Aminotriazines as Locking Fragments in Macrocyclic Synthesis

The macrocyclic compounds (6-(4‘,6‘-diamino-1‘,3‘,5‘-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II)
triperchlorate dihydrate, [Cu(HL2)](ClO4)3·2H2O, (6-(6‘-amino-4‘-oxo-1‘H-1‘,3‘,5‘-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II) diperchlorate hydrate, [CuL3](ClO4)2·H2O, and [(6-(4‘,6‘-dioxo-1‘H-1‘,3‘,5‘-triazinyl)-1,4,6,8,11-pentaazacyclotetradecane)copper(II)] diperchlorate, [CuL4](ClO4)2, have been synthesized. The
macrocycles synthesized contain respectively pendant melamine, ammeline, and ammelide rings. The X-ray
cyrstallographic analyses of [Cu(HL2)](ClO4)3·2H2O, triclinic, space group P1̄, a = 9.489(10) Å, b = 12.340(2)
Å, c = 24.496(4) Å, α = 87.74(10)°, β = 85.51(10)°, γ = 70.95(10)°, and Z = 4, and {[CuL3](ClO4)2·H2O}2,
monoclinic, space group C2/c, a = 18.624(8) Å, b = 17.160(2) Å, c = 15.998(6) Å, β = 117.82(2)°, and Z =
4, are reported. The structure of [Cu(HL2)](ClO4)3·2H2O shows the formation of linear tapes, formed by a
combination of hydrogen bonds and π-π stacking interactions. The structure of [CuL3](ClO4)2·H2O displays
formation of dimers, formed by a coordinate bond from the oxygen in one molecule to the copper atom of another.
The tautomeric forms of the ammeline and ammelide moieties have been determined. The potential of these
compounds as subunits for cocrystallization has been investigated.