Facile Synthesis of (Phosphine)- and (N-heterocyclic Carbene)Gold(I) and Silver(I) Azide Complexes

Abstract

Two general protocols for the synthesis of N-heterocyclic carbene- or phosphine-ligated gold(I) and silver(I) azide complexes have been developed. The first utilizes thallium(I) acetylacetonate, followed by treatment with trimethylsilyl azide, while the second protocol exploits the relative weakness of d10 metal−oxygen bonds in the reaction of metal(I) acetate with trimethylsilyl azide. Both methods give products in high yield, but only the metal(I) acetate/trimethylsilyl azide method proceeds to completion for an N-heterocyclic carbene-ligated silver(I) acetate. The successful application of this method to silver(I) suggests that this nonaqueous protocol may have general applicability to late transition element or main group acetate precursors. Eight new complexes are reported, of which six are metal azides; four have been crystallographically characterized. Products have been characterized by vibrational and multinuclear NMR spectroscopies and combustion analysis. The synthesis methods described here provide useful alternatives for the syntheses of azide complexes in cases where protic solvents cannot be used.

Isolable, gold carbonyl complexes supported by N-heterocyclic carbenes

“…19 The chemistry of isolable species featuring bonds between gold(I) and unsaturated molecules such as CO, alkenes and alkynes (e.g., [HB (3,5- 6 ], Au(3-hexyne)Cl) [19][20][21][22][23][24] is an area of focus in our laboratory as they are rare, provide valuable fundamental information, and serve as useful models for reaction intermediates. 18,19 The C(2)-Au bond distance in 2 (2.020(4) Å ) is slightly longer than the corresponding bond-distances reported for the N-heterocyclic carbene gold(I) complexes (SIDipp)AuN 3 (1.961(3) Å ) 26 and (SIDipp)AuCl (1.979(3) Å ). The C(2)-Au and Au-CO bond distances are 2.020(4) and 1.971(5) Å , respectively.…”

Recent Advances in Carbon Dioxide Capture, Fixation, and Activation by using N‐Heterocyclic Carbenes

“…The reactivity of 33 toward the CO 2 insertion reaction by nucleophilic attack of the coordinated heteroaryl to CO 2 was negligible. However, this step (CO 2 activation) could proceed through the isomerization of 33 to 41, followed by attack of the free carbene on CO 2 Though numerous Ag-NHC complexes have been synthetized, [169][170][171][172][173][174] reports of reactions of NHC-Ag complexes with CO 2 are limited. [156] This is partly because the AgÀC bond of Ag-NHC complexes is relatively labile.…”

Gold(I) Styrylbenzene, Distyrylbenzene, and Distyrylnaphthalene Complexes: High Emission Quantum Yields at Room Temperature

“…We note www.chemeurj.org that the emission spectra of 5 and 9 show the structured luminescence typical of aryl-ligand-centered emission. [30][31][32]35] Table 5 collects the calculated vertical excitation energies and compositions of singlet excited states up to 300 nm for 2', 5', and 9'. Excitation energies calculated for the first singlet excited states agree well with observed 0-0 energies (within 8 %).…”

“…The corresponding absorption is intense, and the calculations predict it to have the highest oscillator strength of any transition up to 300 nm. We note that the emission spectra of 5 and 9 show the structured luminescence typical of aryl‐ligand‐centered emission 30–32. 35 Table 5 collects the calculated vertical excitation energies and compositions of singlet excited states up to 300 nm for 2′ , 5′ , and 9′ .…”

“…Research in this laboratory has developed the selective auration of carbon skeletons to explore the photophysical consequences of gold attachment. [29][30][31][32][33][34][35] Phosphine-gold(I) fragments are isolobal with a proton. [36] They are soft Lewis acids that activate soft electrophiles, such as p systems.…”