1,8-bis(2-hydroxy-3,5-di-tert-butylbenzyl)-4,11-dibenzyl-1,4,8,11-tetraazacyclotetradecane

Abstract

A cyclam (1,4,8,11-tetraazacyclotetradecane)-based macrocycle bearing two benzyl and two 2-hydroxy-3,5-di-tert-butylbenzyl pendent arms was synthesized and characterized using spectroscopic techniques and single crystal X-ray diffraction. The macrocycle crystallizes in the triclinic space group P-1, with the asymmetric unit containing one-half of the molecule. The structure is stabilized by hydrogen-bonding which exists between the phenolic protons and the nitrogen atoms of the macrocyclic ring. The presence of this hydrogen bonding is observed in the 1 H-NMR due to the deshielded nature of the phenolic OH peak (δ 9.99). Cyclic voltammetry of the ligand revealed a single quasi-reversible peak at −0.58 V (E pc = −0.48 V and E pa = −0.68 V), which is due to the electrochemical oxidation of the phenol to the phenoxyl radical.

Dicyclohexylammonium O,O’-Diphenyl Phosphate, [(C6H11)2NH2][(C6H5O)2P(O)(O)]: Spectroscopic Study, Crystal Structure, and Hirshfeld Surface Analysis

“…The relatively high negative value is attributed to shielding caused by the negative charge on the oxygen atom. In the 1 H NMR, the signal at 8.80 ppm corresponds to the NH 2 protons, and the downfield chemical shift is due to the hydrogen bonding effect, similar to the one that was reported for a compound exhibiting hydrogen bonding in the X-ray structure [37]. The aliphatic and aromatic protons appear within 1.01 to 2.97 ppm and 7.02 to 7.28 ppm, as expected.…”