15061-57-1Relevant academic research and scientific papers
Structural studies on tris(2-cyanoethyl)phosphine complexes of Cu(I): The sensitivity of the secondary nitrile coordination to the nature of the anion
Davidson, Ross J.,Ainscough, Eric W.,Brodie, Andrew M.,Freeman, Graham H.,Jameson, Geoffrey B.
, p. 330 - 337 (2014)
Tris(2-cyanoethyl)phosphine (tcep) reacts with the copper(I) compounds, CuX (X = Cl, Br, I and SCN), in a 1:1 ratio to give 1:1 complexes, CuX(tcep), whereas it reacts with CuY (Y = PF6, ClO4, NO3, BH4, CN and CF3COO) in a 2:1 ratio to give the 2:1 complexes, CuY(tcep)2. Single crystal X-ray structures show that for the anions X = Br and SCN, the complexes are coordination polymers, [CuX(tcep)]n, with the Cu centres being bridged by the anion, and as well, one nitrile arm per tcep ligand coordinates intermolecularly to the Cu to give tetrahedral 'PBr2N' and 'PSN2' coordination spheres respectively. The 2:1 compounds exhibit a variety of structures. For Y = ClO4, CN and CF3COO polymeric structures are formed except for Y = BH4 where the compound is a discrete monomer, [Cu(BH 4)(tcep)2], with a chelating anion and two monodentate P-bound tcep ligands. Both the compounds obtained with Y = CN and CF 3COO also contain coordinated anions and are formulated as [Cu(CN)(tcep)2]n and [Cu(CF3COO)(tcep) 2]n respectively. In the case of Y = CN the anion is bridging and the tcep ligands are only P-bound giving a 'P2NC' coordination sphere. In contrast, for Y = CF3COO, the anion is an O-bound monodentate and the tcep ligands bridge to give a 'P2NO' environment for the copper. In the case of Y = ClO4, the anion is not coordinated but a polymeric structure, [Cu(tcep)2] n(ClO4)n, is formed via bridging tcep ligands linking Cu centres intermolecularly resulting in a 'P2N2' coordination sphere.
Cuprous halide complexes of a variable length ligand: Helices, cluster chains, and nets containing large solvated channels
Gee, William J.,Batten, Stuart R.
, p. 2335 - 2343 (2013)
The variable-length azacrown ether bridging ligand N,N′-bis(3- pyridyl-methyl)diaza-18-crown-6 (b3pmdc) was reacted with cuprous iodide to give a range of new discrete and polymeric coordination compounds. Six structurally diverse CuI(b3pmdc) architectures were isolated, as well as a single oxidized CuII(b3pmdc) species. These include the helical one-dimensional (1D) chain [H4b3pmdc][Cu10I 14]·CHCl3·2H2O (1), the luminescent linear cluster chain [Cu4I6(H 2b3pmdc)] (2), the guest water containing network [Cu 4I4(Hb3pmdc)2](1.5ClO4)(0.5I 3)·3.5H2O·2.5MeOH (3), the luminescent cubane cluster chain [Cu4I4(b3pmdc)2] (4), the three-dimensional (3D) net [Cu9I12(Kb3pmdc) 3(H2O)4]·9MeOH (5), the dinuclear mixed halide [Cu2Cl3.4I2.6(H4b3pmdc)] (6), and the cupric 1D chain [CuCl2(H2b3pmdc)(MeOH) 2]·2Cl·2MeCN (7). Manipulation of the ligand conformation was achieved by the addition of the alkali metal salt potassium and by varying the pH of the solution with a range of acids (HCl, HClO 4). In the case of 2 and 4, green and yellow luminescent emission was observed, as a result of the varied metal environment.
Catalytic Aerobic Phenol Homo- and Cross-Coupling Reactions with Copper Complexes Bearing Redox-Active Guanidine Ligands
Sch?n, Florian,Kaifer, Elisabeth,Himmel, Hans-J?rg
supporting information, p. 8279 - 8288 (2019/06/04)
Due to their large importance in synthetic chemistry, catalytic C?C coupling reactions of phenols are currently intensively studied. Herein, new copper catalysts for the C?C coupling reaction of phenols using dioxygen as a green oxidizing reagent are reported. By using redox-active guanidine ligands, the activity as well as chemoselectivity in the cross-coupling reaction of non-complementary phenols (between an electron-rich phenol and a less nucleophilic second phenol) is significantly improved. Based on the collected data for several test reactions, a reaction mechanism is proposed.
Preparations and properties of transition-metal pterin complexes. Models for the metal site in phenylalanine hydroxylase
Perkinson, Joanna,Brodie, Sharon,Yoon, Keum,Mosny, Karoline,Carroll, Patrick J.,Vance Morgan,Nieter Burgmayer, Sharon J.
, p. 719 - 727 (2008/10/08)
Syntheses and physical properties of pterin and pteridine complexes of first-row transition metals are described. Characterization used single-crystal x-ray diffraction, spectroscopic, and microanalytical methods. These data all indicate that pterin and pteridine ligands chelate via oxygen and nitrogen atoms. Three copper complexes have been structurally determined. Cu(tppb)(pterin) (1) [tppb- = tris(3-phenylpyrazolyl)hydroborate] crystallizes in the triclinic space group P1 with cell dimensions a = 11.835 (2) ?, b = 12.062 (2) ?, c = 12.831 (2) ?, α = 66.91 (1)°, β = 83.68 (1)°, and γ = 77.10 (1)° defining a volume of 1641.9 ?3 for Z = 2. The five-coordinate cupric ion has a square-pyramidal geometry, and the pterin ligand occupies two equatorial positions. Pterin coordination in 1 significantly differs from the only extant report of a cupric pterin complex both in orientation and in Cu-O bond strength. Cu(ethp)2(phen) (4) [ethp = 2-(ethylthio)-4-oxopteridine; phen = 1,10-phenanthroline] also crystallizes in the triclinic space group P1. Unit cell parameters a = 12.414 (2) ?, b = 12.882 (2) ?, c = 11.371 (2) ?, α = 112.55 (2)°, β = 92.58 (1)°, and γ = 83.96 (1)° define a volume of 1670.1 ?3 for Z = 2. The copper coordination sphere has an elongated octahedral geometry defined by four equatorial nitrogen atoms (two from the pteridines and two from phenanthroline) with axial positions filled by oxygen atoms of the pteridine chelates. The third structure reported is for the compound [Cu(phen)2(acetate)] [acetate- H-ethp] (5). In this structure, the pteridine does not chelate copper but is incorporated into the anionic counterion. The compound crystallizes in the monoclinic cell P21/c with parameters a = 11.755 (2) ?, b = 19.079 (2) ?, c = 16.329 (2) ?, and β = 110.36 (1)°, resulting in a cell volume of 3343.6 ?3 for Z = 4. The copper atom is coordinated in a distorted square-pyramidal geometry composed of two phenanthroline chelates and one monodentate acetate ligand. The anion can be formulated as an acetate hydrogen-bonded to the hydroxyl group of the pteridine enol tautomer. A comparison of EPR parameters for the copper complexes reported in this manuscript with previous data for copper pterin complexes reveals that only the value of A∥ is sensitive to variation in copper environments. Spectroscopic and structural data point to a stronger metal-pterin interaction for equatorially bound pterinate ligands. Preliminary results of copper(II) reduction by tetrahydropterin are also presented.
Synthesis and Characterization of Coordination Compounds of Chelating Ligands Containing Imidazole Groups. The Crystal and Molecular Structures of the Dinuclear CuI and CuII Compounds dicopper(I)Bis(perchlorate) and ...
Hendriks, Hugo M. J.,Birker, Paul J. M. L.,Rijn, Jacobus van,Verschoor, Gerrit C.,Reedijk, Jan
, p. 3607 - 3617 (2007/10/02)
Copper(I) and copper(II) coordination compounds with general formulas CuII(L)(anion)2, CuII2(L)(anion)4, and CuI(L)(anion)2 have been prepared and characterized, where L stands for one of the sexadentate benzimidazole-containing ligands N,N,N',N'-tetrakis(2-benzimidazolylmethyl)-1,2-ethanediamine (abbreviated EDTB), N,N,N',N'-tetrakis-1,2-ethanediamine (NMEDTB), N,N,N',N'-tetrakis-1,1-ethanediamine (NBEDTB), N,N,N',N'-tetrakis-1,2-ethanediamine (5-MEDTB),or N,N,N',N'- tetrakis-1,2-ethanediamine (5,6-DMEDTB).The electronic and ECR spectra of all compounds of the composition CuII(L)(anion)2 are identical with those for Cu(EDTB)(anion)2 and suggest a structure similar to the one found for Cu(EDTB)(BF4)(BF3OC2H5), which has been described as highly distored square pyramid.ECR and electronic spectra of the compounds Cu2(L)(anion)2 indicate different coordination geometries in the presence of different anions.In compounds with Cl- or Br- the CuII atom appears to have trigonal-bipyramidal coordination geometry.Square-pyramidal geometry seems more likely for compounds Cu2(L)X4, where X=NO3-, BF4-, or ClO4-.The crystal and molecular structures of II2(NMEDTB)(NO3)3>NO3*4H2O (1) and of CuI2(EDTB)(ClO4)2 (2) have been determined by single-crystal X-ray analysis.Both compounds crystallize in space group C2/c.For compound 1, a=19.159 (4) Angstroem b=15.907(2) Angstroem, c=16.816(3) Angstroem, β=109.57(2)deg, V=4829.0 Angstroem 3, Z=4, dmeasd=1.51(1) g cm-3, and dcalcd=1.49 g cm-3.The intensities of 4241 independent reflections were measured on an automatic diffractometer, 2670 of which were considered as observed (I>2?(I)).For compound 2, a=13.849 (2) Angstrom, b=18.913(2) Angstroem, c=14.062(2) Angstroem, β=102.10(1) deg, V=3592.2 Angstroem 3, Z=4, dmeasd=1.65(1) g cm-3, and dcalcd=1.68 g cm-3.A total of 3522 independent reflections were measured, 2627 of which were considered as observed.Both structures were solved by heavy-atom methods and refined by using least-squares techniques to a residual R value of 0.046 for 1 and 0.039 for 2.Structure 1 consists dinuclear Cu2(NMEDTB)(NO3)3+ cations having C2 symmetry, a disordered nitrate ion, and disordered water molecules.The coordination geometry around each copper ion can be described as square pyramidal with two equatorial benzimidazole nitrogen atoms, one equatorial amine nitrogen atom, one equatorial oxygen atom of monodentante coordinating nitrate ion, and one axial oxygen atom of a nitrate ion which is bridging to the axial position of the copper ion in the cation.Structure 2 consists of dinuclear CuI2(EDTB)2+ cations having C2 symmetry and perchlorate ions.Each copper is linearly coordinated by two benzimidazole nitrogen atoms, with short Cu-N bonds of 1.869(4) and 1.876(4) Angstroem, respectively.The Cu-Cu ...
