5,8-Bis[bis(pyridin-2-yl)amino]-1,3,4,6,7,9,9b-heptaazaphenalen-2(1H)-one dimethyl sulfoxide monosolvate dihydrate

Abstract

In the asymmetric unit of the title compound, C26H17N13O·C2H6OS·2H2O, there is one independent hepta­zine-based main mol­ecule, one dimethyl sulfoxide mol­ecule and two water mol­ecules as solvents. The tri-s-triazine unit is substituted with two dipyridyl amine moieties and a carbonylic O atom. As indicated by the bond lengths in this acid unit of the hepta­zine derivative [C=O = 1.213 (2) Å, while the adjacent C—N(H) bond = 1.405 (2) Å] it is best described by the keto form. The cyameluric nucleus is close to planar (r.m.s. deviation = 0.061 Å) and the pyridine rings are inclined to its mean plane by dihedral angles varying from 47.47 (5) to 70.22 (5)°. The host and guest mol­ecules are connected via N—H⋯O, O—H⋯O and O—H⋯N hydrogen bonds, forming a four-membered inversion dimer-like arrangement enclosing an R 4 4(24) ring motif. These arrangements stack along [1-10] with a weak π–π inter­action [inter-centroid distance = 3.8721 (12) Å] involving adjacent pyridine rings. There are also C—H⋯N and C—H⋯O hydrogen bonds and C—H⋯π inter­actions present within the host mol­ecule and linking inversion-related mol­ecules, forming a three-dimensional structure.

State of the Art in the Preparation and Properties of Molecular Monomeric s-Heptazines: Syntheses, Characteristics, and Functional Applications

“…Previously, Kroke's group published the first two asymmetrically substituted s-heptazines, a diaminochloro-s-heptazine 56 and a bis(pyridine)amino derivative of cyameluric acid, which was obtained by hydrolysis of the corresponding asymmetrical monochloro-s-heptazine (Chart 1). 57 It has been shown earlier that s-heptazine derivatives with substituents containing additional donor atoms can be used as ligands for mono-and multinuclear coordination compounds, with many examples of cyamelurates and melonates containing anionic ligands (Figure 1). More recently, an interesting trinuclear copper(II) complex 58 was obtained with a functionalized multidentate N-ligand tris(di-2-pyridylamino)-s-heptazine, which was obtained from cyameluric chloride (8) and the Scheme 3.…”