Equivalent and Complement of the -Bonding Model and Charge-Shift Bonding Model: A Natural Bond Orbital/Natural Resonance Theory/Atoms in Molecules Investigation via Cu/Ag/Au Bonding in BMX (B = H₂O, H₂S, NH₃, and PH₃; M = Cu, Ag, and Au; and X = F, Cl, Br, and I)

Chemical bonding is the languageof logic for chemists.Two newresonance bonding models, omega-bonding and charge-shift (CS) bonding,are gaining popularity among chemists. This study investigated theCu/Ag/Au bonding in BMX (B = H2O, H2S, NH3, and PH3; M = Cu, Ag, and Au; and X = F, Cl, Br,and I) complexes using natural bond orbital (NBO) analysis, naturalresonance theory (NRT), and atoms in molecules (AIM) method. The mainaim is to reveal the relation between omega-bonding model and CSbonding model via Cu/Ag/Au bonding. Our studies demonstrate that theCu/Ag/Au bonds exhibit the characteristics of both omega-bondingand CS bonding. Further studies found that omega-bonding and CSbonding models are equivalent and complement each other in understandingthe studied Cu/Ag/Au bonding. Another interesting finding is the implicationof the omega symbol in the omega-bonding model. These findings couldhelp to promote the communication and CS bonding understanding ofmany more similar omega-bonded complexes.