Synthesis, Structures, and Excited‐State Geometries of Alkynylgold(I) Complexes

Abstract

A series of phosphane‐ and (N‐heterocyclic carbene)gold(I) complexes were prepared by deprotonation of terminal alkyne precursors and reaction with the corresponding gold(I) chlorides. Some ten new compounds are reported; these are characterized by multinuclear NMR, optical spectroscopy, and elemental analysis. Crystallographic characterization is reported for five complexes. Organogold species bearing conjugated aryl substituents on the alkynyl ligand are luminescent. Density‐functional theory calculations on a model complex suggest that emission and the first several absorption transitions result from excited states dominated by the arylacetylide ligand. Excited‐state geometry optimization finds that the lowest‐energy triplet state bears linear, two‐coordinate gold(I) with a miniscule lengthening of the alkynyl carbon–carbon bond. An unusual triplet excited state having a bent geometry at gold lies at higher energy in arylacetylide complexes. For the model terminal acetylideMe3PAuC≡CH, the calculations find this bent state to be the lowest‐energy triplet.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Transmetalation between Au(I) and Sn(IV) complexes. The reaction mechanism in non-coordinating and coordinating polar solvents

“…The slight difference between Au-C1 and Au-C12 bond distances of 2.018(4) and 1.982(4) Å, respectively, can be accounted for the different hybridization of C1(sp 2 ) and C12(sp) atoms. These distances are similar to those observed in other alkynyl-carbene-gold(I) complexes [20][21][22][23][24]. The carbon-carbon bond length of 1.199(6) Å between C12 and C13 corresponds to a typical C"C triple bond in this class of complexes.…”

Synthesis, Characterization and Luminescence of Gold Complexes Bearing an NHC Ligand Based on the Imidazo[1,5‐a]quinolinol Scaffold

“…[7,17,30,31] Despite the high atomic number of gold, the spin-orbit coupling promoted by the gold atom is comparably low and leads to relatively long phosphorescence lifetimes at 77 K, but it is high enough to allow for efficient S 1 -T 1 intersystem crossing. This behaviour can be traced back to the low-lying d orbitals, which are not involved in low-energy electronic transitions.…”

Constrained Digold(I) Diaryls: Syntheses, Crystal Structures, and Photophysics

“…This was scraped with a spatula into the mother liquor, and was collected and dried. Yield: 7 mg (20 %); 1 (77 mg, 0.14 mmol), Cs 2 CO 3 (2 equiv, 90 mg, 0.28 mmol), and phenanthrene-9-boronic acid (2 equiv, 61 mg, 0.27 mmol). Isopropyl alcohol (3 mL) was added, the flask underwent five vacuum/argon cycles.…”

“…This powder was collected, washed with cold methanol, isopropyl alcohol, and pentane, and dried. Yield: 25 mg (75 %); 1 …”

“…For example, alkynylgold(I) complexes are often prepared by the reaction of a gold(I) chloride source with a terminal alkyne and base in protic solvents, in air. [1][2][3][4] Arylgold(I) complexes have historically been synthesized by the reaction of a gold(I)-halide source with an aryllithium generated in situ. [5][6][7] Organogold(I) complexes often carry bulky phosphine ligands [8,9] that suppress aurophilic contacts.…”