A five-coordinate copper(II) perchlorate complex with tris(N-methylbenzimidazol-2-ylmethyl)amine and salicylate

A five-coordinate copper(II) complex with the tripod ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and salicylate, with the composition [Cu(Mentb) (salicylate)](ClO₄) · 2DMF, was synthesized and characterized by elemental and thermal analyses, electrical conductivity, IR and UV-Vis spectral measurements. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. The Cu(II) is five-coordinate with four N atoms from the Mentb ligand and an O atom of the monodentate salicylate ligand. The N₄O donors are in a distorted trigonal-bipyramid geometry. Cyclic voltammograms indicate a quasireversible Cu²⁺/Cu⁺ couple. The X-band EPR spectrum of the complex confirms the trigonal-bipyramidal structure with g_∥ < g _⊥ and a very small value of A_∥ (41 × 10^?4 cm^?1).     

Synthesis,crystal structure,and properties of a seven-coordinate manganese(II) complex formed with the tripodal tetradentate ligand tris (N -methylbenzimidazol-2-ylmethyl)amine and salicylate

A seven-coordinate manganese(II) complex with the tripod tetradentate ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb), [Mn(Mentb)(salicylate)(DMF)](ClO₄) ? (DMF), was synthesized and characterized by elemental, electrical conductivity, infrared, and UV-Vis spectral measurements. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. Mn^II is bonded to a Mentb, a salicylate and dimethylformamide through four nitrogens and three oxygens, resulting in seven-coordination. Cyclic voltammograms of the complex indicate a quasi-reversible Mn³⁺/Mn²⁺ couple. The X-band electron paramagnetic resonance spectrum exhibits a six-line manganese hyperfine pattern with g = 2, A = 93, confirming that the material is high-spin Mn(II).     

Synthesis,crystal structure and properties of a novel copper(II) complex with tripod ligand tris(1H-benzimidazol- 2-ylmethyl)amine

A five-coordinate copper complex with the tripod ligand tris(1H-benzimidazol-2-ylmethyl)amine (ntb), of composition [Cu(ntb)(H₂O)] (C1O₄)₂?·?C₅H₄N₂O₃?·?H₂O (C₅H₄N₂O₃?=?4-nitropyridine-N-oxide), was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and U.V. The crystal structure of the copper complex has been determined by single-crystal X-ray diffraction, and shows that the Cu^II is bonded to a tris(1H-benzimidazol-2-ylmethyl)amine (ntb) ligand and a water molecule through four N atoms and one O atom, giving a distorted trigonal–bipyramidal coordination geometry with approximate C ₃ molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasi-reversible Cu⁺²/Cu⁺ couple. Electron spin resonance data confirm a trigonal-bipyramidal structure and with g ₂?<?g _ζ and a very small value of A ₂ (20?×?10^?4?cm^?1).     

Synthesis and crystal structure of a copper(II) complex of the tripodal tetradentate ligand tris(2-benzimidazolylmethyl)amine

A mononuclear copper complex [Cu(NTB)Cl]Cl·3CH₃CH₂OH (1) (NTB?=?tris(2-benzimidazolylmethyl)amine) was synthesized and its structure was determined by single crystal X-ray diffraction. In this complex, copper(II) is five-coordinate with NTB serving as a neutral tetradentate ligand. Three tertiary nitrogen atoms of benzimidazole groups of NTB formed the base of the trigonal bipyramidal geometry. One axial position was occupied by the apical nitrogen atom of NTB and the other was occupied by chloride. The ESR spectrum of complex 1 in ethanol at 101?K was recorded and the well-defined ESR parameters (g _∥?=?2.02, g _⊥ =?2.16 and A _∥ ^?=?109?G) indicated that the Cu(II) has a distorted trigonal-bipyramidal environment, in good agreement with crystal structure determination for complex 1.     

Synthesis,structure, and DNA-binding properties of manganese(II) and zinc(II) complexes with tris(<Emphasis Type="Italic">N</Emphasis>-methylbenzimidazol-2-ylmethyl)amine ligand

Tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and its two complexes, [Mn(Mentb)(DMF)(H₂O)](pic)₂ 1 and [Zn(Mentb)(pic)](pic) 2 (pic = picrate), have been synthesized and characterized by physico-chemical and spectroscopic methods. Single crystal X-ray diffraction revealed that the two complexes have different structures. In complex 1, the coordination sphere around Mn(II) is distorted octahedral, whereas in complex 2 the coordination sphere around Zn(II) is distorted trigonal bipyramidal. The DNA-binding properties of the free ligand and its two complexes have been investigated by electronic absorption, fluorescence, and viscosity measurements. The results suggest that the ligand and its two complexes bind to DNA via an intercalation binding mode, and their binding affinity for DNA follows the order 1 > 2 > ligand.     

A zinc(II) complex with tris(2-( N -methyl)benzimidazlylmethyl)amine and salicylate: synthesis,crystal structure,and DNA-binding

A five-coordinate zinc complex with tris(2-(N-methyl)benzimidazylmethyl)amine (Mentb) and salicylate, with composition [Zn(Mentb)(salicylate)](NO₃), was synthesized and characterized by elemental analysis, IR and UV-Vis spectral measurements. The crystal structure of the zinc complex shows that Zn(II) is bonded to tris(2-(N-methyl)benzimidazylmethyl)amine (Mentb) and a salicylate through four nitrogens and one oxygen, and the coordination geometry is best described as distorted trigonal-bipyramid. The DNA-binding of the Zn(II) complex and Mentb were investigated by spectrophotometric methods and viscosity measurements, and the results suggest that the Zn(II) complex binds to DNA via intercalation; the binding affinity of the Zn(II) complex to DNA is greater than Mentb. Additionally, Zn(II) complex exhibited potential to scavenge hydroxyl radical in vitro.     

Structural studies of (prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine hetero‐scorpionate copper complexes

The structures of five compounds consisting of (prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine complexed with copper in both the Cu^I and Cu^II oxidation states are presented, namely chlorido{(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ³N,N′,N′′}copper(I) 0.18‐hydrate, [CuCl(C₁₅H₁₇N₃)]·0.18H₂O, (1), catena‐poly[[copper(I)‐μ₂‐(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ⁵N,N′,N′′:C²,C³] perchlorate acetonitrile monosolvate], {[Cu(C₁₅H₁₇N₃)]ClO₄·CH₃CN}_n, (2), dichlorido{(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ³N,N′,N′′}copper(II) dichloromethane monosolvate, [CuCl₂(C₁₅H₁₇N₃)]·CH₂Cl₂, (3), chlorido{(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ³N,N′,N′′}copper(II) perchlorate, [CuCl(C₁₅H₁₇N₃)]ClO₄, (4), and di‐μ‐chlorido‐bis({(prop‐2‐en‐1‐yl)bis[(pyridin‐2‐yl)methylidene]amine‐κ³N,N′,N′′}copper(II)) bis(tetraphenylborate), [Cu₂Cl₂(C₁₅H₁₇N₃)₂][(C₆H₅)₄B]₂, (5). Systematic variation of the anion from a coordinating chloride to a noncoordinating perchlorate for two Cu^I complexes results in either a discrete molecular species, as in (1), or a one‐dimensional chain structure, as in (2). In complex (1), there are two crystallographically independent molecules in the asymmetric unit. Complex (2) consists of the Cu^I atom coordinated by the amine and pyridyl N atoms of one ligand and by the vinyl moiety of another unit related by the crystallographic screw axis, yielding a one‐dimensional chain parallel to the crystallographic b axis. Three complexes with Cu^II show that varying the anion composition from two chlorides, to a chloride and a perchlorate to a chloride and a tetraphenylborate results in discrete molecular species, as in (3) and (4), or a bridged bis‐μ‐chlorido complex, as in (5). Complex (3) shows two strongly bound Cl atoms, while complex (4) has one strongly bound Cl atom and a weaker coordination by one perchlorate O atom. The large noncoordinating tetraphenylborate anion in complex (5) results in the core‐bridged Cu₂Cl₂ moiety.     

Synthesis,Crystal Structure,and Characterization of Two Novel Five‐coordinate Zinc(II) Complexes with the Tripod Ligand Tris(N‐methylbenzimidazol‐2‐yl‐methyl)amine and α,β‐unsaturated Carboxylates

Two novel five‐coordinate zinc(II) complexes with the tripod ligand tris(N‐methylbenzimidazol‐2‐ylmethyl)amine (Mentb) and two different α,β‐unsaturated carboxylates, with the composition [Zn(Mentb)(acrylate)] (ClO₄)·DMF·1.5CH₃OH ( 1 ) and [Zn(Mentb)(cinnamate)](ClO₄)·2DMF·0.5CH₃OH ( 2 ), were synthesized and characterized by means of elemental analyses, electrical conductivity measurements, IR, UV, and ¹H NMR spectra. The crystal structure of two complexes have been determined by a single‐crystal X‐ray diffraction method, and show that the Zn^II atom is bonded to a Mentb ligand and a α,β‐unsaturated carboxylate molecule through four N atoms and one O atom, resulting in a distorted trigonal‐bipyramidal coordination [τ( 1 ) = 0.853, τ( 2 ) = 0.855], with approximate C₃ symmetry.     

Copper(II) Complexes with Chiral Diaminodiamido Ligands: Solution and Structural Studies

Abstract

Three diaminodiamido ligands (S,S)-N,N′-bis(prolyl)ethanediamine (ProNN-2), (S,S)-N,N′-bis(N-methylvalyl)ethanediamine (Me₂ValNN-2), and (S,S)-N,N′-bis(N-methylphenylalanyl)-ethanediamine (Me₂PheNN-2) were synthesised and their complex formation equilibria with copper(II) investigated in aqueous solution by potentiometry and, for ProNN-2, by electronic spectrophotometry. ProNN-2 forms the species [CuLH]³⁺, [Cu₂L₂]⁴⁺, [Cu₂L₂H_?2]²⁺ and [CuLH_?2], Me₂PheNN-2 forms the complexes [CuLH]³⁺, [Cu₂L₂H_?2]²⁺ and [CuLH_?2], whereas Me₂ValNN-2 forms the monomer [CuLH_?1]⁺ but not the dimer. The dimeric cation [Cu₂L₂H_?2]²⁺, of Me₂PheNN-2 has severe steric requirements, as demonstrated by the X-ray crystal structure of the complex [Cu₂L₂H_?2]Cl₂· 12H₂O, of the corresponding non-methylated ligand. Since copper(II) complexes of the ligands examined are used as additives to the mobile phase to perform chiral resolution of D,L-amino acids in RP-HPLC, the present results provide valuable clues to an understanding of the mechanism of the enantiomeric separation.     

Copper(II) complexes of tridentate selenobisphenolate ligand in mixed ligand environments: Synthesis, crystal structure, EPR and electrochemical studies

A series of square-pyramidal copper(II) complexes, [Cu(L^Se)(N^∧N)] (H₂L^Se = seleno-bisphenolate; N^∧N = bipyridyl, phenanthroline or N,N-dimethylethylenediamine) have been synthesized and characterized by elemental analyses, magnetic measurements, IR, EPR, and electronic spectral studies. Single crystal X-ray structures of [Cu(L^Se)(bpy)]·H₂O (2), [Cu(L^Se)(phen)]·CH₂Cl₂ (3) and [Cu(L^Se)(N,N-Me₂en)] (4) showed that all the complexes have approximately square-pyramidal geometry. In complexes 2 and 3, the square plane is occupied by O(1), O(2), N(1) and N(2) and the apical position by Se atom of L^{Se 2−} ligand. The asymmetric unit of complex 4 contains two crystallographically independent discrete molecules A and B with CuN₂OSe chromophore comprising the square plane and the axial position being occupied by another phenolate oxygen atom. Complexes 2, 3 and 4 are found to be paramagnetic and EPR parameters extracted are: g_∥ = 2.232, g_⊥ = 2.069; 〈g_eff〉 = 1.95; and g_∥ = 2.232, g_⊥ = 2.083 for complexes 2, 3 and 4, respectively. Both the complexes 2 and 4 show three reduction processes: (a) a quasi-reversible reduction of Cu^II to Cu^I, (b) an irreversible reduction of Cu^I to Cu⁰ with the release of free ligand, and (c) a reduction process occurs at this coordinated ligand. They also show a well-defined quasi-reversible oxidation of Cu^II to Cu^III and an irreversible oxidation peak at ∼1.30 and 1.40 V vs. Ag/AgCl for 4 and 2, respectively, with no cathodic counterpart, and were attributed to the oxidation of the metal coordinated ligand.     

A V-shaped ligand bis(N-methylbenzimidazol-2-ylmethyl) benzylamine with its cobalt(II) complex: synthesis,crystal structure,DNA-binding properties,and antioxidant activity

A V-shaped ligand bis(N-methylbenzimidazol-2-ylmethyl)benzylamine (bmbb) and its cobalt complex, [Co(bmbb)₂](pic)₂ (pic?=?picrate), have been synthesized and characterized by physico-chemical and spectroscopic methods. Single-crystal X-ray revealed that the coordination sphere around Co(II) is distorted octahedral with an N₆ ligand set from two tridentate bmbb. The DNA-binding properties of bmbb and the Co(II) complex were investigated by spectrophotometric and viscosity measurements. The results suggest that bmbb and Co(II) complex both bind to DNA via intercalation, and the Co(II) complex binds to DNA more strongly than bmbb. The Co(II) complex also exhibited potential antioxidant properties in vitro studies.     

Ion exchange properties of β-eucryptite (LiAlSiO4): EPR investigation on copper-doped single crystals

Investigation of the ion exchange properties of β-eucryptite (LiAlSiO₄) single crystals indicates that it is impossible to substitute Li⁺ by other bigger univalent cations such as Na⁺, K⁺, or Ag⁺. On the contrary, Li⁺ exchange by bivalent cations, Cu²⁺ or Mn²⁺, is very easy. For a general orientation of the crystal with respect to the magnetic field, the EPR spectrum of Cu²⁺ ions in β-eucryptite consists of 12 sharp lines partially superimposed on a broad line. The sharp lines are attributed to isolated copper ions in the conducting channels. Cu²⁺ lies in sixfold coordinated Li″ sites, but not in the fourfold coordinated Li″ sites. The corresponding spin Hamiltonian parameters at T = 140 K are found to be: g_x = 2.362, g_y = 2.340, g_z = 1.990; ∥A_x∥ = 85 × 10^?4cm^?1, ∥A_y∥ = 71 × 10^?4cm^?1, ∥A_z∥ = 203 × 10^?4 cm^?1. The broad line is attributed to clusters of Cu²⁺ located in neighboring Li″ sites.     

A coordination polymer consisting of two different one‐dimensional copper(II) chains

The title compound, catena‐poly[[[diaqua(methanol‐κO)copper(II)]‐μ‐N‐(4‐methylpyrimidin‐2‐yl‐κN¹)pyrazin‐2‐amine‐κ²N¹:N⁴] [[aqua(aqua/methanol‐κO)(perchlorato‐κO)copper(II)]‐μ‐N‐(4‐methylpyrimidin‐2‐yl‐κN¹)pyrazin‐2‐amine‐κ²N¹:N⁴] tris(perchlorate) methanol monosolvate 1.419‐hydrate], {[Cu(C₉H₉N₅)(CH₃OH)(H₂O)₂][Cu(C₉H₉N₅)(ClO₄)(CH₃OH)_0.581(H₂O)_1.419](ClO₄)₃·CH₃OH·1.419H₂O}_n, is a one‐dimensional straight‐chain polymer of N‐(4‐methylpyrimidin‐2‐yl)pyrazin‐2‐amine (L) with Cu(ClO₄)₂. The complex consists of two crystallographically independent one‐dimensional chains in which the Cu^II atoms exhibit two different octahedral coordination geometries. The L ligand coordinates to two Cu^II centres in a tridentate manner, with the pyrazine ring acting as a bridge linking the Cu^II coordination units and building an infinite one‐dimensional chain. Extensive hydrogen bonding among perchlorate anions, water molecules and L ligands results in three‐dimensional networks.     

Synthesis,crystal structure,DNA-binding properties,and antioxidant activity of a V-shaped ligand bis(N-methylbenzimidazol-2-ylmethyl)benzylamine and its zinc(II) complex

A V-shaped ligand bis(N-methylbenzimidazol-2-ylmethyl)benzylamine (L) and its zinc(II) complex, [ZnL ₂](pic)₂?·?2CH₃CN (pic?=?picrate), have been synthesized and characterized by physico-chemical and spectroscopic methods. Single-crystal X-ray crystallographic analysis revealed that the Zn(II) complex possesses a distorted trigonal bipyramidal geometry. Supramolecular interactions arising from various intra- or intermolecular π···π stacking interactions contributed to the form of the multidimensional configuration. Interactions of L and Zn(II) complex with DNA were monitored using spectrophotometric methods and viscosity measurements. The results suggest that L and Zn(II) complex both bind to DNA via intercalation and Zn(II) complex binds to DNA more strongly than L. Moreover, the Zn(II) complex also exhibited potential antioxidant properties in vitro.     

Electrochemical Examination of Copper(II) Complexes with Octaazamacrocyclic Ligand and Heterocyclic Dithiocarbamate

Mixed ligand dinuclear copper(II) complexes of the general formula [Cu₂(Rdtc)tpmc)](ClO₄)₃ with octaazamacrocyclic ligand tpmc and four different heterocyclic dithiocarbamate ligands Rdtc^?, as well as the complexes [Cu₂(tpmc)](ClO₄)₄ and [Cu(tpmc)](ClO₄)₂?2H₂O were studied in aqueous NaClO₄ and HClO₄ solutions by cyclic voltammetry on glassy carbon electrode. The electrochemical properties of the ligands and Cu(II) complexes were correlated with their electronic structure. Conductometric experiments showed different stoichiometry in complexation of tpmc with Cu²⁺ ions and transport of ions in acetonitrile and in aqueous media. These studies clarified the application of this macrocyclic ligand as ionophore in a PVC membrane copper(II) selective electrode and contributed elucidation of its sensor properties.     

Chloro­(hist­amine)(1,10‐phenanthro­line)copper(II) chloride monohydrate

In the cationic complex present in the title compound, chloro­[2‐(4‐imidazolyl‐κN¹)­ethyl­amine‐κN](1,10‐phenanthroline‐κ²N,N′)copper(II) chloride monohydrate, [CuCl(C₅H₉­N₃)­(C₁₂H₈N₂)]Cl·H₂O, the metal centre adopts a five‐coordinate geometry, ligated by the two phenanthroline N atoms, two amine N atoms of the hist­amine ligand (one aliphatic and one from the imidazole ring) and a chloro ligand. The geometry around the Cu atom is a distorted compressed trigonal bipyramid, with one phenanthroline N and one imidazole N atom in the axial positions, and the other phenanthroline N atom, the histamine amine N atom and the chloro ligand in the equatorial positions. The structure includes an uncoordinated water mol­ecule, and a Cl⁻ ion to complete the charge. The water mol­ecule is hydrogen bonded to both Cl⁻ ions (coordinated and uncoordinated), and exhibits a close Cu⋯H contact in the equatorial plane of the bipyramid.     

Copper(II) complexes containing hemilabile tridentate ligand as chromotropic probes

Two copper(II) complexes with the general formula [Cu(L)(H₂O)](ClO₄)₂ (1) and [Cu(L)₂](ClO₄)₂ (2), where L=3-((pyridin-2-ylmethyl)amino)propanamide, were synthesized and characterized by elemental analyses, IR, UV–vis spectroscopy techniques and molar conductance measurements. The crystal structures of the complexes were identified by single crystal X-ray diffraction analysis. The tridentate ligand L acts as an N₂O-donor through the nitrogen atoms of the pyridine and amine moieties as well the oxygen atom of the amide group. The copper(II) ions in both complexes have distorted octahedron structures so that the Cu(II) ion in 1 is coordinated by an aqua ligand and a tridentate ligand defining the basal plane, and by two oxygen atoms of the perchlorate ions occupying the axial positions. However, two ligands L are coordinated to the copper(II) ion in 2, where four nitrogen atoms of pyridine and amine groups occupy the equatorial positions and two oxygen atoms of the amide moieties exist in the apices. The chromotropism (halo-, solvato- and ionochromism) of both complexes were studied using visible absorption spectroscopy. The complexes are soluble in water and organic solvents and display reversible halochromism. The solvatochromism property is due to structural change followed by solvation of the vacant sites of the complexes. The complexes demonstrated obvious ionochromism and are highly sensitive and selective towards CN^? and N₃^? anions in the presence of other halide and pseudo-halide ions.     

(2‐Aminopyrimidine‐κN1)aqua(pyridine‐2,6‐dicarboxylato‐κ3O2,N,O6)copper(II): X‐ray and DFT calculated structure

In the title compound, [Cu(C₇H₃N₂O₄)(C₄H₅N₂)(H₂O)], (I), pyridine‐2,6‐dicarboxylate (pydc²⁻), 2‐aminopyrimidine and aqua ligands coordinate the Cu^II centre through two N atoms, two carboxylate O atoms and one water O atom, respectively, to give a nominally distorted square‐pyramidal coordination geometry, a common arrangement for copper complexes containing the pydc²⁻ ligand. Because of the presence of Cu...X_bridged contacts (X = N or O) between adjacent molecules in the crystal structures of (I) and three analogous previously reported compounds, and the corresponding uncertainty about the effective coordination number of the Cu^II centre, density functional theory (DFT) calculations were used to elucidate the degree of covalency in these contacts. The calculated Wiberg and Mayer bond‐order indices reveal that the Cu...O contact can be considered as a coordination bond, whereas the amine group forming a Cu...N contact is not an effective participant in the coordination environment.     

Synthesis,characterization, and superoxide dismutase activity of two new copper(II) complexes of benzoylpyridine 4-phenylsemicarbazone

Two mononuclear complexes containing copper(II) and 2-benzoylpyridine 4-phenylsemicarbazone (BPS) and pseudohalides, [Cu(BPS)(N₃)] (1) and [Cu(BPS)(NCS)(H₂O)]NO₃ (2) have been synthesized and characterized by UV-Vis, Fast atom bombardment, electron paramagnetic resonance, and infrared spectroscopy. Crystal structures of these two complexes have been resolved by using single crystal X-ray studies. Complex 1 crystallizes in the triclinic lattice with space group P1 and is a distorted square planar geometry. Complex 2 also crystallizes in the triclinic lattice with space group P1 but is a distorted square pyramidal geometry with N₃O₂ chromophore. Both the complexes have g _∥ > g _┴ > 2.0023 and a G value less than 4, consistent with a d _{x ²? y ²} ground state. Superoxide dismutase activities have also been examined.     

Synthesis,characterization and crystal structures of the bidentate Schiff base N,N′‐bis(2‐nitrocinnamaldehyde)ethylenediamine and its complex with CuNCS and triphenylphosphane

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)bis[3‐(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)bis[3‐(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 Cu^I 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 Cu^I 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.