Inorganic Chemistry Exam 4

Lets go Exam 4 100 100 100

Why are halogen atoms (Cl·, Br·, I·) considered electronically equivalent to Co(CO)₄·?

Both are one electron short of a closed shell (7-e⁻ vs 17-e⁻).

What analogous reactions do Cl· and Co(CO)₄· both undergo?

Dimerization (Cl₂, [Co(CO)₄]₂).

What type of acid is HCo(CO)₄ in water?

Strong acid (like HCl).

Pseudohalogen

A molecule or anion that behaves chemically like a halogen or halide, even though it is not a true halogen element.

What main-group species is electronically equivalent to Fe(CO)₄?

S (sulfur).

What does “isolobal” mean?

Fragments with similar frontier orbitals: number, symmetry, shape, and occupancy.

. What organic fragment is isolobal with Fe(CO)₄?

CH.

Why are CH₃ and Mn(CO)₅ able to form dimers?

they both have one frontier orbital with one electron → form σ-bonds upon overlap.

Why do Cl· and (CO)₅Mn· have similar reactivity?

Similar frontier orbital shape, symmetry, energy (basis for isolobality).

How do Cl· and (CO)₅Mn· each achieve closed-shell configurations?

Concept:

• Gain an electron → Cl⁻, [(CO)₅Mn]⁻

• Dimerize → Cl₂, Mn–Mn carbonyl dimer

Why do isoelectronic species show parallel reactions?

Concept: Closed-shell drive (octet or 18-electron rule).

What does the isolobal analogy allow you to predict?

Allowed connectivities and analogous bonding patterns (e.g., CH₃ ↔ Mn(CO)₅).

What reaction parallels are expected between isolobal species?

Concept:

• Dimerization

• Addition to unsaturated bonds

• Acid/base analogies

• Ligand substitution patterns

What is the maximum possible metal–metal bond order?

Quintuple (fivefold).

Which orbitals form a quintuple bond?

: σ, 2π, 2δ bonding interactions.

How many skeletal electron pairs does closo-[B₆H₆]²⁻ have?

7 pairs.

What structure corresponds to: cluster electrons = vertices + 1?

nido (nestlike).

What structure corresponds to: electrons = vertices + 2?

arachno (weblike).

What do Wade’s rules predict?

Polyhedral shape from number of skeletal electron pairs.

How do you compute cluster contribution of Fe(CO)₃?

8 (Fe) + 6 (CO) − 12 = 2 electrons.