with the solvent but also pose a challenge to some continuum solvation models that typically do not perform as well for low dielectric constants as for aqueous solvation.…”