Synthesis of the first chiral polynuclear copper(i) complex based on (R)-1-(1-phenyl)ethyl-3-(O,O-diethylthiophosphoryl)thiourea and its characterization in the solid state and solution

The reaction of chiral N-thiophosphorylated thiourea with Cu(ii) acetate is accompanied by copper reduction and leads to the formation of a polynuclear complex with the core composed of six Cu(i) ions alternating with sulfur atoms.

Chirality Control in Crystalline Ni(II) Complexes of Thiophosphorylated Thioureas

Chirality control over the formation of Ni(II) complexes with chiral thiophosphorylated thioureas was achieved via breaking the symmetry of nickel coordination geometry by the introduction of the pyridine ligand, while centrosymmetric meso-complexes are formed from racemic ligands in case of square-planar nickel coordination. Centrosymmetric heterochiral arrangement is observed in crystals of ligands themselves through N–H⋅⋅⋅S hydrogen bonds in intermolecular dimers. Molecular homochirality in tetragonal pyramidal complexes is further transferred to supramolecular homochiral arrangement via key–lock steric interactions.

Mononuclear heteroleptic complexes of copper(i) with 5-phenyl-2,2′-bipyridine and triphenylphosphine: crystal structures, Hirshfeld surface analysis and luminescence properties

The complexes [CuL(PPh₃)Hal] (L = 5-phenyl-2,2′-bipyridine, Hal = Cl⁻, Br⁻) are emissive in the solid state at 298 K, with maxima at 596 and 610 nm, respectively, due to a (M + Hal)LCT excited state.

Luminescent mononuclear mixed ligand complexes of copper(I) with 5-phenyl-2,2'-bipyridine and triphenylphosphine

Reaction of 5-phenyl-2,2'-bipyridine (L) with a mixture of CuI or [Cu(CH3CN)4]BF4 and PPh3 leads to mononuclear heteroleptic complexes [CuL(PPh3)I] (1) and [CuL(PPh3)2]BF4 (2). According to X-ray diffraction, L crystallizes in the monoclinic space group P21/n, exhibiting a disorder over four orientations. Complexes 1 and 2 crystallize in the monoclinic space groups P21/c and P21, respectively. 1 comprises a discrete neutral molecule, while 2 has an ionic structure containing [CuL(PPh3)2](+) and BF4(-). Both structures reveal that each tetracoordinated copper(i) atom is linked to two nitrogen atoms of L, one iodide and one PPh3 in the structure of 1, or two PPh3 in the structure of 2 with the formation of a distorted tetrahedral coordination core. The structure of 2 is additionally stabilized by a weak intramolecular ππ stacking interaction formed between two adjacent phenyl rings of two PPh3 ligands. Hirshfeld surface analysis showed that the structures of both complexes are mainly characterized by HH and CH contacts as well as by IH in the structure of 1 and FH in the structure of 2. The 2D fingerprint plots of two different molecules in the structure of L showed that both molecules exhibit contacts for ππ stacking interactions. The factors important for the stability of 1 and 2 were further quantitatively and qualitatively characterized by the charge and energy decomposition method ETS-NOCV. According to diffuse reflectance spectroscopy in the solid state, free L exhibits bands exclusively in the UV region, while the spectra of 1 and 2 also contain bands in the visible range up to about 500 and 600 nm. All three compounds were found to be emissive in the solid state. DFT calculations have shown that, while emission of L is due to the ligand-centered π→π* transition, luminescence of 1 and 2 was assigned to a (M + X)LCT and MLCT excited states, respectively.