Gold chloride cluster anions grow as zigzag chains
LDI-MS detects Au_nCl_{n+3}– anions whose lowest isomers are zigzag chains starting from AuCl4–, growing exergonically by about 41–44 kcal mol–1.
Source
Structures and growth pathways of Au<sub>n</sub>Cl<sub>n+3</sub><sup>-</sup> (n ≤ 7) cluster anions
Study at a glance
- Design
- Computational / modelling — LDI-TOF of HAuCl4 with global-search structures of Au_nCl_{n+3}– clusters
- N
- Gas-phase cluster mass spectrometry plus DFT — no sample N
- Population
- Gold chloride cluster anions Au_nCl_{n+3}–
- Outcome
- Lowest-energy structures and exergonic growth pathway R1
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Authors recorded matrix-free LDI-TOF mass spectra of HAuCl4 and globally searched Au_nCl_{n+3}– (n=2–4, then 5–7) at TPSSh/aug-cc-pVTZ/ECP60MDF.
What they found
AuCl4– is the strongest peak; Au_nCl_{n+1}–, Au_nCl_{n+3}– and Au_nCl_{n+5}– appear for n=1–4. Lowest Au_nCl_{n+3}– isomers share a zigzag skeleton; R1 growth is exergonic (ΔE −41 to −44 kcal mol–1).
The limits
What it doesn't show
No condensed-phase isolation of the clusters; n>4 isomers are computational extensions; LDI may not match Brust-Schiffrin solution intermediates.
Key terms
- LDI-MS
- Laser desorption/ionization mass spectrometry of gold chloride salts.
- Zigzag gold chloride chain
- Lowest-energy motif with a terminal Au(III)Cl4-like unit plus Au(I) links.
- Aurophilic interaction
- Closed-shell Au(I)···Au(I) attraction, here ~2.87–2.92 Å.
- NKCS search
- Global-minimum cluster search used before DFT refinement.
- TPSSh
- Hybrid DFT functional used with Stuttgart Au pseudopotentials.
Flashcards
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Quiz yourself
Dominant LDI anion:
Common questions
What is the most intense anion?
AuCl4–.
Shared structural motif?
Zigzag skeleton starting from AuCl4–.
Is growth thermodynamically downhill?
Yes, about −41 to −44 kcal mol–1 per AuCl addition.
Do Au(III)–Au(I) contacts show aurophilicity?
No; aurophilicity is between nearby Au(I) atoms.
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