The solvothermal reaction of CuSCN with 1,2-bis(diphenylphosphino)ethane (dppe) yielded a coordination polymer, which was characterized to be a complex of CuCN and 1,2-bis(diphenylthiophosphinyl)ethane (dppeS₂): [(CuCN)₂(dppeS₂)]_n (1). The identification of complex 1 reveals that CuSCN was decomposed and the sulfur was transferred to dppe, and represents a new example of the transformation of inorganic sulfur to organic sulfur. The weak coordination interactions between CuCN and dppeS₂ indicate that dppeS₂ may be substituted by ligands with strong coordination ability. The ligand 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tpt) was chosen as a substitute ligand. Three novel CuCN coordination polymers of tpt were synthesized and characterized: [Cu₂(CN)₂(tpt)]_n (2) with a 3-D (10,3)-a network, [Cu₂(CN)₂(tpt)]_n (3) and [Cu₂(SCN)(CN)(tpt)]_n (4) both with a 2-D (6,3) network, and only complex 2 can be obtained from CuCN directly. Interestingly, compounds 2 and 3 are genuine high-dimensional supramolecular isomers. During the syntheses of 2–4, single crystals of dppeS₂ were isolated, which indicates it was substituted by tpt ligand and also confirmed the transformation of sulfur from CuSCN to dppe. The transformation of sulfur can be observed only when the temperature is relative high (>160 °C). At 140 °C, complex 5 containing only CuSCN was attained and no dppeS₂ has been monitored in the resulting filtrate.