Syntheses,Structural, and Spectroscopic Properties of Copper(II) Complexes of Constrained Macrocyclic Ligands

The complexes [Cu(L¹)(H₂O)₂](BF₄)₂ · 2H₂O ( 1 ) [L¹ = 5, 16‐dimethyl‐2, 6, 13, 17‐tetraazatricyclo(14, 4, 0^1.18,0^7.12)docosane] and 0.5[Cu(L²)(NO₃)₂][Cu(L²)](NO₃)₂ ( 2 ) [L² = dibenzyl‐5, 16‐dimethyl‐2, 6, 13, 17‐tetraazatricyclo(14, 4, 0^1.18,0^7.12)docosane] were synthesized and characterized by single crystal X‐ray analyses. In these constrained macrocycles, the central copper(II) atoms are in a tetragonally distorted octahedral environment with four nitrogen atoms of the macrocyclic ligands in equatorial positions and oxygen atoms from either water molecules or nitrato groups in axial positions. The macrocyclic ligands in both complexes adopt the most stable trans‐III conformation. The Cu–N distances [1.999(7)–2.095(7) Å] are typical for such complexes, but the axial ligands are weakly coordinating Cu–OH₂ bonds [2.693(3) Å] and Cu–ONO₂ bonds [2.873(7) Å] due to the combination of the pseudo Jahn–Teller effect and strong in‐plane ligand field. The crystals are stabilized by a three‐dimensional network by hydrogen bonds that are formed among the secondary nitrogen hydrogen atoms, oxygen atoms of water molecules, fluorine atoms of BF₄^–, and oxygen atoms of NO₃^–. The electronic absorption and IR spectroscopic properties are also discussed.     

Crystal structures of two Ca(II) complexes with imidazole-4,5-dicarboxylate and water ligands

The structure of compound I: poly-diaqua(μ-imidazole-4,5-dicarboxylato-N,O; -O′; -O′′, -O′′′) calcium(II) monohydrate [Ca(C₅H₂N₂O₄)(H₂O)₂·H₂O] is built of molecular sheets in which imidazole-4,5-dicarboxylate ligands bridge the metal ions using both carboxylate groups, each bidentate. Ca(II) is coordinated by six oxygen atoms and one hetero-ring nitrogen atom distributed at the apices of a capped tetragonal bipyramid. The basal plane of the pyramid is formed by two carboxylate oxygen atoms [d(Ca–O2?=?2.374(1)?Å, d(Ca–O4)?=?2.412(1)?Å] and two water oxygen atoms [d(Ca–O5)?=?2.384(1)?Å, d(Ca–O6)?=?2.455(1)?Å], the capped position is occupied by the carboxylate oxygen atom O3 [d(Ca–O3)?=?2.325(1)?Å], the hetero-ring nitrogen atom [d(Ca–N2)?=?2.523(1)?Å] and the carboxylate oxygen atom O4 [d(Ca–O2)?= 2.412(1)?Å] form the apices of the prism. The solvation water molecule plays a significant role in a framework of hydrogen bonds responsible for the stability of the crystal. The structure of compound II: trans-tetraquadi(H-imidazole-4,5-dicarboxylato-N,O) calcium(II) monohydrate, [Ca(C₅H₃N₂O₄)₂(H₂O)₄·H₂O] consists of monomers in which the Ca(II) ion is located on a centre of symmetry. The coordination around the Ca(II) is a strongly deformed pentagonal bipyramidal with the imidazole-4,5-dicarboxylate (4,5-IDA) ligands in the trans arrangement forming a dihedral angle of 68.3°. An imidazole-ring nitrogen atom [d(Ca–N)?=?2.632(2)?Å] and one carboxylate O atom [d(Ca–O)?=?2.531(2)?Å] from each ligand coordinate to the metal ion. The coordination is completed by four water oxygen atoms [d(Ca–O)?=?2.393(2)?Å] and [d(Ca–O)?=?2.367(2)?Å]. The coordinated water molecules act as hydrogen bond donors and acceptors to the unbonded carboxylate oxygen atoms in adjacent monomers giving rise to a three-dimensional molecular network.     

Hydrothermal synthesis,structures and characterization of two new copper(II) triphosphonate compounds

Two copper(II) triphosphonate compounds, Cu[(APTPH₄)(phen)(H₂O)]?·?2.16H₂O (1) and [Cu(APTPH₄)(2,2′-bipy)(H₂O)]?·?2.63H₂O (2), have been prepared by a low temperature hydrothermal reaction from 1-aminopropane-1,1,3-triphosphonic acid (APTPH₆), CuO and a second ligand, phen?=?1,10-phenanthroline, or 2,2′-bipy?=?2,2′-bipyridyl. These two compounds were characterized by single crystal X-ray diffraction, elemental analysis, IR and TG. Crystal data for 1: Monoclinic, space group P2₁ /c, a?=?14.4830(7)?Å, b?=?9.1721(5)?Å, c?=?16.7403(8)?Å, β?=?90.101(2)°. For compound 2: Triclinic, space group P 1, a?=?7.1215(7)?Å, b?=?10.460(2)?Å, c?=?14.671(2)?Å, α?=?82.983(2)°, β?=?83.882(2)°, γ?=?80.617(2)°. In both compounds, each Cu²⁺ ion is five-coordinate with two oxygen atoms from the triphosphonate, two nitrogen atoms from the second ligand and one water molecule, to form a distorted square-pyramidal geometry. Both complexes have 3D supramolecular structures constructed by hydrogen bonds and π–π stacking interactions.     

Preparation,characterization and crystal structures of metal(II) tetraza macrocyclic complexes with organic co-ligands

The complexes [Ni(L1)(pyc)₂]·2H₂O (1) (L1 = C-meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane; Hpyc = pyrazinecarboxylic acid) and [Cu(L2)(H-cpdc)] (2) (L2 = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0^1.18,0^7.12]docosane; H₂-cpdc = cyclopropanedicarboxylic acid) have been synthesized and structurally characterized. The crystal structure of complex 1 shows a distorted octahedral coordination geometry around the nickel(II) center, with four secondary amines in the equatorial positions and two nitrogen atoms of the pyc^? ligands in the trans positions. In complex 2, the coordination environment around the copper(II) center is a Jahn–Teller distorted octahedron with four Cu–N bonds and two axial Cu–O bonds. The electronic spectra, electrochemical and TGA behavior of the complexes are significantly affected by the nature of the axial pyc^? and H-cpdc^? ligands.     

Bis(methanol‐κO)dioxido[3,3′‐(1H‐1,2,4‐triazole‐3,5‐diyl)diphenolato‐κ3O,N4,O′]uranium(VI) methanol monosolvate

The structure of the title compound, [U(C₁₄H₉N₃O₂)O₂(CH₃OH)₂]·CH₃OH, is the first to be reported for an actinide complex including triazole ligands. The U^VI atom exhibits a pentagonal–bipyramidal NO₆ coordination environment, involving two axial oxide ligands [U=O = 1.766 (3) and 1.789 (3) Å], four equatorial O atoms [U—O = 2.269 (3)–2.448 (3) Å] from the ligand and the two coordinated methanol molecules, and one equatorial N atom [U—N = 2.513 (4) Å] from the ligand. In the crystal structure, the complex molecules are linked via intermolecular N—H...O and O—H...O hydrogen bonds to form a two‐dimensional structure.     

Three new binuclear copper(II) complexes with isonicotinic acid N-oxide: syntheses,crystal structures and properties

Three new copper(II) complexes with isonicotinic acid N-oxide (HL) and 1,10-phenanthroline (phen) as ligands, [Cu(L)(phen)(H₂O)]₂(NO₃)₂···2H₂O (1), [Cu(L)(phen)(H₂O)]₂(ClO₄)₂···2H₂O (2), and [Cu(L)(phen)Br]₂- [Cu(L)(phen)(H₂O)]₂Br₂···6H₂O (3) have been synthesized and structurally characterized. The structures of all three complexes feature a Cu₂ dimer formed by two Cu(II) ions interconnected by two bridging ligands. Each copper(II) ion has a distorted square pyramidal coordination geometry with elongated axial coordination by an aqua ligand or halogen anion. The isonicotinic acid N-oxide anion is bidentate, being coordinated to two Cu(II) ions through its N-O oxygen and one of its carboxylate oxygen atoms. Magnetic susceptibility measurements show a Curie–Weiss paramagnetic behavior characteristic of one unpaired electron for a copper(II) ion for all three complexes.     

Synthesis,structure and characterization of copper(II) and zinc(II) complexes based on 3-carboxyl-1,2,4-triazole

Two complexes [CuL₂(H₂O)₂] (1) and [ZnL₂(H₂O)₂] (2) (L?=?3-carboxyl-1,2,4-triazole (L)) have been synthesized and characterized by single-crystal X-ray diffraction analysis. Compound 1 crystallizes in the monoclinic space group P ₂(1)/n, a?=?8.632(8)?Å, b?=?9.153(8)?Å, c?=?6.991(7)?Å, β?=?94.279(12)°, Z?=?2, R ₁?=?0.0296, wR ₂?=?0.0918. Compound 2 also crystallizes in the monoclinic space group P ₂(1)/n, a?=?4.937(3)?Å, b?=?18.107(10)?Å, c?=?6.344(4)?Å, β?=?106.839(7)°, Z?=?2, R ₁?=?0.0230, wR ₂?=?0.0556. Extensive intermolecular hydrogen bonds assemble 1 and 2 into three-dimensional (3D) supramolecular architectures, with eight-member H-bonded synthons. Compounds 1 and 2 were also characterized by element analysis, FT–IR, luminescence and EPR studies.     

Synthesis and crystal structure of mercury(II) chloride–ferron (7-iodo-8-hydroxyquinoline-5-sulfonic acid) adduct

A mercury(II) chloride adduct of ferron (7-iodo-8-hydroxyquinoline-5-sulfonic acid), [HgCl₂ (C₉H₆INO₄)·H₂O] has been synthesized and characterized by X-ray diffraction analysis and spectroscopic studies. The compound crystallizes in P2₁/c space group, a?=?8.919(3), b?=?23.216(3), c?=?7.714(3)?Å, β?=?95.79(3)°. The coordination geometry around mercury is distorted square planar [(2+2) coordination] with two short Hg–Cl bonds [2.308(2) and 2.309(18)?Å] and two long Hg–O(sulfonate) [2.738(4)?Å] and Hg–O(water) [2.889(4)?Å] bonds. The sulfonic group is deprotonated, the proton having migrated to the quinoline N atom that forms intermolecular hydrogen bonds. The inversion related organic ligands are stacked over one another. The crystal structure is further stabilized by a C–H···O, O–H···O and N–H···O hydrogen bonds.     

Mercury(II) complexes containing new ortho-functionalized asymmetric triazene ligands: synthesis,crystal structures,and solution studies

Synthesis of two new asymmetric ligands: 1-(2-ethoxyphenyl)-3-(2-methoxycarbonylphenyl)triazene (HL) (1) and 1-(2-methoxyphenyl)-3-(2-methoxycarbonylphenyl)triazene (HL′) (2) are reported. The prepared triazenes are functionalized by ethoxy and methoxy groups in the ortho positions, respectively. The related monomeric complexes, [HgL₂] (3) and [HgL′₂] (4), were prepared by the reacting of the corresponding ligands with Hg(NO₃)₂ salt in methanol as solvent. All compounds were characterized by CHN analysis, FT-IR, ¹H NMR, and ¹³C NMR spectroscopy. According to the crystal structures of 1 and 2, the N–N bond distances indicate the presence of alternating single and double bonds, and hence the –N=N–NH– moiety. On coordination, each triazene was deprotonated and as a result, a resonance structure is formed between nitrogens which let them to be a tridentate ligand. In the crystal structure of 3, [HgL₂], the central Hg(II) is surrounded by two N atoms from interlocked L forming linear geometry, in which the other four Hg–N and Hg–O bonds are longer and can only be regarded as weak secondary bonds. An interesting feature of 3 is also the presence of π?π [centroid–centroid distance of 3.744(3)?Å] and C–H?π interactions. The results of solution studies for the formation of 3 in methanol support its solid-state stoichiometry.     

Tetra­aqua(5‐fluoro­uracil‐1‐acetato‐O)copper(II) tetra­hydrate

In the title complex, [Cu(C₆H₄FN₂O₄)₂(H₂O)₄]·4H₂O, the Cu atom is located in the centre of a distorted octahedral geometry. The coordination atoms are six O atoms provided by two carboxyl­ate groups [coordinated in a monodentate mode, with Cu—O = 1.9551 (10) Å] and four water mol­ecules [Cu—O = 1.9241 (13) and 2.5771 (14) Å]. In addition, one intramolecular hydrogen bond and ten intermolecular hydrogen bonds make up a three‐dimensional network.     

Crystal structure of (1,10-phenanthroline)ethylenediamine-<Emphasis Type="Italic">N,N′</Emphasis>-diacetatocopper(II) pentahydrate, [Cu(Edda)(Phen)] · 5H<Subscript>2</Subscript>O

The products of oxidation of ethylenediaminetetraacetic acid by manganese dioxide have been used to synthesize crystals of [Cu(Edda)(Phen)] · 5H₂O (Edda is ethylenediamine-N,N′-diacetate, and Phen is 1,10-phenanthroline). The X-ray diffraction analysis of the crystals shows that the N atoms of the Edda and Phen ligands lie in the equatorial plane around the Cu atom, and the O atoms of the Edda ligands are localized in more remote axial positions. The [Cu(Edda)(Phen)] complexes are grouped in pairs at a distance of 3.46 Å between the mean planes of the Phen ligands. Ten water molecules are united by hydrogen bonds into symmetric isolated clusters, and further they form a three-dimensional framework with the [Cu(Edda)(Phen)] complexes.     

Crystal Structures of [Cu2(bpy)2(H2O)(OH)2(SO4)]·4H2O and [Cu(bpy)(H2O)2]SO4 with bpy = 2, 2′‐Bipyridine

Two sulfato Cu^II complexes [Cu₂(bpy)₂(H₂O)(OH)₂(SO₄)]· 4H₂O ( 1 ) and [Cu(bpy)(H₂O)₂]SO₄ ( 2 ) were synthesized and structurally characterized by single crystal X—ray diffraction. Complex 1 consists of the asymmetric dinuclear [Cu₂(bpy)₂(H₂O)(OH)₂(SO₄)] complex molecules and hydrogen bonded H₂O molecules. Within the dinuclear molecules, the Cu atoms are in square pyramidal geometries, where the equatorial sites are occupied by two N atoms of one bpy ligand and two O atoms of different μ₂—OH groups and the apical position by one aqua ligand or one sulfato group. Through intermolecular O—H···O and C—H···O hydrogen bonds and intermolecular π—π stacking interactions, the dinuclear complex molecules are assembled into layers, between which the hydrogen bonded H₂O molecules are located. The Cu atoms in 2 are octahedrally coordinated by two N atoms of one bpy ligand and four O atoms of two H₂O molecules and two sulfato groups with the sulfato O atoms at the trans positions and are bridged by sulfato groups into ¹[Cu(bpy)(H₂O)₂(SO₄)_2/2] chains. Through the interchain π—π stacking interactions and interchain C—H···O hydrogen bonds, the resulting chains are assembled into bi—chains, which are further interlinked into layers by O—H···O hydrogen bonds between adjacent bichains.     

Synthesis,Crystal Structure and Magnetic Properties of Diaqua(1,10-Phenanthroline-N,N')-Hydrogenmaleatocopper(Ii) Hydrogenmaleate Monohydrate

Reaction of freshly-prepared CuCO₃, phenanthroline monohydrate and maleic acid in CH₃OH/H₂O(1 : 1 v/v) at pH=2.13 yielded diaqua(1,10-phenanthroline-N,N')hydrogenmaleatocopper(II) hydrogenmaleate monohydrate, [Cu(phen)(H₂O)₂(C₄H₃O₄)](C₄H₃O₄)(H₂O), which consists of [Cu(phen)(H₂O)₂(C₄H₃O₄)]⁺ complex cations, hydrogenmaleate anions and lattice H₂O molecules. Within the complex cations, the Cu atoms are each square-pyramidally coordinated by two N atoms of one chelating phen ligand and three O atoms of two H₂O molecules and one hydrogenmaleato ligand with one H₂O molecule at the apical position (d(Cu-N) = 2.001, 2.009 Å, equatorial d(Cu-O) = 1.966 Å and axial d(Cu-O) = 2.235 Å). Through hydrogen bonding, the complex cations, hydrogenmaleate anions and lattice H₂O molecules are assembled into 1D chains, which are held together by weak Cu···O interactions (3.139 Å) to form corrugated 2D layers. Significant π-π stacking interactions between neighboring phen ligands leads to supramolecular assembly of the 2D layers. Over the temperature range 5-300 K, the complex obeys the Currie-Weiss law with an effective magnetic moment of 1.78 BM at room temperature.     

trans‐Bis(benzoato‐O)tetrakis(methanol‐O)iron(II): ligand bulk is not structure‐determining

The title compound, [Fe(C₇H₅O₂)₂(CH₄O)₄], is a centrosymmetric six‐coordinate Fe^II complex coordinated by two axial monodentate benzoate ligands and four methanol ligands in the equatorial plane [Fe—O_benzoate 2.0935 (7) Å, and Fe—O_methanol 2.1310 (7) and 2.1290 (7) Å]. The benzoate ligands adopt monodentate ligation, rather than a bridged polymeric structure, because of strong intra‐ and intermolecular hydrogen bonds to the methanol ligands. This structure is nearly identical to that obtained with a much bulkier carboxyl­ate ligand [Chavez, Que & Tolman (2001). Chem. Commun. pp. 111–112].     

Bis(hinokitiolato)copper(II): modification (III)

Bis(hinokitiolato)copper(II), Cu(hino)₂, exhibits both antibacterial and antiviral properties, and has been previously shown to exist in two modifications. A third modification has now been confirmed, namely tetrakis(μ₂‐3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)bis(3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)tricopper(II)–bis(μ₂‐3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)bis[(3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olato)copper(II)] (1/1), [Cu(C₁₀H₁₁O₂)₂]₃·[Cu(C₁₀H₁₁O₂)₂]₂, where 3‐isopropyl‐7‐oxocyclohepta‐1,3,5‐trien‐1‐olate is the systematic name for the hinokitiolate anion. This new modification is composed of discrete [cis‐Cu(hino)₂]₂[trans‐Cu(hino)₂] trimers and [cis‐Cu(hino)₂]₂ dimers. The Cu atoms are bridged by μ₂‐O atoms from the hinokitiolate ligands to give distorted square‐pyramidal and distorted octahedral Cu^II coordination environments. Hence, the Cu^II environments are CuO₅/CuO₆/CuO₅ for the trimer and CuO₅/CuO₅ for the dimer. Each trimer and dimer has crystallographically imposed inversion symmetry. The trimer has never been observed before, the dimer has been seen only once before, and the combination of the two together in the same lattice is unprecedented. The CuO₅ cores exhibit four strong basal Cu—O bonds [1.915 (2)–1.931 (2) Å] and one weak apical Cu—O bond [2.652 (2)–2.658 (2) Å]. The CuO₆ core exhibits four strong equatorial Cu—O bonds [1.922 (2)–1.929 (2) Å] and two very weak axial Cu—O bonds [2.911 (3) Å]. The bite angles for the chelating hinokitiolate ligands range from 83.13 (11) to 83.90 (10)°.     

Synthesis,crystal structure,spectroscopy, and nuclease activity of copper(II) complexes containing N,N-bis(2-pyridylmethyl)amine ligand

[Cu(bpea)Cl]ClO₄ (1) and a new copper(II) complex [Cu(bpma)(Ph-COO)(H₂O)]ClO₄ (2) [bpea?=?N,N-bis(2-pyridylmethyl)ethylamine; bpma?=?N,N-bis(2-pyridylmethyl)methylamine] have been synthesized. Complex 2 was crystallized in monoclinic space group P2₁/c with unit cell parameters a ?=?16.460(6)?Å, b ?=?11.222(4)?Å, c?=?12.522(5)?Å, and β?=?97.985(6)°. Interactions of the complexes with calf thymus DNA (CT-DNA) have been investigated by UV absorption, fluorescence, and cyclic voltammetry; thus, modes of CT-DNA binding for the complexes have been proposed. Furthermore, DNA cleavage activities by the complexes were performed in the absence of any external agents. The influence of complex concentration or reaction time on the DNA cleavage was studied.     

(1,3‐Dimethylimidazolidine‐2‐selone‐κSe)bis(1,10‐phenanthroline‐κ2N,N′)copper(II) bis(perchlorate) and bis(2,2′‐bipyridyl‐κ2N,N′)(imidazolidine‐2‐thione‐κS)copper(II) bis(perchlorate)

In the first title salt, [Cu(C₁₂H₈N₂)₂(C₅H₁₀N₂Se)](ClO₄)₂, the Cu^II centre occupies a distorted trigonal–bipyramidal environment defined by four N donors from two 1,10‐phenanthroline (phen) ligands and by the Se donor of a 1,3‐dimethylimidazolidine‐2‐selone ligand, with the equatorial plane defined by the Se and by two N donors from different phen ligands and the axial sites occupied by the two remaining N donors, one from each phen ligand. The Cu—N distances span the range 1.980 (10)–2.114 (11) Å and the Cu—Se distance is 2.491 (3) Å. Intermolecular π–π contacts between imidazolidine rings and the central rings of phen ligands generate chains of cations. In the second salt, [Cu(C₁₀H₈N₂)₂(C₃H₆N₂S)](ClO₄)₂, the Cu^II centre occupies a similar distorted trigonal–bipyramidal environment comprising four N donors from two 2,2′‐bipyridyl (bipy) ligands and an S donor from an imidazolidine‐2‐thione ligand. The equatorial plane is defined by the S donor and two N donors from different bipy ligands. The Cu—N distances span the range 1.984 (6)–2.069 (7) Å and the Cu—S distance is 2.366 (3) Å. Intermolecular π–π contacts between imidazolidine and pyridyl rings form chains of cations. A major difference between the two structures is due to the presence in the second complex of two N—H...O hydrogen bonds linking the imidazolidine N—H hydrogen‐bond donors to perchlorate O‐atom acceptors.     

Bis(2‐chloro‐5‐methylpyridine‐κN)bis(nitrato‐κ2O,O′)copper(II)

In the molecule of the title compound, [Cu(NO₃)₂(C₆H₆ClN)₂], the Cu atom lies on an inversion centre and is six‐coordinated by two pyridine N atoms and four nitrate O atoms in trans positions. The nitrate acts as an unsymmetrical bidentate ligand. The coordination geometry is octahedral, with the Cu—N and the two Cu—O distances being 1.9939 (16), 2.0246 (16) and 2.4866 (19) Å, respectively. There are five types of C—H⋯O hydrogen bonds. Two of these generate two‐dimensional molecular networks in the direction of the a axis, and the others connect adjacent molecular networks.     

Two‐dimensional square‐grid frameworks formed by self‐associating copper(II) complexes with 1‐(3‐pyridyl)‐ and 1‐(4‐pyridyl)‐substituted butane‐1,3‐diones

In bis­[1‐(3‐pyridyl)butane‐1,3‐dionato]copper(II) (the Cu atom occupies a centre of inversion), [Cu(C₉H₈NO₂)₂], (I), and bis­[1‐(4‐pyridyl)butane‐1,3‐dionato]copper(II) methanol solvate, [Cu(C₉H₈NO₂)₂]·CH₃OH, (II), the O,O′‐chelating diketonate ligands support square‐planar coordination of the metal ions [Cu—O = 1.948 (1)–1.965 (1) Å]. Weaker Cu⋯N inter­actions [2.405 (2)–2.499 (2) Å], at both axial sides, occur between symmetry‐related bis­(1‐pyridylbutane‐1,3‐dion­ato)copper(II) mol­ecules. This causes their self‐organization into two‐dimensional square‐grid frameworks, with uniform [6.48 Å for (I)] or alternating [4.72 and 6.66 Å for (II)] inter­layer separations. Guest methanol mol­ecules in (II) reside between the distal layers and form weak hydrogen bonds to coordinated O atoms [O⋯O = 3.018 (4) Å].     

Synthesis,Crystal Structure and Spectroscopic Properties of [2,13‐Bis(1‐naphthalenylmethyl)‐5,16‐dimethyl‐2,6,13,17‐tetraazatricyclo(14,4,01.18,07.12)docosane]copper(II) Diperchlorate Acetonitrile Disolvate

The N‐functionalized macrocyclic ligand 2,13‐bis(1‐naphthalenylmethyl)‐5,16‐dimethyl‐2,6,13,17‐tetraazatricyclo(14,4,0^1.18,0^7.12)docosane (L³) and its copper(II) complex were prepared. The crystal structure of [Cu(L³)](ClO₄)₂·2CH₃CN was determined by single‐crystal X‐ray diffraction at 150 K. The copper atom, which lies on an inversion centre, has a square planar arrangement and the complex adopts a stable trans‐III configuration. The longer distance [2.081(2) Å] for Cu–N(tertiary) compared to 2.030(3) Å for Cu–N(secondary) may be due to the steric effect of the attached naphthalenylmethyl group on the tertiary nitrogen atom. Two perchlorate ions are weakly attached to copper in axial sites and are further connected to the ligand of the cation through NH ··· O hydrogen bonds [N ··· O 3.098 Å]. IR and UV/Vis spectroscopic properties are also described.