In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Thermal isomerization of complex platinum(II) compounds, published in 1972, which mentions a compound: 15227-42-6, Name is cis-Dichlorobis(pyridine)platinum(II), Molecular C10H10Cl2N2Pt, Computed Properties of C10H10Cl2N2Pt.
The thermal cis-trans isomerization of [PtA2I2] complexes, where A = NH3, MeNH2, EtNH2, pyridine, was studied by derivatography. The heat of isomerization is 1-7 kcal/mole. trans-[Pt(R2SO)ACl2]-type complexes melt upon heating and isomerize in the melt. The isomerization reaction proceeds through formation of a tetrahedral intermediate.
Although many compounds look similar to this compound(15227-42-6)Computed Properties of C10H10Cl2N2Pt, numerous studies have shown that this compound(SMILES:[Cl-][Pt+2]([N]1=CC=CC=C1)([Cl-])[N]2=CC=CC=C2), has unique advantages. If you want to know more about similar compounds, you can read my other articles.
Reference:
Tetrahydroisoquinoline – Wikipedia,
1,2,3,4-Tetrahydroisoquinoline | C9H11N – PubChem