Crystal and molecular structure of 5,5'-azobis-3-bromo-4-[5-(5-chloro-3-methyl-1-phenylpyrazol-4-yl)-1H-1,2,4-triazol-3-yl]-1H-pyrazole

The x-ray structure is solved for the potentially hexadentate podand Ph-(Me)Pz(Cl)-HTz-HPz(Br)-N=N-HPz(Br)-HTz-(Cl)Pz(Me)-Ph, which crystallizes with four dimethylacetamide solvent molecules (Pz = pyrazole, Tz = triazole). The middle part of the centrosymmetric molecule is practically planar whereas the Ph-fragment is inclined at 46°. The protonated N atoms of the HPz- and HTz-rings are involved in H-bonds to the O atom of a C 4 NOH 9 solvent molecule. The two coplanar 11-membered systems so formed have the common fragment C(HPz)-N=N'-C'(HPz). The nature of the bond delocalization in the molecule is discussed