Syntheses, crystal structures, hirshfeld surface analyses and electrochemical etoposide/camptotechin sensor applications of acetaldehyde oxime derivatives

Abstract

(E)-2-(4-Hydroxyphenyl)-2-oxoacetaldehyde oxime monohydrate (I) and (E)-2-(4-Nitrophenyl)-2-oxoacetaldehyde oximes (II) were synthesized from 4′-hydroxyacetophenone and 4′-nitroacetophenone, respectively. Their structures were elucidated by elemental analyses, 1H NMR, UV–Vis and also their molecular and crystal structures were determined by single crystal X-ray analysis. They belong to monoclinic system P 21/n space group with a = 6.8198 (3) Å, b = 7.3846 (3) Å, c = 16.4706 (5) Å, β = 94.300 (3)°, Z = 4 and V = 827.15 (6) Å3 (for I) and a = 7.1557 (3) Å, b = 14.5338 (5) Å, c = 8.6311 (3) Å, β = 108.321 (3)°, Z = 4 and V = 852.13 (5) Å3 (for II). Hirshfeld surface analyses of the crystal structures indicate that the most important contributions for the crystal packings are from H•••H (35.0%) and H•••O/O•••H (33.9%) contacts (for I) and H•••O/O•••H (40.9%) and H•••H (19.4%) contacts (for II). Hydrogen bonding and van der Waals contacts are the dominant interactions in the crystal packings. Comparing the limit of detection achieved in this work with the therapeutic ranges of etoposide/camptotechin verifies the possibility of using both oxime I and II based electrodes as sensors. However GCPE/I electrode exhibited the best electrochemical improvement on the etoposide determination in terms of both sensitivity and limit of detection