Recently, we observed that the De of the HfX (X = O, S, Se, Te, Po) series decreases moving from lighter HfO to heavier HfPo, which correlates with the binding elements' electronegativity (i.e., O > S > Se > Te > Po). Building upon our prior work, we also analyze the HfCX (X = O, S, Se, Te, Po) series. Because the metal-binding atom C is the same for all HfCX, it is somewhat difficult to make a prediction on the De trend for the HfCX series based on our knowledge on HfX series. Indeed, we observe a reversed trend for HfCX, where De increases moving from lighter HfCO to heavier HfCPo. This opposite trend does follow expectations based on the dipole moment (μ) of the ligand (i.e., CO < CS < CSe < CTe < CPo). The relationship between De(Hf-CX) vs. μ(CX) is linear with R 2 = 0.991 (Figure ). To confirm the generality of this relationship, at the same level of theory we computed the De of the isovalent ZrCX and TiCX series and related it to the dipole moment of the CX species. Note that the ground states of ZrCO and TiCO are both 5 Δ. For both metals (M = Zr and Ti ), the De increases moving from MCO to MCPo and importantly the near-linear De vs. μ relationship is preserved (R 2 values 0.992 and 0.995, Figure ). Notably, the slope of the relationship decreases moving from HfCX to TiCX by about 25%. This can be rationalized by the fact that a decrease of De was observed moving from HfCX to TiCX, while the dipole moments are necessarily unchanged.