1,5-Diisocyanonaphthalene (DIN) is an aromatic diisocyanide (isonitrile) in which two âÂÂNâ¡C groups occupy the 1- and 5-positions of the naphthalene ring. The compound is also named 1,5-naphthalenediyldiisocyanide and has the molecular formula and relative molar mass 178.19 g/mol. It has been studied as a photophysical probe and as a lead compound for antifungal research.
Isocyanides feature the âÂÂNâ¡C functional group (often depicted as âÂÂN<sup>+</sup>â¡C<sup>âÂÂ</sup> â âÂÂN=C:), bonded to the aromatic ring through nitrogen. DIN's two isocyanide substituents make it a rigid, weakly polar ÃÂ-system. Photophysically, DIN shows limited solvatochromism compared with mono-formamido/mono-isocyano analogues (e.g., ICNF), but it forms notable ÃÂ-complexes with aromatic solvents that modulate emission, enabling discrimination among aromatics by fluorescence.
1,5-Diisocyanonaphthalene can be obtained by converting 1,5-diaminonaphthalene to the corresponding N,-diformamide, followed by dehydration (e.g., with phosphorus oxychloride in the presence of base). Reaction conditions and solvent choice influence outcome for this system.
Fluorescence/analytical: DIN's emission responds to specific ÃÂâÂÂàinteractions in aromatic solvents, suggesting use in distinguishing aromatic hydrocarbons optically; related hydrolysis-derived ICNF is a strongly solvatochromic dye.
In standardized CLSI broth microdilution tests against three Aspergillus fumigatus strains (MYA 3627, ATCC 204305 and Af293), 1,5-diisocyanonaphthalene showed the lowest MIC values among the tested isocyano-naphthalene derivatives, namely 0.6 üg/mL (3.4 üM) for all strains. Practical use may be limited by poor aqueous solubility; a related dimethylamino analogue (DIMICAN) progressed to in-vivo evaluation in a murine aspergillosis model.