Abstract:
In this study, we comment on recently published papers in the Journal of Materials Science: Materials in Electronics, reporting on the growth of bulk crystals. Prolonged exposure to air during the slow evaporation solution growth process of the following aromatic amine based crystals viz. "p-aminoazobenzene" (also known as aniline yellow) (1) [J Mater Sci: Mater Electron 32 20698-20709 (2021)], "4-aminopyridine-1-ium 4-aminobenzoate" (2) [ibid 32 22342-22361 (2021)], "N-benzyl-3-nitroaniline" (3) [ibid 32 26318-26328 (2021); 34 1895 (2023)], "bis(4-acetylanilinium) tetrachloridozincate" (4) [ibid 32 11,393-11,417 (2021)], "sodium sulfanilate dihydrate" (5) [ibid 30 2224-2234 (2019)], "(E)-N'-[4-(dimethylamino) benzylidene]-4-hydroxybenzohydrazide hemihydrate" (6) [ibid 30 2638-2646 (2019)], "anilinium perchlorate" (7) [ibid 29 5718-5725 (2018)] and "p-toluidinium perchlorate" (8) [ibid 35 1586 (2024)] results in their surface deterioration. The yellow "lithium d-isoascorbate monohydrate" (9), "potassium l-ascorbate monohydrate" (9a) [J Mater Sci: Mater Electron 34 825 (2023); ibid 35 1585 (2024)], yellow "l-ascorbic acid" (10) [ibid 32 8174-8182 (2021); ibid 34 143 (2023)] are examples of surface degraded crystals based on ascorbic acid. Optical properties of surface degraded materials are unreliable. Use of freshly prepared starting reagents and an oxygen-free atmosphere are essential requirements for the growth of bulk crystals of air-sensitive materials, in pure form.
