Beyond Classical Coordination Chemistry: The First Case of a Triply Bridging Phosphine Ligand

Abstract

The first example of a triply bridging (μ3‐P) phosphine ligand has been discovered in the crown‐shaped [Cu3(μ2‐Hal)3L] (Hal=Cl, Br, or I) complexes supported by tris[2‐(2‐pyridyl)ethyl]phosphine (L). Theoretical analysis completely confirms the observed μ3‐P‐bridging pattern, revealing the interaction of the same lone pair of phosphorus with three valence 4s‐orbitals of Cu atoms. The presented complexes exhibit outstanding blue phosphorescence (λem=442–465 nm) with the quantum efficiency reaching 100 %. The complex [Cu3(μ2‐I)3L] also exhibits remarkable thermo‐ and mechanochromic luminescence resulting in a sharp change in the emission colour upon external stimuli. These findings essentially contribute to coordination chemistry of the pnictine ligands.

Coinage Metal Complexes of Bis(quinoline‐2‐ylmethyl)phenylphosphine‐Simple Reactions Can Lead to Unprecedented Results

“…These short metal‐metal contacts can strongly influence the properties of the resulting complexes [20–25] . Nevertheless, conformation and composition of the complexes of coinage metals with P,N ligands are rather unpredictable due to the reactivity and diverse coordination capabilities of such ligands [26–28] . The newly synthesized Cu I , Ag I and Au I complexes of bis(quinolin‐2‐ylmethyl)phenylphosphine ( bqmpp ), presented in the following, complement the great variety of complexes of coinage metals and impressively demonstrate the unique coordination behavior of P,N ligands.…”

“…[20][21][22][23][24][25] Nevertheless, conformation and composition of the complexes of coinage metals with P,N ligands are rather unpredictable due to the reactivity and diverse coordination capabilities of such ligands. [26][27][28] The newly synthesized Cu I , Ag I and Au I complexes of bis(quinolin-2-ylmethyl)phenylphosphine (bqmpp), presented in the following, complement the great variety of complexes of coinage metals and impressively demonstrate the unique coordination behavior of P,N ligands. The new complexes have been characterized by multinuclear ( 1 H, 13 C, 31 P, 11 B, 19 F) 1D and 2D NMR spectroscopy as well as by single-crystal X-ray diffraction analysis, elemental analysis and mass spectrometry.…”

Structural characterization and luminescence properties of trigonal Cu(i) iodine/bromine complexes comprising cation–π interactions

“…350 nm. With reference to previous spectral studies of the Cu(I) halide complex systems, 46,47 these distinct low-lying absorption bands are tentatively attributed to an admixture of the metal-to-ligand charge transfer (MLCT) transition and halide-to-ligand charge transfer transition (XLCT).…”

Impact of Intermolecular Non‐Covalent Interactions in a CuI8PdII1 Discrete Assembly: Conformers’ Geometries and Stimuli‐Sensitive Luminescence Properties

“…[13] Artem'ev et al also recently described the first Cu I trimers reported to date to be stabilized by triply bridging phosphine ligand in which the mechanochromic behaviors observed are assigned by the authors to the crystalline to amorphous phase transition and concomitant local molecular geometry reorganizations. [14] Herein, we report firstly the polymorphic behavior of a luminescent [Cu 8 Pd 1 (CN) scaffold is characterized by a lower symmetry in which the intermetallic Cu I distances are different resulting from alternative set of coordination modes of the internal cyanide ligands. The electronic structures and thus the photophysical properties are concomitantly impacted by the conformation adopted.…”

“…[13] Artem'ev et al also recently described the first Cu I trimers reported to date to be stabilized by triply bridging phosphine ligand in which the mechanochromic behaviors observed are assigned by the authors to the crystalline to amorphous phase transition and concomitant local molecular geometry reorganizations. [14] Herein, we report firstly the polymorphic behavior of a luminescent [Cu 8 Pd 1 (CN) 8 dppm 8 ](PF 6 ) 2 , thereafter named Cu I 8 Pd II 1 , discrete polymetallic assembly (dppm = 1,1bis(diphenylphosphino)methane). While the 'open-form' B o was initially reported as being the only phase obtained upon crystallization, we have observed recently the formation upon the same crystallization conditions of traces of a 'closed-form', B c (Scheme 1).…”