Work

Bis( N , N -diethyl-4-methyl-4-piperazine-1-carboxamide) tetrakis(isothiocyanato-κ N )cobalt(II), a model compound for the blue color developed in the Scott test

Year: 2023

Type: article

Abstract: The complex, bis( N , N -diethyl-4-methyl-4-piperazine-1-carboxamide) tetrakis(isothiocyanato-κ N )cobalt(II) ( N , N -diethyl-4-methyl-4-piperazine-1-carboxamide = diethylcarbamazine), (C 10 H 22 N 3 O) 2 [Co(NCS) 4 ], is presented. This complex is a blue precipitate, insoluble in water but soluble in organic solvents, that is formed from the reaction of diethylcarbamazine citrate, a protonated tertiary amine, with cobalt(II) and thiocyanate. This reaction, in the form of the Scott test, is a common presumptive test for cocaine hydrochloride. The known cobalt compound, [K 2 Co(NCS) 4 ]·3H 2 O, has a deep-blue coloration due to the tetrahedral [Co(NCS) 4 ] 2− that is also present in the ion pair with bulky amines, and is similar to the color of other tetrahedral cobalt(II) complex ions, such as [CoCl 4 ] 2− . The structure is consistent with a previous proposal that a hydrophobic ion pair formed between [Co(NCS) 4 ] 2− and two protonated molecules of cocaine is responsible for the blue hydrophobic products formed by cocaine in the Scott test.

Source: Acta Crystallographica Section E Crystallographic Communications

DOI: 10.1107/s2056989023000981

Authors: Allen G. Oliver, Tracy-Lynn E. Lockwood, Jessica Zinna, Marya Lieberman

Institution: University of Notre Dame

Language: English

Topic: Crystal structures of chemical compounds

Subfield: Inorganic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $500

Funder: Army Research Office