A trigonal coordination of Au(I) phosphane complexes stabilized by O–H⋯X (X = Cl–, Br–, I–) interactions

Abstract

In this work, we show that intramolecular hydrogen bonding can be used to stabilize tri-coordinated phosphane-gold(I) complexes. Two molecular structures of 2-(diphenylphosphino)benzoic acid (L) coordinated to a gold(I) atom were determined by single-crystal X-ray diffraction. The linear L–Au–Br shows a standard linear coordination and dimerizes via hydrogen bonds of the carboxylic acid. Upon addition of two additional phosphane ligands the complex [L3Au]X is formed which is stabilized by three intramolecular –C(O)O–H…X hydrogen bonds as proven by the X-ray structure of the respective chlorido-complex. X-ray powder diffractograms suggest the same structure also for X– = Br– and I–. Graphic abstract

Mechanochemical preparation of strongly emissive monosubstituted triarylphosphane gold(i) compounds activated by hydrogen bonding driven aggregations

“…The Full Width at Half Maximum (FWHM) goes from less than ten Hertz for complex 8 (10 Hz) or 9 (2 Hz), to hundreds of Hertz for complex 6 (160 Hz) (see Table 1S in the ESI †). The dynamic behaviour of bis-phosphine compounds 4-9 can be attributed to different counterion coordination options, 38,39 ranging from the ionic to the three coordinate limits according to the following equilibrium [(PR 3 ) 2 AuCl] % [(PR 3 ) 2 Au] + + Cl − , rather than to equilibria leading to the formation of tris-or tetra-phosphine compounds, since for the latter the thermodynamic constants of formation are generally very small. As quoted in the literature, 40 a trend of binding ability of the anions can be depicted from the analysis of FWHM of compounds 4-9 as follows: Cl − > OTf − > PF 6 − > BAr 4 − .…”

Post-synthesis heating, a key step to tune the LPR band of gold nanorods covered with CTAB or embedded in a silica shell

“…Indeed, for this reason, and to efficiently employ AuNRs in specific applications, such as photothermal therapy, it is crucial to protect them from heat-induced shape deformation. In this regard, several methods were adopted to increase the stability of the core particles when applying heating, and in particular, enclosing AuNRs in a thick silica shell has been revealed to be a valid approach [35,[51][52][53].…”