Synthesis,Structures and Room Temperature Phosphorescence of 2-(2-Methoxynaphthyl)-1H-imidazo[4,5-f][1,10]-(1)phenanthroline-Cu(I) Complexes

A new ligand, 2-(2-methoxynaphthyl)-1H-imidazo[4,5-f][1,10]phenanthroline(mnipH), was synthesized by the condensation of 2-methoxy-1-naphthaldehyde and 5,6-diamino-1,10-phenanthroline. Then three ionic copper(I) complexes were obtained through the reactions of [Cu(MeCN)_4]ClO_4, mnipH and the chelating diphosphine ligands with a molar ratio of 1:1:1. The photoluminescence and the corresponding luminescent mechanism of all copper(I) complexes in the solid state were investigated at room temperature.     

Copper(I) complexes with 1-(2-carboxyphenyl)-5-heterylhydrazidinyl-6-celluloses as reversible redox indicators

A number of reagent test papers were designed on the basis of redox indicators: copper(I) complexes with sheet polydentate 1-(2-carboxyphenyl)-5-heterylhydrazidinyl-6-celluloses (I?CIV) (heteryl = 6-methoxy-4-methylpyrimidin-2-yl, 4,6-dimethylpyrimidin-2-yl, benzoxazol-2-yl, and benzothiazol-2-yl). Complexes I?CIV were transformed under the action of H₂O₂ into copper(II) complexes with 1-(2-carboxyphenyl)-5-heterylformazanyl-6-celluloses (V?CVIII), respectively. When treated with Na₂S, complexes V?CVIII were reversibly reduced to the starting copper(I) complexes I?CIV. The reactions were accompanied by bathochromic shifts from the central region of the visible spectrum to the higher wavelengths. Complex I was used to develop visual and reflectometric test methods for checking the peroxide content of pharmaceuticals and cosmetics at a level of 0.01% and above.     

Asymmetric dinuclear copper(I) complexes of bis-(2-(2-pyridyl)ethyl)-2-(N-toluenesulfonylamino)ethylamine with short copper-copper distances

Addition of two equivalents of CuCl to deprotonated bis-(2-(2-pyridyl)ethyl)-2-(N-toluenesulfonylamino)ethylamine (PETAEA) and its derivatives yielded new types of dinuclear Cu(I) complexes, Cu(mu-PETAEA)CuCl, Cu(mu-PEMAEA)CuCl, and Cu(mu-PENAEA)CuCl (PEMAEA is the 4-methoxyphenyl derivative of PETAEA and PENAEA is the 4-nitrophenyl derivative), exhibiting a four coordinate N(4)Cu center, a two coordinate NCuCl center, and a metal-metal distance within the range of 2.6572(8) to 2.6903(3) A. Analysis of the covalent radii for four coordinate and two coordinate copper(I), the acute copper-nitrogen-copper angles, and density functional theory (DFT) calculations suggest a weak attraction between the two copper atoms. The complexes apparently formed in a two-step process with the formation of the tetracoordinate mononuclear complex preceding the coordination of a second equivalent of CuCl to the lone pair of the sulfonamidate ligand.     

Synthesis and characterization of novel dinuclear copper(I) complexes. Dimerization of [CuL(PPh3)2] (L = methyl 3-hydroxy-3-(p-R-phenyl)-2-propenedithioate)

We report the synthesis of new copper(I) complexes 6a-e from methyl 3-hydroxy-3-(p-R-phenyl)-2-propenedithioate ligands. These complexes were characterized by IR and 1H, 13C, and 31P NMR spectroscopy. The expected O,S-coordination mode was confirmed by the X-ray diffraction studies of 6b and 6e. The unexpected dimerization of 6b-e leads to the formation of four novel dinuclear copper(I) compounds (7b-e). The dinuclear complex structure was fully established by the X-ray diffraction analysis of 7a, in which the presence of a Cu-Cu interaction was observed.     

Atmospheric pressure chemical ionization mass spectrometric and visible spectrophotometric studies of copper(I) and copper(II) complexes with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol.

Complexes of copper(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP) formed in aqueous methanol in a wide range of pH (from acidic to alkaline) as well as copper(I)-5-Br-PADAP species formed in methanolic solutions were investigated by spectrophotometry and mass spectrometry. Pseudomolecular and fragment ions created in the atmospheric pressure chemical ionization (APCI) source confirmed the molecular masses of the complexes existing in the solvents and their structures. The structure of the Cu(II) complex with 5-Br-PADAP formed in acidic medium was proposed as CuR(R - H) (where R is the undissociated molecule of the reagent). The binding sites of the two bound reagent molecules were different: in one of them the oxygen atom of the dissociated phenolic group and the nitrogen atom from the azo (-N=N-) group took part in complex formation, whereas in the other only nitrogen atoms from the pyridyl ring and azo group were involved. The complex was stable and could not be reduced to Cu(I) species by use of standard reducing agents (ascorbic acid, hydroxylamine). In alkaline solutions the complex tended to polymerize and precipitated in media containing less than 80% of methanol. The copper(I)-5-Br-PADAP complex was extremely unstable and could be obtained (as a mixture with Cu(II) species) in media free of water or oxygen. For this complex, CuR(2) was proposed as the most probable structure. According to this proposal copper(I) reacted exclusively with nitrogen-containing binding sites and the undissociated phenolic group was not engaged in complex formation. In this system Cu(I)/Cu(II) electron transfer is very rapid, accelerated by a polar environment, e.g. in the presence of water molecules or dissolved oxygen.     

Flow injection spectrophotometric determination of sub-mg dm(-3) silver(I) in a strongly acidic solution containing concentrated copper(II) using a pyridylazo reagent

A novel spectrophotometric flow injection method for determination of silver(I) in a strongly acidic solution containing concentrated copper(II) was developed using a coloring ligand, 4-(3,5-dibromo-2-pyridylazo)-N-ethyl-N-(3-sulfopropyl)aniline (3,5-diBr-PAESA). The method was first investigated by batch method. The interference from copper(II) chelate could be eliminated by the masking effect of EDTA. By utilizing the large formation constant (K = 12.3) of AgBr, one could determine silver(I) as a decrease of absorption by silver(I) chelate due to formation of AgBr by addition of KBr. Based on the results of batch experiments, two types of flow injection analysis (FIA) systems were constructed. Sub-mg dm(-3) determination of silver(I) was attained without interference from excess copper(II). The proposed method was successfully applied to determination of silver in a copper plating solution used in a plant to manufacture copper printed circuit boards, where the concentration of silver was critically important in the process control.     

Enantioselective synthesis of (-)-roccellaric acid

[reaction in text] A new strategy for the synthesis of anti-4,5-disubstituted gamma-butyrolactones starting from inexpensive furan-2-carboxylic methyl ester was developed. By applying this methodology, the enantioselective synthesis of (-)-roccellaric acid ((-)-17) was accomplished using a copper(I)-catalyzed asymmetric cyclopropanation, a tin(IV)-catalyzed retroaldol/lactonization sequence of cyclopropanols, and a ruthenium-catalyzed intermolecular metathesis reaction as key steps.     

Synthesis of 2-(polyfluoroaryl)benzofurans via a copper(I)-catalyzed reaction of 2-(2,2-dibromovinyl)phenol with polyfluoroarene

A novel and efficient route for the synthesis of 2-(polyfluoroaryl)benzofurans via a copper(I)-catalyzed tandem reaction of 2-(2,2-dibromovinyl)phenol with polyfluoroarene is reported. The corresponding products are generated in good yields. During the reaction process, a copper-catalyzed intramolecular C-O bond formation and a C-H activation are involved.     

Synthese und Struktur des Kupferkomplexes 2-(2-Hydroxy-5-methylphenyl)-6-(2-hydroxyphenyl)pyridinato(2−)-dipyridin-kupfer(II) und des freien Liganden

Synthesis and Structure of the Copper Complex 2-(2-Hydroxy-5-methylphenyl)-6-(2-hydroxyphenyl)pyridinato(2?)dipyridin-copper(II) and of the free Ligand The tridentate diacidic ligand 2-(2-hydroxy-5-methyl)-6-phenyl-6-(2-hydroxyphenyl)pyridine 4a was synthesized and characterized by X-ray structural analysis. The compound forms a copper complex, 2-(2-Hydroxy-5-methyl-phenyl)-6-(2-hydroxyphenyl)pyridinato(2?)-dipyridine copper(II), which was crystallized from pyridine solution. The coordination number of the central atom copper ist five.     

Synthesis, characterization, and tautomerism of four novel copper(I) complexes from 3-hydroxy-3-(p-R-phenyl)-2-propenedithioic acids

The paper describes the synthesis and structural characterization of four novel copper(I) complexes [CuL(PPh(3))(2)] (L = 3-hydroxy-3-(p-R-phenyl)-2-propenedithioate). In addition, a tautomeric equilibrium in solution was found and Hammett correlations with (13)C NMR parameters were studied. The structure of one complex was fully established by X-ray diffraction analysis.     

Synthesis of 2(3H)-benzofuranone derivatives by copper (i)-promoted substitution reactions of active methylene carbanions

Activation of soft carbanions by copper(I) in the sub-stitution reaction toward aryl halides and allyl halides was demonstrated. Derivatives of 2(3H)-benzofuranones (2, 14 -18) were prepared in a one-pot procedure by the reaction of copper(I) diethyl malonate with sodium o-bromophenoxide. 2-Hydroxybenzofuran (4) and its 2-amino derivative (5) were obtained by using copper(I) salts of ethyl acetoacetate and ethyl cyanoacetate. The reaction of sodium p-bromophenoxides with copper(I) diethyl malonate yielded p-1,1,2,2-tetracaeboethoxyethylphenols (7, 8). 3-Carboethoxy-3-β-methallyl-2-benzofuranone (14) was converted into spiro[2-benzofuranone-3,3'-(5',5'-dimethyl)-γ-butyrolactone] (22) under acidic conditions. The latter compound was further decarboxylated to give spiro [2-benzofuranone-3,1'-(2',2'-dimethyl)cyclopropane] (23) by the treatment with sodium ethoxide.     

Synthesis,characterization, and polymerization activity of [bis(4,4'-bis(neophyldimethylsilylmethyl)-2,2'-bipyridyl)copper(I)]+CuBr2- and Implications for copper(I) catalyst structures in atom transfer radical polymerization

A series of 4,4'-disilyl-substituted-2,2'-bipyridine ligands were prepared using a metathesis reaction of the dianion of 4,4'-dimethyl-2,2'-bipyridine with several trialkylsilyl chlorides: 4,4'bis(tert-butyldimethylsilylmethyl)-2,2'-bipyridine (dTBDMSbipy), 4,4'-bis(dimethylthexylsilylmethyl)-2,2'-bipyridine (dTHEXbipy), and 4,4'-bis(neophyldimethylsilylmethyl)-2-2'-bipyridine (dNEObipy). It was observed that the side chain length correlated with the ability of the ligand to form hydrocarbon soluble complexes of copper(I) bromide, with dNEObipy forming the most soluble and easily crystallized complexes. The atom transfer radical polymerization (ATRP) of styrene using dNEObipy as the ligand displayed molecular weight control equivalent to other ATRP systems in which solubilizing ligands, such as 4,4'-di-5-nonyl-2,2'-bipyridine or 4,4'-di-n-heptyl-2,2'-bipyridine, were used. The one-to-one complex of dNEObipy with CuBr was prepared and its crystal structure was determined. The resulting complex had the ionic formulation [(dNEObipy)2Cu]+[CuBr2]- and displayed similar activities in styrene ATRP as the standard 2 dNEObipy/CuBr catalyst system. These and other polymerization results in addition to NMR experiments suggest that the predominant copper(I) species formed in ATRP solutions is the 2-to-1 ligand-to-copper(I) cation, [(dNEObipy)2Cu]+, with either a dihalocuprate or halide counteranion, depending upon the conditions.     

A molecular pinwheel multicopper(I) cluster, [(L(S-))6Cu(I)13(S2-)2]3+ with mu4-sulfido, mu3-thiolato and nitrogen ligands

A copper(I) complex with new N2S thiol ligand transforms to a multicopper(I) cluster, [(L(S-))6Cu(I)13(S2-)2]3+ (1); its X-ray structure exhibiting mu4-sulfido and mu3-thiolato coordination is presented and compared to other cuprous thiolato/sulfido clusters including that observed in the copper enzyme nitrous oxide reductase.     

Regioselective synthesis of 1-(2,2-dimethoxyethyl)-1,2,3-triazoles by copper(I)-catalyzed [3+2] cyclization of 2-azido-1,1-dimethoxyethane with alkynes

1-(2,2-Dimethoxyethyl)-1,2,3-triazoles are regioselectively prepared by copper(I)-catalyzed [3+2] cyclizations of 2-azido-1,1-dimethoxyethane with alkynes.     

Facile synthesis of 2-(phenylthio)phenols by copper(I)-catalyzed tandem transformation of C-S coupling/C-H functionalization

2-(Phenylthio)phenols were successfully synthesized from simple phenols and aromatic halides by using dimethyl sulfoxide as the oxidant. The transformation was accomplished via tandem copper(I)-catalyzed C-S coupling/C-H functionalization employing the CuI/L [L = (E)-3-(dimethylamino)-1-(2-hydroxyphenyl)prop-2-en-1-one] catalyst system. The mechanism of the reaction was elucidated based on an isotope labeling strategy.     

Studies on the Dual-wavelength Spectrophotometric Determination of Trace Copper with 5-(5-nitro-2-pyridylazo)-2,4-diamino-toluene

A new dual-wavelength spectrophotometry has been developed for the determination of copper(I) with 5-(nitro-2-pyridylazo)-2,4-diamino-toluene.     

Structures and luminescence properties of two copper(I) halide complexes featuring 2-(2-benzimidazolyl)-6-methylpyridine

Two new copper（I） halide complexes bearing 2-（2-benzimidazolyl）-6-methylpyridine（Hbmp） and PPh₃ ligands, Cu（Hbmp）（PPh₃）X（X = Br（1）;I（2））,have been synthesized and characterized.Single-crystal X-ray structure analysis reveals that the halide ligand has a significant impact on the Cu-N_pyridyl bond lengths.Complexes 1 and 2 show the solid-state emissions at ambient temperature,varying with the halide bound to the {Cu（Hbmp）（PPh₃）} motif,which are perhaps best attributed to the metal-to-ligand charge-transfer（Cu（I）→Hbmp） transition mixed with some ligand-to-ligand charge-transfer（X and PPh₃→Hbmp） character.     

Phosphorescent Cu(I) complexes of 2-(2'-pyridylbenzimidazolyl)benzene: impact of phosphine ancillary ligands on electronic and photophysical properties of the Cu(I) complexes

Four mononuclear Cu(I) complexes of 2-(2'-pyridyl)benzimidazolylbenzene (pbb) with four different ancillary phosphine ligands PPh(3), bis[2-(diphenylphosphino)phenyl]ether (DPEphos), bis(diphenylphosphino)ethane (dppe), and bis(diphenylphosphinomethyl)diphenylborate (DPPMB) have been synthesized. The crystal structures of [Cu(pbb)(PPh(3))(2)][BF(4)] (1), [Cu(pbb)(dppe)][BF(4)] (2), [Cu(pbb)(DPEphos)][BF(4)] (3), and the neutral complex [Cu(pbb)(DPPMB)] (4) were determined by single-crystal X-ray diffraction analyses. The impact of the phosphine ligands on the structures of the copper(I) complexes was examined, revealing that the most significant impact of the phosphine ligands is on the P-Cu-P bond angle. The electronic and photophysical properties of the new complexes were examined by using UV-vis, fluorescence, and phosphorescence spectroscopies and electrochemical analysis. All four complexes display a weak MLCT absorption band that varies considerably with the phosphine ligand. At ambient temperature, no emission was observed for any of the complexes in solution. However, when doped into PMMA polymer (20 wt %), at ambient temperature, all four complexes emit light with a color ranging from green to red-orange, depending on the phosphine ligand. The emission of the new copper complexes has an exceptionally long decay lifetime (>200 micros). Ab initio MO calculations established that the lowest electronic transition in the copper(I) complexes is MLCT in nature. The electronic and photophysical properties of the new mononuclear Cu(I) complexes were compared with those of the corresponding polynuclear Cu(I) complexes based on the 2-(2'-dipyridyl)benzimidazolyl derivative ligands and the previously extensively studied phenanthroline-based Cu(I) complexes.     

Synthesis and Crystal Structure of a One-dimensional Ladder-like Complex [Cu2(L)(dca)2]n (dca = [N(CN)2]-,L = 1,4-Bis(3-furanyl)-2,3-diaza-1,3-butadiene)

A new Cu(I)-dicyanamide with formula [Cu2(L)(dca)2]n (dca = dicyanamide anion, L = 1,4-bis(3-furanyl)-2,3-diaza-1,3-butadiene) has been synthesized and structurally characterized.The complex crystallizes in the monoclinic system, space group P21/n with a = 9.271(2), b = 7.7355(16), c = 11.967(3) -, β = 102.693(3)°, V = 837.3(3) -3, Z = 4, Mr = 223.68, Dc = 1.775 g/cm3, μ(MoKα) = 2.567 mm-1, F(000) = 444, R = 0.0782 and wR = 0.2582 for 951 observed reflections (I > 2σ(I)).Single-crystal X-ray analysis reveals that the copper atom is three-coordinated by two nitrogen atoms from two dicyanamide anions and another one from the ligand, and each copper atom is connected by two [N(CN)2]- anions to form an infinite double-stranded bridge fashion leading to 1D ladder-like motifs.     

Extraction behaviour of copper(II) and silver(I) with a thiacrown ether carboxylic acid, 2-(3,6,10,13-tetrathiacyclotetradec-1-oxy)hexanoic acid

The extraction behaviour of copper(II) and silver(I) with 2-(3,6,10,13-tetrathiacyclotetradec-1-oxy)hexanoic acid (TTCTOHA) was investigated at 25+/-0.1 degrees C and ionic strength of 0.1. The value of the logarithmic distribution coefficient, logK(DR) of TTCTOHA between octan-1-ol and aqueous phases was determined to be 4.13. Copper(II) was extracted with TTCTOHA into octan-1-ol as CuL(2), where L represents the anionic species of TTCTOHA. The logarithmic extraction constant, logK(ex(10)), was determined at -7.42. Silver(I) was extracted with TTCTOHA into octan-1-ol as AgL and Ag(2)L(2). The logarithmic distribution constant, logK(DC), of AgL was estimated to be 0.49. On the other hand, silver(I) was extracted into 1,2-dichloroethane as AgL and the logarithmic extraction constant, logK(ex(10)), was determined to be -2.24.