Abstract: | Reaction of copper(I) thiocyanate and triphenylphosphane with the bidentate Schiff base N,N′‐bis(trans‐2‐nitrocinnamaldehyde)ethylenediamine {Nca2en, (1); systematic name (1E,1′E,2E,2′E)‐N,N′‐(ethane‐1,2‐diyl)bis3‐(2‐nitrophenyl)prop‐2‐en‐1‐imine]}, C20H18N4O4, in a 1:1:1 molar ratio in acetonitrile resulted in the formation of the complex {(1E,1′E,2E,2′E)‐N,N′‐(ethane‐1,2‐diyl)bis3‐(2‐nitrophenyl)prop‐2‐en‐1‐imine]‐κ2N,N′}(thiocyanato‐κN)(triphenylphosphane‐κP)copper(I)], Cu(NCS)(C20H18N4O4)(C18H15P)] or Cu(NCS)(Nca2en)(PPh3)], (2). The Schiff base and copper(I) complex have been characterized by elemental analyses, IR, electronic and 1H NMR spectroscopy, and X‐ray crystallography from synchrotron data for (1)]. The molecule of (1) lies on a crystallographic inversion centre, with a trans conformation for the ethylenediamine unit, and displays significant twists from coplanarity of its nitro group, aromatic ring, conjugated chain and especially ethylenediamine segments. It acts as a bidentate ligand coordinating via the imine N atoms to the CuI atom in complex (2), in which the ethylenediamine unit necessarily adopts a somewhat flattened gauche conformation, resulting in a rather bowed shape overall for the ligand. The NCS? ligand is coordinated through its N atom. The geometry around the CuI atom is distorted tetrahedral, with a small N—Cu—N bite angle of 81.56 (12)° and an enlarged opposite angle of 117.29 (9)° for SCN—Cu—P. Comparisons are made with the analogous Schiff base having no nitro substituents and with metal complexes of both ligands. |