Unsupported Au(i)⋯Cu(i) interactions: influence of nitrile ligands and aurophilicity on the structure and luminescence

Abstract

The synthesis, structural characterization and the study of the photophysical properties of complexes [AuCu(C6F5)2(N[triple bond]C-CH3)2] 1, [AuCu(C6F5)2(N[triple bond]C-Ph)2]2 2, and [AuCu(C6F5)2(N[triple bond]C-CH=CH-Ph)2] 3 have been carried out. The crystal structures of complexes 1-3 consist of dinuclear Au-Cu units built from mediated metallophilic Au(I)...Cu(I) interactions. In the case of complex 2 two dinuclear units interact via an aurophilic interaction leading to a tetranuclear Cu-Au-Au-Cu arrangement. Complex 2 is brightly luminescent in solid state at room temperature and at 77 K with a lifetime in the nanoseconds range, while complexes 1 and 3 do not display luminescence under the same conditions. The presence of the aurophilic interaction in complex 2 seems to be responsible for the blue luminescence observed. DFT and time-dependent DFT calculations agree with the experimental results and support the idea that the origin of the luminescence of these complexes arise from orbitals located in the interacting metals.

Structural characterization of dinuclear gold(I) diphosphine complexes with anion-triggered luminescence

“…The thermochromic luminescence is expected to be the result of molecular structure rigidification along with thermal contraction of the crystal lattice, which also alters the extent of the noncovalent interactions [14,23,40]. The blue shift of the emission spectrum with decreasing temperature, however, can be explained by the presence of short aurophilic contacts, which cannot shorten more significantly upon cooling [23,40]. The mononuclear complex 5 exhibits intriguing thermochromic luminescence properties (Table 7).…”

A Dinuclear Gold(I)–Silver(I) Derivative of 2‐Cyclopentylidene‐2‐sulfanylacetic Acid and Related Complexes: Synthesis, Crystal Structures, Properties and Antitumor Activity

“…One such property is luminescence, which has the potential to enable investigations into the intracellular distribution of gold complexes, as highlighted recently 5. This property was identified in compounds in which a gold–gold (aurophilic) interaction6,7 is present and also in compounds where metal centres other than gold can establish gold–metal (metallophilic) interactions 8,9. These interactions have been studied in compounds in which the two metals have a direct interaction (i.e.…”

Coinage Metal Complexes of Bis‐Alkynyl‐Functionalized N‐Heterocyclic Carbenes: Reactivity, Photophysical Properties, and Quantum Chemical Investigations

“…Complex 9 crystallizes in the orthorhombic space group Pbcn with half am olecule in the asymmetric unit (Figure5). Whereast hese intermetallic distances are similart ot hose in [AuCu(C 6 F 5 ) 2 (NC-Ph) 2 ] 2 , [71] furthere xamples of unsupported AuÀCu interactions in this fashion are rather scarce. Each Cu I ion is coordinated by two bromide ions in an almostl inear fashion (Br-Cu-Br' 165.2 and 175.08)w ith CuÀBr bond lengths between 2.175(13)a nd 2.240 (14) .A dditionally,b oth Cu ions bind to one gold ion Au1 with CuÀAu distances of 2.773 and 2.835 .…”