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 migration of amines in platinum(II) complexes, published in 1978-08-31, which mentions a compound: 15227-42-6, Name is cis-Dichlorobis(pyridine)platinum(II), Molecular C10H10Cl2N2Pt, Product Details of 15227-42-6.
Derivatog. data indicate that the 1st stage of the thermal conversion of (LH)2[PtCl4] (L = NH3, MeNH2, piperidine, pyridine, γ-picoline, PhNH2, p-toluidine, 8-hydroxyquinoline, quinoline) or (enH2)[PtCl4] is the cleavage of HCl and the formation of PtL2Cl2. All the complexes studied fall into 2 groups according to the temperature of the beginning of the process: (1) complexes with a temperature for the start of thermal reaction at 180 – 200° contain amines the basicity constants of which are >10-5 and (2) complexes with decomposition temperatures at 130-50° contain amines the basicity constants of which are <10-8. Compounds in my other articles are similar to this one(cis-Dichlorobis(pyridine)platinum(II))Product Details of 15227-42-6, you can compare them to see their pros and cons in some ways,such as convenient, effective and so on.
Reference:
Tetrahydroisoquinoline – Wikipedia,
1,2,3,4-Tetrahydroisoquinoline | C9H11N – PubChem