What is synergic bonding?
Beginner
A A two-way electron exchange between metal and ligand
B A one-way donation from ligand to metal only
C A hydrogen bonding interaction in carbonyls
D A purely ionic attraction between metal and ligand
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A two-way electron exchange between metal and ligand
Synergic bonding involves σ donation from metal to ligand and π back-donation from metal d-orbitals to ligand π* orbitals, so it is a two-way exchange.
In the diagram, the σ bond arrow points from:
Beginner
A Oxygen of CO to the metal M
B Metal M to the carbon of CO
C Carbon of CO to the metal M
D Metal M to the oxygen of CO
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Metal M to the carbon of CO
The σ bond arrow goes from M to C, meaning the metal donates σ electron density to the carbon of CO.
Which orbitals of CO accept π back-donation from the metal?
Beginner
A The σ* 2pz orbital only
B π 2px* and π 2py* antibonding orbitals
C σ 2pz bonding orbitals
D The lone pair orbitals on carbon
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π 2px* and π 2py* antibonding orbitals
The diagram shows π back-bonds from metal d-orbitals into the π 2px* and π 2py* antibonding orbitals of CO.
Which ligands are named as forming synergic bonds with metals?
Beginner
A CH₄, C₂H₄, and C₂H₂
B CO, CN⁻, and NO
C O₂, N₂, and F₂
D H₂O, NH₃, and Cl⁻
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CO, CN⁻, and NO
The source names CO, CN⁻, and NO as the classic synergic ligands because they have accessible π* orbitals.