Abstract
RECENT work1-5 has shown that gold-based ligands in compounds of carbon and nitrogen can induce novel molecular structures with coordination numbers at C and N as high as 5 and 6. These phenomena must be ascribed to metal-metal interactions (Au...Au), which can overrule bonding in classical configurations. Here we describe a study of the molecular structures of tetra(auro)ammonium ((LAu)4N+) and tetra(auro)arsonium ((LAu)4As+) cations (where L is a ligand). We find that the classical tetrahedral structure in these four-coordinate compounds is abandoned in favour of a square-pyramidal geometry once the radius of the central element is too large to allow for metal-metal bonding in a tetrahedral geometry. Thus, whereas the nitrogen compounds adopt a tetrahedral structure, for the larger arsenic atom an arsenic-capped square of gold atoms represents a more favourable core geometry. We have not yet been able to prepare the intermediate phosphorus compound, but we expect it also to have the square-pyramidal structure.
Original language | English |
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Pages (from-to) | 141-143 |
Number of pages | 3 |
Journal | Nature |
Volume | 352 |
Issue number | 6331 |
DOIs | |
State | Published - 1991 |
Externally published | Yes |