Structural and fluorescence properties of 2-naphthylamine substituted cyclotriphosphazenes

•The 2-naphthylamino substituted cyclotriphosphazenes were synthesized and characterized.•Fluorescence properties of these compounds (3–8) were investigated.•The fluorescence quantum yield (ΦF) values of all compounds (3–8) were also determined.•All 2-naphthylamino substituted cyclotriphosphazene compounds were fully characterized.

The reactions of hexachlorocyclotriphosphazene, N3P3Cl6 (trimer) (1), with 2-naphthylamine (2) in tetrahydrofuran solution were studied and six new 2-naphthylamine substituted cyclotriphosphazene compounds (3–8) were obtained in this study. All of these compounds were fully characterized by elemental analyses, MALDI-TOF mass spectrometry, 1H, 13C, 31P NMR, electronic absorption and fluorescence spectroscopies. The molecular structure of compounds; mono- (3), geminal bis (4) and tetrakis (6) 2-naphthylaminocyclotriphosphazenes were also determined by X-ray crystallography. The fluorescence properties of newly synthesized compounds (3–8) were investigated and compared in tetrahydrofuran solution. The fluorescence quantum yield (ΦF) values of newly synthesized 2-naphthylamine substituted cyclotriphosphazenes (3–8) were also determined and compared in this solution.

Graphical abstractIn this study, 2-naphthylamino substituted cyclotriphosphazenes were synthesized and characterized. All 2-naphthylamino substituted cyclotriphosphazene compounds were fully characterized by elemental analysis, MALDI-TOF mass spectrometry, 1H, 13C, 31P NMR, X-ray (for compounds 3, 4, 6), electronic absorption and fluorescence spectroscopies. The fluorescence properties of newly synthesized 2-naphthylamino substituted cyclotriphosphazene compounds (3–8) were investigated and compared in tetrahydrofuran solution.Figure optionsDownload full-size imageDownload as PowerPoint slide