Synthesis and Crystal Structure of 1,4,7-Tris(2-mercaptoethyl)-1,4,7-triazacyclononane

The title compound, 1,4,7-tris(2-mercaptoethyl)-1,4,7-triazacyclononane (H3tmtacn), was synthesized and the crystal structure was determined by the single-crystal X-ray diffraction method at 293 K. It crystallizes in the monoclinic space group P21/n with a = 9.9553(13)Å, b = 13.7164(19)Å, c = 14.724(2)Å, β = 102.528(2)°, V = 1962.7(5)Å3, Dx = 1.355 g/cm3, and Z = 4. The R1 [I > 2σ(I)] and wR2 (all data) values are 0.0538 and 0.1436, respectively, for all 4528 independent reflections. The triazacyclononane moiety is protonated at the two nitrogen atoms with hydrogen-bonded chloride ions and water molecules as H3tmtacn·2HCl·H2O.