Synthesis, proton NMR and electronic absorption spectra, and halochromic properties of bis(2-methyl-1-phenyl-3-isoindolyl)(het)arylmethane dyes was written by Naef, R.. And the article was included in Dyes and Pigments in 1985.SDS of cas: 3012-80-4 This article mentions the following:
Several bis(2-methyl-1-phenyl-3-isoindolyl)(het)arylmethane perchlorate dye salts were synthesized, the (het)aryl substituent representing the acceptor systems 2-benzothiazolyl, 1-methyl-2-benzimidazolyl, 4-quinolyl, 4- and 2-pyridyl as well as Ph. The constitution of these green dye salts was supported by their 1H-NMR spectra. The variation of the electronic absorption maximum of this dye series was in accord with theor. considerations based on SCF-CI and PMO calculations They give rise to the statement that the bathochromic effect of the varied (het)aryl group is essentially due to a LUMO-LUMO interaction with the diisoindolylmethane cyanine moiety, i.e., a second-order perturbation, enlarging the bathochromic shift caused by the increased twist angles inflicted on the central bonds by the bulkiness of the (het)aryl substituents (a first-order perturbation). The halochromic properties of these dyes are explicable on the same basis. The dissociation constants pK* and pKR+* were measured and compared with analogous diindolyl- and diindolizinylhetarylmethane dyes, showing little difference with regard to the former and the distinct sequence indolizinyl > indolyl > isoindolyl dye series for the latter. In the experiment, the researchers used many compounds, for example, 1-Methyl-1H-benzo[d]imidazole-2-carbaldehyde (cas: 3012-80-4SDS of cas: 3012-80-4).
1-Methyl-1H-benzo[d]imidazole-2-carbaldehyde (cas: 3012-80-4) belongs to imidazole derivatives. Imidazole is a heterocyclic compound with a five-membered planar ring. It is amphoteric and highly polar. Many drugs contain an imidazole ring, such as certain antifungal drugs, the nitroimidazole series of antibiotics, and the sedative midazolam.SDS of cas: 3012-80-4
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem