Paddle-wheel Copper Research Articles

Correction to Highly Organized Structures and Unusual Magnetic Properties of Paddlewheel Copper(II) Carboxylate Dimers Containing the π–π Stacking, 1,8-Naphthalimide Synthon

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionCorrection to Highly Organized Structures and Unusual Magnetic Properties of Paddlewheel Copper(II) Carboxylate Dimers Containing the π–π Stacking, 1,8-Naphthalimide SynthonDaniel L. Reger*, Agota Debreczeni, Bryn Reinecke, Vitaly Rassolov, Mark D. Smith, and Radu F. SemeniucCite this: Inorg. Chem. 2011, 50, 10, 4669–4670Publication Date (Web):April 19, 2011Publication History Published online19 April 2011Published inissue 16 May 2011https://doi.org/10.1021/ic200654nCopyright © 2011 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views633Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (725 KB) Get e-Alerts Get e-Alerts

Crystal structures and magnetism of infinite alternating chains arranged by paddle-wheel dinuclear copper and mononuclear copper units

The crystal structures and magnetic properties of two novel polyclusters {[Cu(3)(tci)(2)(H(2)O)(2)]·12H(2)O}(n) (1) and {[Cu(3)(tci)(2)(H(2)O)(2)]·6H(2)O}(n) (2) (tci = tris(2-carboxyethyl) isocyanurate) are investigated. The X-ray crystallographic analysis reveals that they contain interesting infinite alternating chains of dinuclear paddle-wheel copper and mononuclear copper units arranged in ABBA magnetism exchange mode. Variable-temperature magnetic susceptibility measurements on the two polyclusters show strong antiferromagnetism couplings between copper ions with exchange interactions J = -181.4 cm(-1), zj' = -0.31 cm(-1) for 1, J = -170 cm(-1), zj' = -0.42 cm(-1) for 2. With the aim of studying magneto-structural correlation, we synthesized a three-dimensional polymer [Cu(3)(tci)(2)(py)(4)(H(2)O)(2)](n) (3) based on isolated dinuclear cluster and mononuclear copper units. Fitting the susceptibility data yielded J = -176.1 cm(-1), zj' = -0.084 cm(-1) for 3.

Highly Organized Structures and Unusual Magnetic Properties of Paddlewheel Copper(II) Carboxylate Dimers Containing the π−π Stacking, 1,8-Naphthalimide Synthon

The substituted carboxylate compounds N-(3-propanoic acid)-1,8-naphthalimide (HL(C2)) and N-(4-butanoic acid)-1,8-naphthalimide (HL(C3)) react with Cu(2)(O(2)CCH(3))(4)(H(2)O)(2) in the presence of either pyridine (py) or 4,4'-bipyridine (bipy) to produce the dimeric complexes [Cu(2)(L(C2))(4)(py)(2)].2(CH(2)Cl(2)).(CH(3)OH) (1), [Cu(2)(L(C3))(4)(py)(2)].2(CH(2)Cl(2)) (2), [Cu(2)(L(C2))(4)(bipy)].unknown solvent (3), and [Cu(2)(L(C3))(4)(bipy)].(CH(3)OH)(2).(CH(2)Cl(2))(3.37) (4). The core of these four compounds contains the square Cu(2)(O(2)CR)(4) "paddlewheel" secondary building unit (SBU) structural motif with nonbonding Cu...Cu distances that average 2.66 A, with each copper in a nearly square pyramidal geometry. Strong pi-pi stacking interactions of the 1,8-naphthalimide groups organize the structures of 1 and 2 into sheets and into a three-dimensional structure for 1. The propylene connector in the L(C3) ligand allows an arrangement of the 1,8-naphthalimide groups that is different from the square shape of the SBU core. Use of the 4,4'-bipyridine linking ligand produces a three-dimensional structure for 4 organized by both covalent bonds and noncovalent forces where the 1,8-naphthalimide groups organize into a sheet structure and the 4,4'-bipyridine ligands link the sheets. In contrast, in 3, the 1,8-naphthalimide groups overlap to form only one-dimensional ribbons, with the second dimension formed by the 4,4'-bipyridine ligands and the third dimension linked by mechanical interlocking of these two-dimensional units. Although many of the pi-pi stacking interactions of the 1,8-naphthalimide groups are made with the dipole vectors of this group oriented at 180 degrees (head-to-tail arrangement), skewed arrangements are observed in many cases. Ab initio calculations show that the interaction is relatively insensitive to this angle of rotation, apart from the region of steric repulsion when the rotation angle of the dipoles approaches 0 degrees. Structural results also demonstrate that the rings can slip with respect to each other and maintain substantial interactions. Magnetic measurements show that the compounds are strongly antiferromagnetically coupled with J values ranging from -270 to -341 cm⁻¹, values typical for these types of dimers. [corrected]

Magnetic coupling detected by EPR in a paddle-wheel copper(II) complex of the amino acid guanidinoacetic acid

Interesting magnetic properties of a paddle-wheel carboxylate bridged copper(II) complex of guanidinoacetic acid (GAA), Cu2(GAA)4(NO3)2 (tetrakis(μ-guanidinoacetic acid-κ2O:O′) bis[(nitrato-κO) copper(II)]) (I) were detected by electron paramagnetic resonance (EPR). The complex I contains two copper ions coordinated to four GAA ligands (d Cu–Cu 2.65Å) through the oxygen atoms from the carboxylate group forming a paddle-wheel complex and a supramolecular assembly. The EPR data (40–300K) revealed two distinct groups of lines. One of them is related to the intra-dimer coupling, an anti-ferromagnetic interaction between the copper ions. The other group of lines, which was only observed above 180K, can be attributed to the inter-dimer coupling or pair formation.

Polynuclear paddle-wheel copper(II) propionate with di-2-pyridylamine or 1,10-phenanthroline: Preparation, characterization and X-ray structure

The synthesis, spectroscopic, magnetic and structural characterization of two new polynuclear copper(II) propionate are described. Both compounds exhibit the typical paddle-wheel type structure. The complex [Cu 4(dpyam) 2(OCOC 2H 5) 2(μ-O 2CC 2H 5) 6(H 2O) 2][Cu 2(μ- O 2CC 2H 5) 4(H 2O) 2] · (DMF) 2 1; where dpyam = di-2-pyridylamine, the “outer” Cu ions, with a CuN 2O 2O′ chromophore, have an intermediate five-coordinate geometry. The “inner” Cu ions, with a CuO 4O′ chromophore, have a square pyramidal geometry. The two Cu(II) ions in the inner unit are bridged by four syn, syn-η 1:η 1:μ propionates, showing the paddle-wheel cage type. The “outer” and “inner” linked by propionate bridges showing syn, anti-η 1:η 1:μ coordination mode. The 1D structure of complex [Cu 6(phen) 2(H 2O) 2(μ-O 2CC 2H 5) 12] n [Cu 2(μ-O 2CC 2H 5) 4(H 2O) 2] 2 n · (H 2O) 0.5 n 2; where phen = 1,10-phenanthroline, consists of zig-zag chains of mononuclear Cu(μ-O 2CC 2H 5) 2(H 2O)(phen) repeating units running along the b-axis, which are connected along the unit cell diagonal via Cu 2(μ-O 2CC 2H 5) 4 paddle-wheel dinuclear units. Within mononuclear and dinuclear units, the Cu(II) ions have a square pyramidal geometry. However, the outer sphere of both compounds consists of the Cu 2(μ-O 2CC 2H 5) 4(H 2O) 2 paddle-wheel molecule in which Cu(II) ions involve a square pyramidal geometry.

The self-assembly between C2-symmetric (methanol)6 or S6-symmetric (ethanol)6 cyclohexamers and paddle-wheel dinuclear copper units leads to unique 1D polymer chains

The first crystallographic evidences of the theoretically suggested C2-symmetric cyclohexameric form of liquid methanol and the S6-symmetric cyclohexameric form of liquid ethanol are reported, trapped inside a hydrophilic pocket shielded by tert-butyl groups.

Metal complexes with pyridone-based radicals: Preparation and properties of a dinuclear paddle-wheel copper(II) complex and a mononuclear palladium(II) complex

Abstract We prepared and characterized dinuclear copper(II) and mononuclear palladium(II) complexes coordinated with a pyridine-based open-shell ligand, 5-(4′,4′,5′,5′-tetramethylimidazoline-3′-oxide-1′-oxyl)-2(1H)-pyridone (=HL). In the copper(II) dinuclear complex [Cu2(L)4(DMF)2] (1), four deprotonated ligands are coordinated as bridging ligands to form a paddle-wheel type unit. In the palladium(II) complex trans-[PdCl2(HL)2] (2), two HL ligands in the neutral hydroxypyridine form are coordinated to the trans positions of the metal ion via the nitrogen atoms. The hydroxyl groups of the ligands are hydrogen-bonded to the chlorine atoms of neighboring molecules, thereby creating a hydrogen-bonded double-chain molecular arrangement. Magnetic susceptibilities of these complexes were measured and analyzed. The small intramolecular antiferromagnetic interaction in the latter complex may originate from superexchange through the diamagnetic metal center.

Synthesis, crystal structure, and spectroscopic characterization of trans-bis[(mu-1,3-bis(4-pyridyl)propane)(mu-(3-thiopheneacetate-O))(3-thiopheneacetate-O)]dicopper(II), [[Cu2(O2CCH2C4H3S)4mu-(BPP)2]]n: from a dinuclear paddle-wheel copper(II) unit to a 2-D coordination polymer involving monatomic carboxylate bridges.

From the reaction between a dinuclear paddle-wheel carboxylate, namely [Cu2mu-(O2CCH2C4H3S)4] (1), and the flexible ligand 1,3-bis(4-pyridyl)propane (BPP) a neutral 2-D coordination polymer [[Cu2(O2CCH2C4H3S)4mu-(BPP)2]]n (2) was obtained. Compounds 1 and 2 were characterized by means of elemental analysis, thermal analysis (TG/DSC), vibrational spectroscopy, and electron paramagnetic resonance (EPR). The crystal structure of 2 reveals that each Cu(II) is coordinated by two nitrogen atoms from different BPP ligands and two 3-thiopheneacetate groups within a distorted square planar geometry in a trans-[N, N, O, O] arrangement. The BPP ligand adopts a TG conformation bridging two copper centers giving rise to a 1-D sinusoidal polymeric chain along the crystallographic c axis. Adjacent 1-D chains are extended into a 2-D coordination network through pairs of monatomic carboxylate bridges in direction of the b axis. This bridging mode affords centrosymmetric dimeric units Cu2O2, and therefore, the copper ions are involved in a CuN2O2O' chromophore displaying a (4 + 1) square pyramidal coordination in the resultant 2-D polymeric network. The polycrystalline X-band EPR spectrum of 2 at room temperature is characteristic of a triplet state with nonnegligible zero-field splitting in agreement with the crystal structure. Crystal data for 2: monoclinic, space group P2(1)/c, a = 9.4253(10) A, b = 10.9373(10) A, c = 23.6378(10) A, beta = 98.733(4) degrees, Z = 2.

Synthesis, structural and magnetic properties of a series of copper(II) complexes containing a monocarboxylated perchlorotriphenylmethyl radical as a coordinating open-shell ligand.

A series of complexes of copper(II)-containing a perchlorotriphenylmethyl radical functionalized with a carboxylic group as a new ligand is reported. The compounds [Cu(PTMMC)(2)(L)(3)](PTMMC = (tetradecachloro-4-carboxytriphenyl)methyl radical; L =(1) H(2)O, (2) pyrimidine and ethanol or (3) pyridine), [Cu(2)(PTMMC)(2)(MeCOO)(2)(H(2)O)(2)](4) and [Cu(HPTMMC)(2)(L)(3)](HPTMMC =alpha-H-(tetradecachlorotriphenyl)methane-4-carboxylic acid; L = pyridine)(5) were structurally characterized. In complexes 1, 2, 3, and 5, the copper(II) ion is coordinated to two PTMMC (or HPTMMC) units in a slightly distorted square planar surrounding, while 4 shows a paddle-wheel copper(II) dimer structure, where each Cu metal ion has four O atoms of different carboxylate groups, two of them belonging to two PTMMC radicals. The copper(II)-radical exchange couplings are antiferromagnetic for complexes 1, 2 and 3. A linear three-spin model was applied to complexes 1, 2 and 3 to give J/k(B)=-24.9, -15.0 and -20.7 K, respectively. Magnetic properties of 4 show that it is one of the scarce examples of a spin-frustrated system composed of organic radicals and metal ions. In this case, experimental data were fitted to a magnetic model based on a symmetrical butterfly arrangement to give a copper(II)-copper(II) exchange coupling of J/k(B)=-350.0 K and a copper(II)-radical exchange coupling of J/k(B)=-21.3 K, similar to that observed for the copper(II)-radical interactions in complexes, and.

Structural diversity and properties of a series of dinuclear and mononuclear copper(ii) and copper(i) carboxylato complexes

The syntheses, crystal structures, magnetic and photoluminescence properties of a series of dinuclear and mononuclear copper(II) and copper(I) N-carbazolylacetate [N-carbazolylacetic acid = Hcabo] with different carboxylato coordination modes are reported. Although the carboxylato group has different coordination modes, the same carboxylate ligand binding to copper ion via four coordinating modes is rare. The crystal structure of complex [Cu2(Cabo)4(dmf)2]·2dmf (1) consists of a symmetrical dimeric Cu(II) carboxylato paddle-wheel core and oxygen atoms from dmf at the apical positions. The dinuclear complex [Cu2(Cabo)3(phen)2]ClO4·H2O·C2H5OH (2) (phen = 1,10-phenanthroline) consists of an unusual dimeric core with two copper atoms bridged by three carboxylates one of which is in the η∶η∶μ2 bridging mode and the other two are in the rarer monoatomic bridging mode. To our knowledge, the present bridging mode has not been reported hitherto. Magnetic susceptibilities were measured in the temperature range 2–300 K. It is found that paddle-wheel copper(II) ions in 1 are strongly coupled antiferromagnetically with 2J = −356.4(6) cm−1, whereas complex 2 shows weak antiferromagnetic interaction with a 2J value of −12.8(4) cm−1. Copper(I) N-carbazolylacetate with strong fluorescence in the solid state as well as high thermal stability was obtained by reduction of the copper(II) N-carbazolylacetate using PPh3 (triphenylphosphine) in dmf solution.

Magneto–structural correlation of dimeric copper(II) carboxylates with pyridyl-substituted nitronyl nitroxides

The synthesis, crystal structure and magneto–structural correlations of three new paddle-wheel type dicopper(II) carboxylate complexes with pyridyl-substituted nitronyl nitroxides, [Cu 2(μ-Me 3CCO 2) 4(NITpPy) 2](C 6H 6) ( 1), [Cu 2(μ-CH 3CO 2) 4(NITpPy) 2] ( 2), and [Cu 2(μ-C 6H 6CH 2CO 2) 4(NITmPy) 2] ( 3) (NITpPy=4,4,5,5-tetramethyl-2-(4-pyridyl)-2-imidazoline-N 1-oxyl N 3-oxide, NITmPy=4,4,5,5-tetramethyl-2-(3-pyridyl)-2-imidazoline-N 1-oxyl N 3-oxide) are reported. Structures of complexes 1–3 consist of a symmetrical dimeric Cu(II) carboxylate paddle-wheel core and pyridyl nitrogen atoms of radical ligands at the apical position. Cryomagnetic susceptibilities were measured in the temperature range 4–300 K. According to the structural results, the magnetic data are discussed in terms of four S=1/2 spin units involving one strong coupled dicopper(II) unit plus two monomer nitroxyl radicals. It is found that two paddle-wheel copper(II) ions are strongly coupled antiferromagnetically with J=−192, −172, and −160 cm −1 for complexes 1, 2, and 3, respectively, while the interactions between copper(II) and the radicals are very weak. The magneto–structural correlations for complexes 1, 2, and 3 are discussed on the basis of the structural parameters and magnetic data for the complexes

A novel chain complex of dicopper(II) trimethylacetate linked by pyridyl nitronyl nitroxide

A chain complex of dicopper(II) trimethylactate linked by the pyridyl nitronyl nitroxide [Cu 2(Me 3CCO 2) 4(NITmPy)] n (NITmPy=2-(3-pyridyl)-4,4,5,5-tetramethyl-4,5-dihydro-1 H-imidazolyl-1-oxyl 3-oxide) has been prepared and characterized by X-ray crystal structure analysis. The structure is based on a tetracarboxylate-bridged dimer unit of paddle-wheel copper(II) type but is extended into an infinite zigzag chain via the oxygen and nitrogen atoms of the bridging NITmPy radical ligands. The variable-temperature magnetic susceptibility data show that a strong antiferromagnetic exchange interaction exists between the copper(II) ions.