Gold(I) Complexes Containing Phosphanyl‐ and Arsanylborane Ligands

Abstract

The structural and photophysical properties of a series of new Au I compounds have been studied. The reactionso fA uCl(tht) with the phosphanyl-and arsanylboranes RR ' EBH 2 NMe 3 (E = P, As;R = H, Ph;R ' = H, Ph, tBu) afford the complexes [AuCl(RR ' EBH 2 NMe 3 )].I nt he solid state, [AuCl(H 2 PBH 2 NMe 3 )] 2 (2a)i sad imer showingu nsupported intermolecular aurophilic interactionsw ith short Au···Au distances. In contrast,[ AuCl(H 2 AsBH 2 NMe 3 )] n (2b) aggregates to form 1D chains. Organic substituentso n the pnictogen atomsl ead to discrete moleculesi n [AuCl(RR ' PBH 2 NMe 3 )] (2c:R = H, R' = tBu; 2d:R = R' = Ph). To increase the aurophilicity,t he ionic homoleptic complexes [Au(RR ' EBH 2 NMe 3 ) 2 ][AlCl 4 ]( 3a-d)h ave been synthesized, for which 3a,b form chains in the solid state and exhibit luminescence. The emissions show ad rastic redshift with temperature decrease, correlating with decreasing Au···Au distances.D FT calculations provide insight into the bondings ituation of the products. [a] J. Braese, Dr.M.B odensteiner,Prof. Dr.M .

Excimer and Exciplex Formation in Gold(I) Complexes Preconditioned by Aurophilic Interactions

“…Thee mission spectra of the homoleptic, aurophilically associated cationic complexes [(Me 3 NBH 2 MH 2 ) 2 Au]AuCl 4 (M = P, As) have been studied in the solid state. [146] The complexes form chains in the crystals,and the two emissions per complex in the blue to violet region have been found (by DFT calculations) to be MC,a nd to occur between conduction and valence band configurations.T he energy of the T 1 !S 0 intersystem crossing (final relaxation) may be manipulated:Decreasing the temperature manifests itself in ashortening of the ground state Au-Aus eparation;t he orbital overlap in the excited state is enhanced, the band gap decreases,a nd ar ed-shift ensues.T he effect of temperature on the Au-Audistances in linear chains of gold complexes in solids to acertain extent mirrors that of increasing hydrostatic pressure as discussed above (Section 4.3.1).…”

Excimer‐ und Exciplex‐Bildung in durch aurophile Wechselwirkungen präkonditionierten Gold(I)‐ Komplexen

“…Die Emissions‐Spektren der homoleptischen, über aurophile Wechselwirkungen assoziierten kationischen Komplexe [(Me 3 NBH 2 MH 2 ) 2 Au]AuCl 4 (M=P, As) wurden im Festkörper untersucht . In den Kristallen bilden die Komplexe Ketten, und die beiden Emissionen jedes einzelnen Komplexes im blauen bis violetten Bereich sind (laut DFT‐Rechnungen) MC und finden zwischen Leitungs‐ und Valenzband‐Konfigurationen statt.…”

Bidentate Phosphanyl‐ and Arsanylboranes

“…Further, it was shown, that the exchange of a CC unit against an isoelectronic and isosteric BN moiety will not lead to a remarkable change in the molecular steric effects, but will affect the electronic structure of the molecule through the introduction of a dipole . As a result, bidentate amines should be suitable LBs to connect phosphanylboranes, leading to potential new ligands ( V ) with different features for example, in catalysis or by forming higher aggregates, compared to bidentate organophosphines. Considering the huge variety of bidentate organophosphine compounds, it is rather surprising that there are no neutral bidentate phosphanylboranes ( V ) known yet.…”

“…In contrast to 4 b , which is well soluble in all polar solvents, the parent compound 4 a reveals poor solubility after crystallization. In comparison to 2 a / b , the resonance signals in the NMR spectra of 4 a and 4 b are shifted downfield, due to the coordination to Au I . Whereas the hydrogen‐substituted parent phosphanylborane forms a polymeric structure with aurophilic interactions of the Au atoms in 4 a , the steric bulk of the phenylsubstituents in 4 b prevents such interactions and a dinuclear structure is formed (Figure ).…”

“…In comparison to 2a/b,t he reso-nance signals in the NMR spectra of 4a and 4b are shifted downfield, due to the coordination to Au I . [16] Whereas the hydrogen-substituted parent phosphanylboranef orms ap olymeric structure with aurophilic interactions of the Au atoms in 4a,t he stericb ulk of the phenylsubstituents in 4b prevents such interactions and ad inuclear structure is formed (Figure 3). The gold atoms in 4a show shorter intra-(3.231(1) ), as well as longer intermolecular (3.359(1) )i nteractions.…”