High Yield Synthesis and Preliminary Spectroscopic Study of Mono-N-alkylated Cyclen Derivatives of Salicylic Acid

Structure and Conformational Studies of Aza‐Crown 8‐Amino‐BODIPY Derivatives: Influence of Steric Hindrance on Their Photophysical Properties

“…[9] Column chromatography was performed on silica gel. 1 H (300 MHz) and 13 C NMR spectra were recorded with a Bruker AV 300 spectrometer. Chemical shifts are reported in parts per million (ppm), calibrated to the solvent peak set.…”

“…As expected, the equilibrium between the cyanine form and its corresponding complex is also observed in the aliphatic region of the NMR spectra [12] even though no changes in the indacene moiety are pro- duced. [13] This fact is probably due to the conformation of the system, which places the indacene perpendicular to the cyclen ring and, thus, far from the cation.…”

“…1 H NMR (300 MHz, CD 3 CN): δ = 8.63 (s, 1 H), 7.59 (s, 1 H), 7.38 (s, 2 H), 7.32 (d, J = 3.5 Hz, 1 H), 6.56 (s, 1 H), 6.42 (s, 1 H), 4.30 (ddd, J = 11.2, 7.8, 3.9 Hz, 1 H), 4.09-3.99 (m, 2 H), 3.90-3.51 (m, 18 H) ppm. 13 13…”