Gold(i)–carbenes derived from 4-pyridylisocyanide complexes: supramolecular macrocycles supported by hydrogen bonds, and luminescent behavior

Abstract

Monomeric gold(I) carbenes of the type [AuR[C(NR1R2)(NHPy-4)]] (Py-4 = 4-pyridyl) have been prepared with R = C6F5, Fmes (2,4,6-tris(trifluoromethyl)phenyl) by reaction of the corresponding isocyanide compounds [AuR(CNPy-4)] with primary or secondary amines. The single crystal X-ray diffraction structures of [Au(C6F5)[C(NEt2)(NHPy-4)]].OH2, [Au(Fmes)[C(NEt2)(NHPy-4)]], and [Au(Fmes)[C(NHMe)(NHPy-4)]] show that the presence of the NHPy-4 moiety formed induces the formation of supramolecular macrocycles only supported by hydrogen bond interactions, either with N-H groups of other molecules (tetrameric macrocycles), or with water molecules (dimeric macrocycles). Dimeric gold(I) carbenes were also produced using a diamine to form a bridging carbene, or using octafluorobiphenyl to form a Au-C6F4-C6F4-Au bridge, but the solid state structures of these dimers could not be solved. Most of the complexes herein described display luminescent properties.

Metal-Mediated Addition of N-Nucleophiles to Isocyanides: Mechanistic Aspects

“…As a result of the interaction between K 2 [PtCl 4 ] and C≡NMe and the following addition of hydrazine, the first complex of a heteroatom-stabilized carbene was obtained [ 46 , 47 , 48 , 49 ]. Since that time, the metal-mediated addition of the monofunctional O- [ 50 , 51 , 52 , 53 , 54 ], N- [ 34 , 35 , 36 , 37 , 41 , 43 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 ], and other [ 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 ] nucleophiles as well as bifunctional nucleophiles [ 27 , 34 , 53 , 62 , 64 , 79 , 80 , 81 , 82 , …”

“…The N–H nucleophiles with the sp 3 type of the nitrogen orbital hybridization (e.g., amines and hydrazines) are among the most common reagents used in this reaction, and their addition to C≡NR has been intensively exploring over several decades [ 34 , 35 , 36 , 37 , 41 , 43 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 92 ], including the experimental kinetic studies [ 93 , 94 ]. However, surprisingly, despite the long history of these researches, some important aspects of the reaction mechanism still remain unknown, even for the simplest systems.…”

Perylenecarboxydiimide-gold(I) organometallic dyes. Optical properties and Langmuir films

“…[ isomers are possible, depending on the arrangement of the perylene group relative to the gold fragment, only one isomer was observed by 1 H and 19 F NMR spectra at room temperature. Its structure most likely corresponds to the less hindered isomer (depicted in Scheme 2), as found in related systems [46].…”

Carbene Complexes Derived from Metal‐Bound Isocyanides: Recent Advances

“…Monomeric gold(I) carbenes of the type [AuR { C(NR 1 R 2 )(NHPy -4) } ] [Py -4 = 4 -pyridyl; R = C 6 F 5 , F mes = 2,4,6 -tris(trifl uoromethyl)phenyl] have been obtained by reaction of the corresponding isocyanide compounds [AuR(CNPy -4)] with primary (H 2 NMe) or secondary (HNEt 2 ) amines (e.g., Scheme 15.8 ), as reported by Espinet et al [28] .…”

“…In addition, dimeric gold(I) carbenes were obtained using a diamine as a nucleophile (Scheme 15.8 ). Notably, most of the complexes described here display luminescent properties [28] . In a related study conducted by Espinet et al [29] , the isocyanide in complexes [AuX(CNPy -2)] (X = Cl, C 6 F 5 , F mes ) were shown to react with H 2 NMe or HNEt 2 to produce the aminocarbene species [AuX{C(NR 1 R 2 )(NHPy -2)}].…”