Synthesis and characterization of dirhodium(II,II) formamidinate complexes containing short-bite nitrogen ligands was written by Tresoldi, Giuseppe;Lo Schiavo, Sandra;Nicolo, Francesco;Cardiano, Paola;Piraino, Pasquale. And the article was included in Inorganica Chimica Acta in 2003.Formula: C7H5N3 This article mentions the following:
The Rh4+2 complex [Rh2(form)2(O2CCF3)2(H2O)2] (form = N,N’-di-p-tolylformamidinate anion) easily reacts with the short-bite ligand pyrido[2,3-b]pyrazine, molar ratio 1:2, yielding [Rh2(form)2(pyrido[2,3-b]pyrazine)2(O2CCF3)2] which was characterized by conductivity measurements and IR and 1H NMR spectroscopy. The complex exhibits a lantern type structure with the two N ligands coordinated, in a cisoid arrangement, at the equatorial positions across the dirhodium unit while the axial sites are occupied by two monoligated trifluoroacetate groups. Conductivity and IR data show that in DMSO the complex undergoes dissociation of both the axial ligands leading to [Rh2(form)2(pyrido[2,3-b]pyrazine)2(DMSO)2]2+. The parent compound reacts also with 2-chloro-5,7-dimethyl-1,8-naphthyridine and 2,7-dichloro-5-methyl-1,8-naphthyridine leading to [Rh2(form)2(O2CCF3)(C10H9N2O)(H2O)] and [Rh2(form)2(O2CCF3)(C9H6N2ClO)(H2O)], resp., in which the dirhodium unit is supported by three different bridging ligands. Microanal., 1H NMR and x-ray data unambiguously show that the reaction proceeds, unexpectedly, with elimination of a trifluoroacetate group and the substitution of a Cl atom of the naphthyridine ligands by O. In the experiment, the researchers used many compounds, for example, Pyrido[2,3-b]pyrazine (cas: 322-46-3Formula: C7H5N3).
Pyrido[2,3-b]pyrazine (cas: 322-46-3) belongs to pyrazine derivatives. Pyrazine has the elements of symmetry for the point group D2h. It has three mutually perpendicular two-fold axes. It also has three mutually perpendicular planes of symmetry. As a result, pyrazine also has a centre of symmetry. A large number of pyrazine derivatives are known for their antitumor, antibiotic, anticonvulsant, antituberculosis, and diuretic activities.Formula: C7H5N3