4-Pyridylisocyanide gold(i) and gold(i)-plus-silver(i) luminescent and mechanochromic materials: the silver role

Abstract

X-Ray and DFT studies support that the red-shift of luminescence from [AuAr(CNPy-4)] (Ar = C6F5, C6F3Cl2-3,5) to [Ag[AuAr(CNPy-4)]2](BF4) is not due to non-existent Au⋯Ag interactions but to adoption of structures with shorter Au⋯Au distances.

Optical Properties in Heteronuclear Gold(I)/Silver(I) Complexes of Aliphatic Mixed‐Donor Macrocycles Featuring Metallophilic Interactions

“…In this respect, the luminescence properties of many heteronuclear gold(I) complexes are currently considered of great interest because they are closely related to their structural features, in particular, to the intermolecular interaction patterns in the crystal lattice based on aurophilic, Au(I)•••Au(I), and/or metallophilic Au(I)•••M interactions [M = transition and posttransition closed-shell metal ions such as Ag(I) and Tl(I)]. [4][5][6][7][8][9][10][11] In fact, solid-state phase transitions in these complexes, in response to external stimuli (grinding, but also heating, pressure and interaction with a solvent), which can involve the alteration of the metallophilic interactions and/or molecular arrangements, are generally associated to luminescence emission changes. [4][5][6][7][8][9][10][11][12][13][14][15] Recently, we have considered macrocyclic ligands of different ring size and nature/number of donor atoms to support Au(I)•••M(I) (M = Ag, Tl) metallophillic interactions in the formation of heteronuclear complexes starting from organometallic gold(I) polymeric complexes [{Au(C 6 X 5 ) 2 }M] n (M = Ag(I), Tl(I); X = Cl, F) in low polar solvents (toluene, tetrahydrofuran (THF)).…”

“…[4][5][6][7][8][9][10][11] In fact, solid-state phase transitions in these complexes, in response to external stimuli (grinding, but also heating, pressure and interaction with a solvent), which can involve the alteration of the metallophilic interactions and/or molecular arrangements, are generally associated to luminescence emission changes. [4][5][6][7][8][9][10][11][12][13][14][15] Recently, we have considered macrocyclic ligands of different ring size and nature/number of donor atoms to support Au(I)•••M(I) (M = Ag, Tl) metallophillic interactions in the formation of heteronuclear complexes starting from organometallic gold(I) polymeric complexes [{Au(C 6 X 5 ) 2 }M] n (M = Ag(I), Tl(I); X = Cl, F) in low polar solvents (toluene, tetrahydrofuran (THF)). [16][17][18][19][20][21][22][23][24] The results achieved so far clearly proved a great versatility and potentiality of these ligands, in particular, thioether crowns and mixed thia-aza macrocycles also featuring aromatic moieties, in determining unusual structural archetypes, metal ion dispositions and intermolecular Au(I)•••M(I) interaction patterns in the isolated Au(I)/Ag(I) and Au(I)/Tl(I) heteronuclear complexes.…”

“…Recently, stimuli‐responsive luminescent materials have attracted a great attention because of their potential use in various applications such as photo‐electronic, sensing and recording devices [1,2] . Solid materials that exhibit a switchable luminescence in response to an external mechanical stimulus (shearing, grinding or rubbing) represent a particularly attractive class of photo‐functional materials [3–10] . It is generally recognized that in the absence of a chemical transformation, switching of the luminescence emission behaviour in solid mechanochromic materials is somehow associated to crystalline structural changes in the molecular arrangement motifs and intermolecular interactions in response to the mechanical stimulation.…”

“…In this respect, the luminescence properties of many heteronuclear gold(I) complexes are currently considered of great interest because they are closely related to their structural features, in particular, to the intermolecular interaction patterns in the crystal lattice based on aurophilic, Au(I)⋅⋅⋅Au(I), and/or metallophilic Au(I)⋅⋅⋅M interactions [M=transition and post‐transition closed‐shell metal ions such as Ag(I) and Tl(I)] [4–11] . In fact, solid‐state phase transitions in these complexes, in response to external stimuli (grinding, but also heating, pressure and interaction with a solvent), which can involve the alteration of the metallophilic interactions and/or molecular arrangements, are generally associated to luminescence emission changes [4–15] …”

The 2-isocyanoazulene-gold(I) fragment as a versatile element for organometallic dyes and liquid crystals

“…In this regard, isocyanides are versatile ligands that form stable organometallic complexes with most transition metals [36,37]. Isocyanide metal complexes are of long-standing importance in catalysis [38], diagnostic medicine [39], and material science [40,41], including liquid crystals [42]. Surprisingly, the great potential of isocyanide derivatives has barely been exploited to modulate the properties of azulene systems [43].…”