Reactions Of CuX Research Articles

Synthesis of copper(II) halide dimers with 2-amino-5-methylpyridine and serendipitous copper catalyzed synthesis of 3-bromo-2-ethyl-5-methyl-1H-pyrrolo[2,3-b]pyridine

Reaction of CuX2·nH2O (X = Cl, n = 2; X = Br, n = 0) with 2-amino-5-methylpyridine (5MAP) in acetonitrile yielded [(5MAP)2CuX2]2 (1, Cl; 2, Br). The compounds are isomorphous and crystallize in the monoclinic space group P21 /n as bihalide bridged dimers. Variable temperature magnetic measurements show very weak exchange in the two compounds (-2.1(1) K) which may correlate with previously proposed magnetostructural correlations for bihalide bridged Cu(II) dimers. In attempts to prepare 2 in 2-butanone as solvent, [(3-Br-2-Et-5-Mepyrpy)(CH3CO2)4Cu2] (3) was serendipitously isolated (3-Br-2-Et-5-Mepyrpy = 3-bromo-2-ethyl-5-methyl-7H-pyrrolido[2,3-b]pyridinium). The bicyclic ligand was synthesized in situ by condensation of 5MAP with the solvent; the acetate ions were generated by copper(II) catalyzed Baeyer-Villiger oxidation of the solvent. A mechanism for the synthesis is proposed. The resulting Cu-paddlewheel compound exhibits strong (-400 K) antiferromagnetic interactions.

Mononuclear copper(I) complexes bearing a 3-phenyl-5-(pyridin-4-yl)-1,2,4-triazole ligand: synthesis, crystal structure, TADF-luminescence, and mechanochromic effects.

Three new mononuclear heteroleptic copper(I) halide complexes, [CuL(PPh3)2X] (X = Cl, Br, I), based on 3-phenyl-5-(pyridin-4-yl)-1,2,4-triazole (L) and triphenylphosphine (PPh3) ligands, have been prepared by reaction of CuX (X = Cl, Br, I), L and PPh3 in a molar ratio of 1 : 1 : 2 in MeCN solutions. The synthesized complexes exhibit blue light emission in solutions and bright green emission in the crystal state with quantum yields of up to 100%. The luminescence decay analysis and density functional theory calculations revealed that the emission of solid samples at room temperature corresponds to the thermally activated delayed fluorescence, while that at 77 K is assigned to phosphorescence. Utilizing the studied complexes in OLED heterostructures resulted in high-performing green-emitting devices with an external quantum efficiency of up to 13.4%.

The tendency of the charge transfer system, derived from chloranilic acid and 2-amino-2-(hydroxymethyl)-1,3-propanediol towards copper(II) complex-formation: characterization, anion impact, and biological studies

Six new copper (II) complexes from the reaction of Cu X2, X = NO3−, Cl− or OAc− with the charge transfer complex [(CLA)2(THAM)2(H2O)] (CT) derived from 1:1 reaction between chloranilic acid (CLA) and 2-amino-2-(hydroxymethyl)-1,3-propanediol (THAM) were isolated and characterized. The nature of products was found to be anion and mole ratio-dependent. The physicochemical characterization of the products showed the formation of two sets of complexes, 2:1 and 1:1 of Cu(II): CT -mole ratios, giving binuclear and mononuclear copper(II) complexes, respectively. The different spectral results showed that complexes, [Cu2(CLA)(THAM)2(H2O)4], 1, [Cu2(CLA)(THAM)2(H2O)4]·H2O, 2 and [Cu2(CLA)(THAM)2(CH3COO)2(H2O)2], 3, are of elongated, distorted octahedral structures, complexes [Cu(CLA)(THAM)(NO3)], 4, and [Cu(CLA)(THAM)Cl], 5, are distorted square planner, while [Cu(CLA)(THAM)(CH3COO)(H2O)], 6, is compressed distorted octahedral structure. Applying thermal analysis techniques (TG and DTA), Cu(II) complexes exhibited high thermal stability, with high activation energy, Ea = (89.3–659.7) JK−1mol−1. The thermal decomposition showed exothermic behavior, ∆Ho = [(-75.9)-(-230.4)] kJmol−1, and more ordered transition states, ∆So = [(-0.20)-(-0.22)] kJK−1mol−1. The CT-complex and its Cu(II) complexes have been tested versus some pathogenic bacterial and fungal species, showing considerable activity, in the order; [(CLA)2(THAM)2(H2O)], (CT) > [Cu(CLA)(THAM)(NO3)], 4 > [Cu2(CLA)(THAM)2(H2O)4],1 ≈ [Cu(CLA)(THAM)(CH3COO)(H2O)], 6 ≈ [Cu2(CLA)(THAM)2(CH3COO)2(H2O)2], 3 ≈ [Cu(CLA)(THAM)Cl], 5 ≈ [Cu2(CLA)(THAM)2(H2O)4]·H2O, 2. Moreover, the in vitro cytotoxic activity test versus the breast cancer cell (MCF7), showing promising results.

Synthesis, characterization, and photophysical properties of a new 2,5-di(aryl)phosphole derivative and their trigonal copper–phosphole complexes

A new phosphole derivative, 2,5-di(2-quinolyl)-1-phenylphosphole (1), was synthesized by using the Fagan–Nugent method. Phosphole 1 was obtained as an air-stable solid in high yield (73%). Additionally, two new copper–phosphole complexes, [CuX(Phosphole)2] (X = Cl (2a), I (2b), Phosphole=1), have been synthesized by reaction of CuX (X = Cl, I) and 1. All compounds were characterized by NMR, ESI-MS, UV–Vis, and fluorescence spectroscopy. The photophysical properties of all compounds were analyzed. UV–Vis spectra of 2a-b show π–π* transitions with shifts very similar to the free phosphole due to that their symmetrical structures inhibiting an efficient intraligand charge transfer, ILCT. Compounds 1, 2a-b exhibit fluorescence between 460 and 583 nm with quantum yields of Φf =0.04 − 0.11. The emission energy of 2b is higher than 2a, suggesting that λ max is affected by the ligand-field strength of the halide in the complexes (I¯ < Cl¯). The suggested structures of 2a-b were analyzed computationally at the PBEPBE/def2svp level of theory. The rotation barrier of the quinolyl group was analyzed by a scan analysis. Then, the 3 D structures of 2a-b were obtained in good agreement with the experimental results.

Design and construction of the imidazole-2-thione-based copper(I) complexes by varying the co-anion and synthesis conditions and verifying their antimicrobial activity

A series of copper-based polymers of [Cu(bbit)I]n (1), {[Cu(bbit)2](HSO4).(S8)0.5}n (2), [Cu4(CN)4 (bbit)2]n (3) and [Cu(bbit)Cl]n (4) have been designed and synthesized from reaction of CuX (X ​= ​I, Cl and CN) with 1,1-(1,4-butanediyl) bis (1,3-dihydro-3-methyl-1H-imidazole- 2-thione) (bbit) ligand. These compounds were characterized by IR, CHNS, PL, TGA, PXRD and their crystal structures were determined by X-ray crystallography. The final structure of synthesized polymers was affected by applied co-ligand and reaction conditions. Treating copper(I) iodide with equimolar ratio of bbit ligand afforded 1D wavelike polymer 1 with a distorted trigonal planar geometry by branched tube method. Polymer 2 has synthesized by the same starting material for 1 through unexpected process by solvothermal method with a distorted S4 tetrahedral environment. With addition of CN− to the reaction mixture of 1, 2D wavelike polymer of 3 with distorted trigonal CNS and tetrahedral CNS2 coordination environments was formed. Polymer 4 is analogue of 1 and was prepared by the same method as for 1 using copper chloride instead of copper iodide. The action of the title polymers on several pathogens were verified via antibacterial, MIC and MBC tests. The obtained results displayed that the polymers 1, 2 and 4 have bactericidal behavior, while the polymer 3 is a bacteriostatic agent.

Dinuclear Cu(I) Halides with Terphenyl Phosphines: Synthesis, Photophysical Studies, and Catalytic Applications in CuAAC Reactions.

Several dinuclear terphenyl phosphine copper(I) halide complexes of composition [CuX(PR2Ar')]2 (X = Cl, Br, I; R = hydrocarbyl, Ar' = 2,6-diarylterphenyl radical), 1-5, have been isolated from the reaction of CuX with 1 equiv of the phosphine ligand. Most of them have been characterized by X-ray diffraction studies in the solid state, thus allowing comparative discussions of different structural parameters, namely, Cu···Cu and Cu···Aryl separations, conformations adopted by coordinated phosphines, and planarity of the Cu2X2 cores. Centrosymmetric complexes [CuI(PMe2ArXyl2)]2, 1c, and [CuI(PEt2ArMes2)]2, 3c, despite their similar structures, show very distinct photoluminescence (PL) in powder form at room temperature. The photophysical behavior of these compounds in liquid solution, solid-solid Zeonex solution and powder samples at room temperature and 77 K have been investigated and supported by DFT calculation. Identification of vibronic coupling modes, done by group theory calculations and the technique of projection operators, shows that the manifestation of these modes is conditioned by crystal packing. Complexes [CuI(PMe2ArXyl2)]2, 1c, and [CuI(PEt2ArMes2)]2, 3c, display remarkable activity in copper-catalyzed azide-alkyne cycloaddition reactions involving preformed and in situ-made azides. Reactions are performed in H2O, under aerobic conditions, with low catalyst loadings and tolerate the use of iodoalkynes as substrates.

Structural diversity of copper(I) cyclodiene complexes bridged by 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine

The reactions of CuX2·nH2O (X=ClO4, BF4), Cu turnings and 3,6-bis(2-pyridyl)-1,2,4,5-tetrazine (bptz) with excess 1,5-cyclooctadiene (cod) in Me2CO under C2H4 afforded dinuclear Cu(I)-bptz/η2,η2-cod-X complexes {(1) and (4)} and dinuclear Cu(I)-2,5-H2bptz/η2,η2-cod-X complexes {(2) and (5)}. In complexes 1 and 4, each Cu(I) atom is coordinated by two chelate N atoms of bptz and two CC bonds of η2,η2-cod in the distorted tetrahedral geometry to produce a transoid dinuclear structure. It should be noted that the redox state of the central tetrazine ring is electrochemically neutral. In complexes 2 and 5, each Cu(I) atom is coordinated by two chelate N atoms of 2,5-H2bptz and two CC bonds of η2,η2-cod in the distorted tetrahedral geometry to afford a transoid dinuclear structure in the 2,5-dihydro form. In contrast, the reactions of Cu(BF4)2·nH2O, Cu turnings and bptz with excess 2,5-norbornadiene (nbd) in MeEtCO under C2H4 afforded Cu(I)-2,5-H2bptz/η2-nbd-BF4 complex (6). Each Cu(I) atom is coordinated by two chelate N atoms in bptz and one CC bond in η2-nbd to form a transoid dinuclear structure in the 2,5-dihydro form. These facts show that the flexible cod can preferentially produce a Cu(I)-cyclodiene complex in the η2,η2-mode (complexes 1, 2, 4 and 5) while the rigid nbd can produce a Cu(I)-cyclodiene complex in the η2-mode (complex 6). Furthermore, the reaction of Cu(NO3)2·3H2O, Cu turnings and bptz with excess nbd in Me2CO under C2H4 afforded tetranuclear Cu(I)-4,5-H2bptz-NO3 complex (7) containing a unique anionic [Cu2(nbd)(NO3)4]2− moiety. In the cationic [Cu4(4,5-H2bptz)4]4+ moiety, four Cu(I) atoms are bridged by four 4,5-H2bptz ligands to form a [4×4] grid-like tetranuclear structure with two 4,5-H2bptz ligands lying above the Cu4 mean plane and two lying below. In the anionic [Cu2(nbd)(NO3)4]2− moiety, the two Cu atoms are bridged by one nbd ligand in the μ2-η2,η2-mode.

CuX (X = I, Br and Cl) based coordination polymers of azino-pyridyl ligand and PPh3: Structural, spectral, electro-chemical, and DFT studies

Three new copper(I) coordination polymers [Cu2(µ-L)(µ-I)2)(PPh3)2]n (1), [Cu2(µ-L) (µ-Br)2(PPh3)2]n (2) and [Cu2(µ-L)(µ-Cl)2(PPh3)2.CH3CN]n (3) have been synthesized by reactions of CuX (X=I, Br and Cl) with PPh3 and the polydentate azino-pyridyl ligand L. These complexes have been characterized by elemental analyses, IR, UV–Vis and NMR spectroscopy. The crystal structures of the complexes 1 and 3 have been determined by single-crystal X-ray analysis and it has been found that these are 1-D co-ordination polymers containing bridged halide ions as well as the azino-pyridyl ligand L. Matching of X-ray powder patterns and theoretical studies reveal that the complex 2 is also a 1-D co-ordination polymer. The ligand L is non-emissive at room temperature in dichloromethane, whereas the complexes 1, 2 and 3 are photoluminescent. The E1/2 values of the CuI-CuII couple for 1, 2 and 3 are within 0.75–0.80 (vs. Ag/AgCl in 1M KCl, scan rate 100mVs−1. DFT and Hirshfeld surface studies have also been performed for 1, 2 and 3.

Cis-1,2-Bis(diphenylphosphino)ethylene copper(i) catalyzed C–H activation and carboxylation of terminal alkynes

Reaction of CuX (X = CN, SCN) and cis-1,2-bis(diphenylphosphino)ethylene (dppet) in 1 : 1 molar ratio in DCM–MeOH (50 : 50 V/V) afforded copper(i) complexes. These complexes were shown to be efficient catalysts in comparison to CuCN/CuSCN for the conversion of terminal alkynes into propiolic acids with CO2 at room temperature.

Steric effects of catalysts and substrates on catechol oxidation catalysis: Cyclodimeric copper(II) complexes containing 1,4-bis(dimethyl(quinolin-3-yl)silyl)benzene

Reaction of CuX2 with new ligand, 1,4-bis(dimethyl(quinolin-3-yl)silyl)benzene (L), in alcohol affords C2-symmetric double-alkoxy-supported cyclodimeric copper(II) complexes, [Cu(μ-OR)(L)]2(X)2 (R=Me, Et, iPr; X−=ClO4−, BF4−) in high yields. These cyclodimeric species with intracyclic Cu⋯Cu distances of 2.92–2.98Å show the significant catalytic effects on the catechol oxidation catalysis in chloroform in the order [Cu(μ-OMe)(L)]2(X)2>[Cu(μ-OEt)(L)]2(X)2>[Cu(μ-OiPr)(L)]2(X)2. Furthermore, the catalytic efficiency is strongly substrate-dependent in the order 4-BuCat>4-ClCat>3,5-DBuCat>Cat. Such notable catalytic effects potentially can be explained by the steric hindrance of both catalysts and substrates.

Mo(W)/Cu/S coordination polymers based on tetranuclear cubane-like cluster nodes and 1,4-bis(3,5-dimethypyrazol-1-yl)butane flexible ligand

Three new coordination compounds {[MoOS3Cu3I(bbd)1.5]·2DMF}n (1), {[MoS4Cu3Br(bbd)1.5]·MeOH·2H2O}n (2) and {[WS4Cu3Br(bbd)1.5]·DMF}n (3), incorporating tetranuclear cubane-like cluster units, have been prepared under ambient conditions in DMF by the reaction of CuX (X=Br, I) and (NH4)2[MXS3] (M=Mo, W; X=S, O) with a flexible linker ligand, 1,4-bis(3,5-dimethypyrazol-1-yl)butane (bbd). The complexes have been characterized by elemental analyses, IR and UV–Vis spectroscopy. Single-crystal X-ray structure determinations of 1 and 2 have also been undertaken. In the polymeric structures of 1 and 2, two inorganic tetranuclearcubane-like fragments [MoOS3Cu3I] (in 1) and [MoS4Cu3Br] (in 2) are linked by a pair of μ-bbd ligands to form 22-membered rings. In both polymers, the double-cluster/double-bridge units are further linked by a single μ-bbd ligand to generate polymeric chains. In 1 and 2 the Cu atoms possess a distorted tetrahedral geometry formed by an S2NX donor atom set (X=I in 1 and X=Br in 2). In 1, adjacent chains are stabilized by intermolecular C–H⋯π interactions.

Synthesis and Reactions of 3d Metal Complexes with the Bulky Alkoxide Ligand [OC(t)Bu2Ph

Treatment of NiCl2(dme) and NiBr2(dme) (dme = dimethoxyethane) with 2 equiv of LiOR (OR = OC(t)Bu2Ph) forms the distorted trigonal planar complexes [NiLiX(OR)2(THF)2] (THF = tetrahydrofuran) 5 (X = Cl) and 6 (X = Br). The reaction of CuX2 (X = Cl, Br) with 2 equiv of LiOR affords the Cu(I) product Cu4(OR)4 (7). The same product can be obtained using the Cu(I) starting material CuCl. NMR studies indicated that the reduction of Cu(II) to Cu(I) is accompanied by the oxidation of the alkoxide RO(-) to form the alkoxy radical RO(•), which subsequently forms tert-butyl phenyl ketone by β-scission. Treatment of compounds 1-4 ([M2Li2Cl2(OR)4], M = Cr-Co) with thallium hexafluorophosphate allowed the isolation of the distorted tetrahedral complexes of the form M(OR)2(THF)2 for M = Mn (8), Fe (9), and Co (10). Cyclic voltammetry performed on compounds 8-10 demonstrated irreversible oxidations for all complexes, with the iron complex 9 being the most reducing. Complex 9 shows a reactivity toward PhIO and Ph3SbS to form the corresponding dinuclear iron(III) complexes Fe2(O)(OR)4(THF)2 (11) and Fe2(S)(OR)4(THF)2 (12), respectively. X-ray structural studies were performed, showing that the Fe-O-Fe angle for complex 11 is 176.4(1)° and that the Fe-S-Fe angle for complex 12 is 164.83(3)°.

Photoluminescent mixed ligand complexes of CuX (X = Cl, Br, I) with PPh3 and a polydentate imino-pyridyl ligand – Syntheses, structural variations and catalytic property

Three ternary copper(I) complexes [CuI2Cl2(L1)(PPh3)4] (1), [CuI2Br2(L1) (PPh3)4] (2) and [CuI2(μ-I)2 (μ-L1) (PPh3)2]n (3) have been prepared by reactions of CuX (X=Cl, Br and I) with PPh3 and the polydentate imino-pyridyl ligand L1. These complexes have been characterized by elemental analysis, IR, UV–Vis, NMR and X-ray crystallography. From single crystal structural analysis it has been found that complexes 1 and 2 are homo-dinuclear having non-bridging halide ions whereas complex 3 is a 1-D zig-zag co-ordination polymer containing bridged iodide ions. Complexes 1, 2 and 3 are photoluminescent at room temperature in chloroform whereas ligand L1 is non-emissive. The E½ values of the CuICuII couple of 1, 2 and 3 are 0.98V, 0.92V and 0.42V respectively (vs Ag/AgCl in 1M KCl, scan rate 100mVs−1). All three complexes function as effective catalysts for the synthesis of 2-substituted benzoxazoles.

Copper(I) and silver(I) complexes containing the enantiopure N,N-bidentate 1,3-bis[4′-(S)-isopropyloxazolin-2′-yl]benzene ((S,S)-iPr-pheboxH) ligand

The reaction of CuX (X=I, Br, Cl) with (S,S)-iPr-pheboxH=1,3-bis[4′-(S)-isopropyloxazolin-2′-yl]benzene in 2:1 molar ratio allows us to synthesize tetranuclear complexes [Cu4X4(к2-N,N-iPr-pheboxH)2] (X=Cl (1), Br (2), I (3)). The polymeric species [Cu4I4(κ2-N,N-iPr-pheboxH)2]n (4) has been prepared by reaction of CuI with (S,S)-iPr-pheboxH in 1.5:1 molar ratio. Also, polymeric silver species {[Ag(κ2-N,N-iPr-pheboxH)][X]}n (X=CF3SO3 (7a), SbF6 (7b), PF6 (7c)) have been synthesized by reaction of the corresponding silver salt and (S,S)-iPr-pheboxH in 1:1 molar ratio. The structures of the tetranuclear complexes 1–3 as well as of the polymeric species [Cu4I4(κ2-N,N-iPr-pheboxH)2]n (4) and {[Ag(κ2-N,N-iPr-pheboxH)][PF6]}n (7c) have been determined by single crystal X-ray analysis.

1,1'-Bis(di-tert-butylphosphino)ferrocene copper(I) complex catalyzed C-H activation and carboxylation of terminal alkynes.

Four copper(i) complexes, [CuBr(dtbpf)] (1), [CuI(dtbpf)] (2), [Cu4(μ2-I)2(μ3-I)2(μ-dtbpf)2] (3) and [Cu6(μ3-I)6(μ-dtbpf)2]·2CH3CN (4), were prepared using CuX (X = Br, I) and 1,1'-bis(di-tert-butylphosphino)ferrocene (dtbpf). These complexes have been characterized by elemental analyses, IR, (1)H and (31)P NMR, ESI-MS and electronic absorption spectroscopy. Molecular structures of the complexes 2 and 4 were determined crystallographically. Complex 2 is the first monomeric isolated Cu(i) complex of dtbpf with the largest P-Cu-P bite angle (120.070(19)°) to date. Complex 4 shows a centrosymmetrical dimeric unit with two [Cu3(μ3-I)3] motifs bridged by two bidentate dtbpf ligands in the κ(1)-manner. Each [Cu3(μ3-I)3] motif unites to form a pyramid with one copper atom at the apex and one of the triangular faces capped by an iodine atom. All the complexes were found to be efficient catalysts for the conversion of terminal alkynes into propiolic acids with CO2. Owing to the excellent catalytic activity, the reactions proceeded at atmospheric pressure and ambient temperature (25 °C). The catalytic products were obtained in moderate to good yields (80-96%) by using complex loading to 2 mol%. To the best of our knowledge, this is the first example of an active ferrocenyl diphosphine Cu(i) catalyst for the carboxylation of terminal alkynes with CO2.

New topological 3D copper(ii) coordination networks: catechol oxidation catalysis and solvent adsorption via porous properties

The reaction of CuX2 (X− = ClO4− and BF4−) with a new 1,3,5-tris(isonicotinoyloxymethyl)benzene (L) ligand gives rise to 3D coordination networks, [Cu3L4(CH3CN)6](X)6, with a new topology of the Schläfli point symbol {4·82}4{42·82·102}2{84·122}. [Cu3L4(CH3CN)6](ClO4)6 and [Cu3L4(CH3CN)6](BF4)6 networks have useful oval-shaped pores of 11.2 × 11.2 × 24.8 Å3 and 11.1 × 11.1 × 24.4 Å3 dimensions, respectively. These porous coordination networks act as good heterogeneous catalysts, oxidizing the catechols in the order 3,5-di-tert-butylcatechol (3,5-DBuCat) > 4-tert-butylcatechol (4-BuCat) > 4-chlorocatechol (4-ClCat). The catalytic effect of [Cu3L4(CH3CN)6](BF4)6 is slightly higher than that of [Cu3L4(CH3CN)6](ClO4)6. The pores of the 3D networks reversibly adsorb the solvents in the order chloroform > tetrahydrofuran > acetone.

Synthesis, structure, redox properties and theoretical calculation of copper(I)-triphenylphosphine halide complexes of arylazopyridines, and their reaction with H2O2

Reaction of CuX (X=Cl, Br, I), PPh3 and 2-(arylazo)pyridine, R-H4C6NNC5H4N (aap, 1 where R=H (pap), p-Me (p-tap), m-Me (m-tap)) has synthesized [Cu((aap)(PPh3)X]. The structure has been established by spectroscopic (UV–Vis, 1H NMR) data and by single crystal X-ray diffraction of [Cu((pap)(PPh3)Br]. Addition of H2O2 to [Cu((aap)(PPh3)Cl] has afforded blue Cu(II) complexes, [Cu(aapO)(PPh3)Cl]. These complexes have been characterized by elemental analyses, IR, UV–Vis spectral and magnetic data. Upon addition of H2S saturated dil. H2SO4 solution to [Cu(aapO)(PPh3)Cl] free aapOH is separated and has been characterized by spectral data. Cyclic voltammogram of [Cu((aap)(PPh3)X] shows Cu(II)/Cu(I) response at 1.00–1.15V and azo reduction at negative to SCE. DFT calculation of optimized structure of a representative complex has been used to determine the composition and energy of molecular levels and data have been used to explain the electronic spectral and redox properties.

Tuning the framework formation of copper coordination compounds by using neutral bi and tetradentate flexible pyrazole-based ligands

Two new coordination compounds, [Cu(μ-bbd)(NCS)2]n (1) and [Cu2Cl4(μ-tdmpp)(H2O)2] (2), were prepared at room temperature by the reaction of CuX2 (X=Cl, SCN) salts with the flexible linker ligands 1,4-bis(3,5-dimethypyrazol-1-yl)butane (bbd) and 1,1,3,3-tetrakis(3,5-dimethypyrazol-1-yl)propane (tdmpp). The complexes were characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. In the polymeric structure of 1, the copper(II) ion lies on a center of symmetry within a square-planar trans-CuN4 coordination geometry. The NCS groups are terminally N-bonded to the metal center and the μ-bbd ligand, with a gauche-anti-gauche conformation, acts as a centrosymmetric bridging bidentate ligand, linking the Cu(II) centers into a one-dimensional zigzag chain structure. In contrast to 1, complex 2 has a dinuclear structure in which each of the copper(II) ions is five-coordinated in a distorted CuN2Cl2O square-based pyramidal coordination geometry. The neighboring discrete [Cu2Cl4(μ-tdmpp).(H2O)2] molecules are connected by intermolecular O–H⋯Cl hydrogen bonds to form an infinite chain of neutral molecules. The adjacent 1D chains of complex 2 are further extended into a non-covalent 3D network structure by C–H⋯O intermolecular hydrogen bonds. The polymeric structure of [Cu(CH3CN)(μ3-SCN)]n (3) was obtained as an unexpected product in an attempt to synthesize the [Cu(μ-bpp)(SCN)2]n polymer in acetonitrile solution.

Semiconductive and Magnetic One-Dimensional Coordination Polymers of Cu(II) with Modified Nucleobases

Four new copper(II) coordination complexes, obtained by reaction of CuX2 (X = acetate or chloride) with thymine-1-acetic acid and uracil-1-propionic acid as ligands, of formulas [Cu(TAcO)2(H2O)4]·4H2O (1), [Cu(TAcO)2(H2O)2]n (2), [Cu3(TAcO)4(H2O)2(OH)2]n·4H2O (3), and [Cu3(UPrO)2Cl2(OH)2(H2O)2]n (4) (TAcOH = thymine-1-acetic acid, UPrOH = uracil-1-propionic acid) are described. While 1 is a discrete complex, 2-4 are one-dimensional coordination polymers. Complexes 2-4 present dc conductivity values between 10(-6) and 10(-9) S/cm(-1). The magnetic behavior of complex 2 is typical for almost isolated Cu(II) metal centers. Moderate-weak antiferromagnetic interactions have been found in complex 3, whereas a combination of strong and weak antiferromagnetic interactions have been found in complex 4. Quantum computational calculations have been done to estimate the individual "J" magnetic coupling constant for each superexchange pathway in complexes 3 and 4. Compounds 2-4 are the first known examples of semiconductor and magnetic coordination polymers containing nucleobases.

Copper(I) halide complexes of N-methylbenzothiazole-2-thione: Synthesis, structure, luminescence, antibacterial activity and interaction with DNA

The reactions of copper(I) halides, CuX (X=Cl, Br, I) with N-methylbenzothiazole-2-thione (mbtt), independent of the molar ration chosen (1:2 or 1:3), led to the formation of dinuclear complexes of the formula [CuX(mbtt)2]2, whereas the reactions of CuX and mbtt in the presence of two equivalents of triphenylphosphine (PPh3) afforded mononuclear mixed-ligand complexes of the formula [CuX(PPh3)2(mbtt)]. The molecular structure of a representative compound from each of the two above types of complexes, namely [CuCl(mbtt)2]2 and [CuI(PPh3)2(mbtt)] have been established by single-crystal X-ray diffraction. The new complexes are strongly emissive both in the solid state and in solution. The complexes were also screened for antibacterial activity and their ability to interact with native calf thymus DNA (CT-DNA) in vitro. Both types of complexes showed significant activities against all the bacteria tested as compared to that of standard antibiotic ampicillin, however, the three mixed-ligand complexes including triphenylphosphane as ligand exhibited perceptibly stronger antibacterial activity than the three homoleptic ones possessing only the mbtt ligand. DNA electrophoretic mobility experiments showed that all complexes bind to CT-ds DNA resulting in high molecular weight complexes ending in DNA degradation.