Conformational Study for Ionic Aggregates of Poly(oxyethylene) Dodecyl Ethers with Ferric-Thiocyanate Anion through the Intermediary of Potassium Ion

Copper thiocyanato complexes and cocaine – a case of ‘black cocaine’

“…Raman spectra and powder X-ray diffraction (PXRD) experiments clearly show that graphite is the source of the black colour; in the red acetone extract corresponding signals of graphite are absent. Thus, the acetone-soluble material contains Cu 2+ and Fe 3+ ions, SCN À and CocH + which strongly reminds to the above mentioned procedures for the extraction and detection of cocaine and related atropine bases using anionic thiocyanate metal complexes such as [Cr(SCN) 6 ] 3À , [Fe(NCS) 6 ] 3À , [3,5,6] [Fe(NCS) 4 ] À , [11] [Co(SCN) 4 ] 2À , [2,4,6] [Ni(SCN) 4 ] 2À , [6] but also [BiI 4 ] À (Dragendorff reagent), [6] or [AuCl 4 ] À . [26,27] The anionic complexes form tight ion-pairs with the protonated atropine bases (or related molecules), allowing the selective liquid-liquid extraction using organic solvents.…”

“…[62] While in H 2 O only the three species [Fe (NCS) x (H 2 O) 6Àx ] m+ with x = 1 to 3 (m = 3Àx) were discussed, [62] in other solvents such as N,N-dimethylacetamide (DMA) all species [Fe(NCS) x ] y with x = 1 to 6 (À3 < y < +3) have been previously assigned. [11,12,63] Since the species [Fe(NCS) x (H 2 O) 6Àx ] m+ with x = 1 to 3 are reported to be well soluble in water, we can assume that during the preparation of the original black material in water, in the presence of excess SCN À anionic species [Fe(NCS) x ] nÀ (x = 4-6; n = 1-3) were formed and precipitate as ion pairs with CocH + . [11,12,15] Thus, in the acetone extract the same species were expected.…”

“…[11,12,63] Since the species [Fe(NCS) x (H 2 O) 6Àx ] m+ with x = 1 to 3 are reported to be well soluble in water, we can assume that during the preparation of the original black material in water, in the presence of excess SCN À anionic species [Fe(NCS) x ] nÀ (x = 4-6; n = 1-3) were formed and precipitate as ion pairs with CocH + . [11,12,15] Thus, in the acetone extract the same species were expected. The solvatochromic longwavelength band of the Fe/SCN species observed in the samples #4 (Figure 7) seems to be largely identical to the 492 nm band of the acetone extract, while the 363 nm cannot be assigned to Fe/SCN species and probably resulting from Cu I /SCN complexes.…”

“…On the other hand it is well known that anionic transition metal complexes formed from SCN − and metal ions such as Fe 3+ , Co 2+ , Cu 2+ , Hg 2+ can form ion pairs with protonated nitrogen bases such as the alkaloids cocaine or atropine thus enabling liquid(water)‐liquid(organics) extraction methods for isolation and detection of these bases . Related liquid‐liquid extraction (LLE) was also reported for the recovery and detection of metal ions by using SCN − and suitable (large, organic) cations . At the same time the binding of the metal cations to cocaine base in such black powder might modify essential properties of cocaine such as solubility or hamper detection.…”

“…[2][3][4][5][6][7][8][9] Related liquid-liquid extraction (LLE) was also reported for the recovery and detection of metal ions by using SCN À and suitable (large, organic) cations. [10][11][12][13][14][15] At the same time the binding of the metal cations to cocaine base in such black powder [16][17][18] might modify essential properties of cocaine such as solubility or hamper detection.…”