title: 6-Chloro-3-(3-methyl-phen-yl)-1,2,4-triazolo[4,3-b]pyridazine.
abstract: The title compound, C(12)H(9)ClN(4), was prepared from dichloro-pyridazine and tolyl-tetra-zole in a nucleophilic biaryl coupling followed by thermal ring transformation. The mol-ecule is essentially planar (r.m.s. deviation for all non-H atoms = 0.036 Å) and an intra-molecular C-H⋯N hydrogen bond occurs. In the crystal, the mol-ecules form dimers connected via π-π inter-actions [centroid-centroid distance = 3.699 (2) Å], which are further connected to neighbouring mol-ecules via C-H-N bonds. The bond lengths in the pyridazine ring system indicate a strong localization of the double bonds and there is a weak C-Cl bond [1.732 (3) Å].
authors: University Mainz, Duesbergweg 10-14, 55099 Mainz,  Germany.
authors: Jasmin
authors: J
authors: Preis
authors: Dieter
authors: D
authors: Schollmeyer
authors: Heiner
authors: H
authors: Detert