Lewis-Base Adducts of Group 11 Metal(I) Compounds. LI. Synthesis and Structural Characterization of Mononuclear Chloro-, Bromo- and Iodo-pyridinebis(triphenylphosphine)copper(I) Complexes

Abstract

Complexes [ XCu ( py )(PPh3)2], X = Cl, Br, I, py = pyridine, have been synthesized and characterized by single-crystal X-ray structure determination. Chloride and iodide derivatives have similar cells [ isomorphous (?) but not isostructural ], triclinic, pi, a = 19.5 A, b = 10.5, c = 9.6 � , α ≈ 66, β ≈ 86, γ ≈ 83�, Z = 2; the bromide is monoclinic, Cc, a 13.568(9), b 15.760(12), c 16.545(8) � , β 95.65(5)�, Z = 4. Cl, Br, I structures were refined to residuals of 0.042, 0.055, 0.039 for 4288, 2241, 4808 'observed' reflections. In all cases, the copper atom is four-coordinate; for such an array, Cu-X lengths are unusually short [2.318(2), 2.459(2), 2.636(1) � (Cl, Br, I) and Cu-N unusually long (2.14(1) � ], while (Cu-P) increase from 2.264 to 2.288 � across the series. The dominant aspect of the complexes is thus that of XCu (PPh3)2 solvated by pyridine.

Effects of N-heteroaromatic ligands on highly luminescent mononuclear copper(I)–halide complexes

“…Crystal structures of 1-X prepared herein were identical to those reported by Engelhardt et al [21].…”

Synthesis, Characterization, Spectroscopic and Photophysical Properties of New [Cu(NCS){(L‐N)2 or (L′‐NN)}(PPh3)] Complexes (L‐N, L′‐NN = Aromatic Nitrogen Base)

“…[4,5] In ref. [1] the authors commented that "no evidence has been ] dimers. TDDFT/CPCM calculations were used to clarify the type of transitions involved in the UV/Vis absorption spectra, and the corresponding experimental photoemission data were acquired.…”

“…In extending existing studies [1][2][3] to encompass the pseudohalogen X = SCN, it was found that crystallization of [Cu(SCN)(PPh 3 )] from pyridine yielded a complex shown to be a 1:1:2 CuSCN/PPh 3 /py adduct (2), the first of that stoichiometry so defined. It was found to crystallize in a chiral space group and to be strongly luminescent, which prompted study of its photophysical properties, augmented by the synthesis and study of a number of N ∧ Nbidentate ligand counterparts: a new polymorph of [Cu(NCS)(phen)(PPh 3 )] (4) and [Cu(NCS)(bpy)L] (L = PPh 3 , PPh 2 py) (5, 6), all mononuclear.…”

“…Some years ago, from solutions of appropriate stoichiometry of copper(I) halide, CuX (X = Cl, Br, I), triphenylphosphane and pyridine (py) in acetonitrile, adducts of stoichiometry CuX/PPh 3 /py (1:1:1 or 1:2:1) were crystallized and characterized by single-crystal X-ray studies; [1][2][3] similar silver(I) counterparts were also defined. [4,5] In ref.…”

(3-Acetylpyridine-κN)chlorobis(triphenylphosphine-κP)copper(I): a suitable candidate for absolute asymmetric synthesis?

“…As a result, the complex as such is conformationally chiral. A search in the Cambridge Structural Database (CSD; Version 5.27; Allen, 2002) revealed only four similar structures: [CuX(PPh 3 ) 2 (pyridine)], with X = Cl, Br or I (Engelhardt et al, 1989), and [CuI(PPh 3 ) 2 (imidazole)] (CSD refcode: DAFLAY; Wu et al, 2004). These four structures display the same arrangement of ligands around the Cu atom as does (I), except for [CuBr(PPh 3 ) 2 -(pyridine)], where the two triphenylphosphine ligands are mirror images of each other, making the complex achiral.…”