Molecular gold strings: aurophilicity, luminescence and structure–property correlations

Abstract

Different external stimuli can affect the molecular structure of molecular gold strings, influencing their physical properties.

Synthesis, structural and photophysical properties of dimethylphosphino(perfluoro-)phenylene-based gold(i) dimers

“…[47][48][49] It is meanwhile broadly accepted thatin the absence of other energetically near lying states like found in thiolate or alkyne complexesthe origin of light emission is a 3 [(dσ*) 1 (pσ) 1 ] excited state, which is populated by the excitation of an electron from an antibonding to a bonding σ-MO (dσ/dσ*-MOs are formed from the fully occupied d z 2-orbitals of adjacent Au atoms). [50][51][52][53][54] This means that in the excited state the attractive interactions between the gold atoms are significantly strengthened which leads to a considerable shortening of the Au-Au distancesan effect observed in both, experiments and calculations. 55,56 A huge distortion is always accompanied by a huge Stokes shift which is one of the characteristics of phosphorescence based on aurophilic interactions.…”

Crystal engineering of aurophilic supramolecular architectures and coordination polymers based on butterfly-like copper–dicyanoaurate complexes: vapochromism, P–T behaviour and multi-metallic cocrystal formation

“…[14][15][16][17][18][19][20][21][22][23][24][25][26][27] However, a systematic investigation of dicyanoaurate-based bimetallic molecular complexes that aggregate only by means of aurophilic interactions has not yet been performed, although the study of molecular gold strings of other gold(I) complexes is well developed. 28 In a previous publication, we reported a series of molecular complexes of Zn(II) with these characteristics, and we demonstrated their preformation in solution at concentrations where no aurophilic interactions are present. 29 The formation of {(L) 2 Zn[Au(CN) 2 ]} + (L = chelating ligand) is favoured with respect to [Zn(L) 3 ] + due to the great difference between K 2 and K 3 formation constants for Zn(II) complexes (see Fig.…”

Bi- and trinuclear coinage metal complexes of a PNNP ligand featuring metallophilic interactions and an unusual charge separation

“…The term "metallophilic" interactions was first introduced by Pyykkö in 1994 3 and has since then been established for the description of short distances between closed shell metal centres with distances often below the sum of their van der Waals radii. [23][24][25][26][27][28][29][30][31][32][33][34][35] While aurophilic and argentophilic attractions fall in the range of strong hydrogen bonds (30-50 kJ mol −1 ), cuprophilic contacts are considered to be approximately three times weaker (up to 15 kJ mol −1 ). [36][37][38][39] Despite intensive research, aspects of these attractions are still under debate.…”