Synthesis and spectral characterization of cyclotriphosphazene based 18-membered macrocycles

New 18-membered cyclotriphosphazene-containing macrocycles 7-10 were obtained by 1 + 1 condensation reaction of [dispiro-N3P3(C12H8O2)2((N(Me)NCH)2 N4C20H26)] (2) with N,N′-dimethyl-ethylenediamine-1,4-diyldimethylenebis(4-methyl-2-formylphenol) (3), N,N′-dimethyl-ethylenediamine-1,4-diyldimethylenebis(4,5-dimethyl-2-formylphenol) (4), N,N′-dimethyl-ethylenediamine-1,4-diyldimethylenebis(5-chloro-2-formylphenol) (5) and N,N′-dimethyl-ethylenediamine-1,4-diyldimethylenebis(5-bromo-2-formylphenol) (6), respectively.