Dinuclear Diphosphine Complexes of Gold(I) Alkynyls, the Effects of Alkynyl Substituents onto Photophysical Behavior

Abstract

A series of dinuclear diphosphine complexes of gold(I) alkynyls containing bis(diphenylphosphanyl)ethane/propane and alkynyl ligands with aromatic substituents (biphenyl, pyrene, and azobenzene) was synthesized and characterized using X‐ray crystallography and NMR spectroscopy. Photophysical parameters of the compounds obtained strongly depend on the nature of aromatic substituents in the alkynyl ligands. Azobenzene containing derivatives are non‐luminescent, whereas biphenyl and pyrene containing complexes display moderate emission both in solution and in solid state. The complexes with biphenyl substituents display strong heavy atom effect and show typical phosphorescent emission. In contrast, the complexes containing pyrene chromophore are fluorescent that points to the absence of spin orbit coupling in these systems, which additionally display static excimer emission in solid phase due to ground state π‐stacking of the pyrene moieties.

Effect of Gold(I) on the Room‐Temperature Phosphorescence of Ethynylphenanthrene

“…The Au−C and C≡C distances and P‐Au‐C and Au‐C≡C angles (Table 1) are in the usual ranges for Au I alkynyl complexes [28, 31–41] . Linear coordination of the phenanthrene ligands at the Au I centers is observed, with P‐Au‐C angles of 172.6–179.0°.…”

Luminescent phosphine gold(I) alkynyl complexes. Highlights from 2010 to 2018

“…[49] The nature of the chromophore on the population of triplet state was analyzed in compounds 53, 55 and 56 where 3 IL, 1 IL transitions and no significant luminescence (due to well-known quenching effect of the azobenzene group) was recorded respectively both with dppe and dppp diphosphines. [50] Compounds 54 behave as 55 with 1 IL transitions in all cases and thus, it seems that SOC is more favored for polybenzene than for those complexes containing fused carbon-aromatic groups as well-known organic luminophores such as pyrene and anthracene.…”

“…H 2 N dppa (50a), dppet (50b), dppe (50c), dppp (50d) [16] N dppe (51) [15] N dppm (52a), dppb (52b); dcypm (52c), dcypb (52d) [49] dppe (53a), dppp (53b) [50] dppb (54a), dpppent (54b), dpph (54c) [58] dppe (55a), dppp (55b) [50] N N dppe (56a), dppp (56b) [50] Ph dppz (57a), dpbp (57b), dpib (57c)…”

Alkynylgold(I) C3‐Chiral Concave Complexes: Aggregation and Luminescence

“…Gold(I) alkynyl complexes with phosphine or isonitrile ancillary ligands, since the first report in 1959, [1] received increasing attention after their unique photophysical properties, [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] coupled to the possibility of intramolecular aurophilic interactions in polynuclear complexes, [21][22][23][24][25][26][27] and intermolecular Au•••Au short contacts in the solid state [5,[28][29][30] or in supramolecular assemblies [31][32][33] had been recognized. [34,35] The interest in these compounds was currently raised by the applications [36] of their luminescence properties to the development of materials for (opto)electronics, [37,38] sensing, [23,26,27,39,40] and cellular imaging.…”