Copper(I) oxalate complexes: Synthesis, structures and surprises (original) (raw)
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217 A Novel Copper(II)–Hydrogen Oxalate Coordination Polymer
A novel Cu(II) coordination polymer of general empirical formula {[Cu(l-HC 2 O 4 ) 2 (H 2 O) 2 ][Cu(HC 2 O 4 ) 2 ]Á 6H 2 O} n has been synthesized and characterized by single-crystal X-ray diffraction technique. The complex (1) crystallizes in the triclinic form with P-1 space group. It is quite surprising that single crystal X-ray analysis of 1 illustrates the presence of hydrogen oxalate ligand in the coordination environment of Cu(II) ion. Because oxalate is not present in the starting reaction mixture, it may be derived from the reduction of squarate ligand. In 1, Cu(II) ions exhibit two different coordination environments, forming a distorted octahedral geometry. The Cu1 is coordinated with six oxygen atoms from two bidentate HC 2 O 4 and two aqua ligands, while Cu2 is coordinated with six oxygen atoms from four HC 2 O 4 ligands. The HC 2 O 4 ligand acts in two different coordination modes, as a bidentate and an unprecedented tridentate bridging coordination mode.
A new [Cu(ox)(Im)2] complex resulting from the oxidation of chelidonate to oxalate
Journal of Molecular Structure, 2010
We report herein the solid state structure of a new complex [Cu(ox)(Im)2] (II) which adopts a mononuclear 0D form in contrast to the polymeric 1D form adopted by the previously described [Cu(ox)(Im)2]∞1 (I). Both compounds were obtained from an oxidative transformation of chelidonate to oxalate in the presence of Cu(II) and imidazole. The packing and weak interactions of II are
Inorganic Chemistry, 2006
The use of a strategy combining ligand design and changes of reaction conditions has been investigated with the goal of directing the assembly of mononuclear, dinuclear, tetranuclear, and polymeric copper(II) complexes. As a result, closely related copper monomers, alkoxo dimers, and hydroxo cubanes, along with a carbonate-bridged polymeric species, have been synthesized using the rigid, aliphatic amino ligands cis-3,5-diamino-transhydroxycyclohexane (DAHC), cis-3,5-diamino-trans-methoxycyclohexane (DAMC), and the glutaryl-linked derivative glutaric acid bis-(cis-3,5-diaminocyclohexyl) ester (GADACE). The composition of the monomeric complex has been determined by X-ray crystallography as [Cu 2 ](ClO 4 ) 2 (1), the two dimers as [{Cu(DAHC)(OMe)} 2 ]-(ClO 4 ) 2 ‚MeOH (2) and [{Cu(DAMC)(OMe)(ClO 4 )} 2 ] (3), the three Cu 4 O 4 cubanes as [{Cu(DAHC)(OH)} 4 ](ClO 4 ) 4 ‚ 2.5MeOH (4), [{Cu(DAMC)(OH)} 4 ](ClO 4 ) 4 ‚H 2 O (5), and [{Cu 2 (OH) 2 (GADACE)} 2 ]Cl 4 ‚2MeOH‚6H 2 O (6), and an infinitechain structure as [{Cu(DAHC)(CO 3 )} n ] . Furthermore, the cubane structures 4 and 5 have been investigated magnetically. Our studies indicate that formation of the monomeric, dimeric, and tetranuclear DAHC and DAMC complexes can be controlled by small changes in reaction conditions and that further preorganization of the ligand moiety by linking the DAHC cores (GADACE) allows more effective direction of the self-assembly of the Cu 4 O 4 cubane core.
A dinuclear copper (II) complex based on bridging oxalate and single dicyanamide
Indian journal of chemistry. Sect. A: Inorganic, physical, theoretical & analytical, 2004
Résumé/Abstract A discrete dinuclear species [Cu 2 (dca)(ox)(tmen) 2](ClO 4)[dca= dicyanamide, ox= oxalate and tmen= N, N, N', N'-tetramethylethane-1, 2-diamine] representing a rare example of a complex having bridging oxalate and single dicyanamide between two metal centres, has been synthesised and characterised by X-ray single crystal structure determination and low temperature magnetic measurements.
Polyhedron, 2001
The neutral polymeric complexes of copper(II) [CuL 2 (4,4%-bipy)] n , where L is an a-hydroxycarboxylato ligand, lactate in 1, 2-methyllactate in 2, were prepared and characterised structurally. The copper atom is in an elongated tetragonally distorted octahedral environment in both compounds. Both a-hydroxycarboxylato ligands are O,O%-bidentate chelating monoanions and 4,4%-bipyridine acts as an N,N%-bis(monodentate) bridging ligand creating a linear polymeric arrangement. The polymeric chains are interconnected by O hydroxyl H···O carboxy hydrogen bonds in a way that creates cavities that differ in size between 1 and 2. Spectroscopic data are presented and discussed.
Inorganic Chemistry, 1992
mononuclear complexes that we have isolated as tetra-and pentahydrate sodium salts, respectively. The synthesis of M2L complexes was carried out in the light of the respective distribution diagrams based on fitted equilibrium constants (Figures 4 and 5). In order to obtain single crystals of such species, aqueous solutions of copper(I1) nitrate (nickel(I1) nitrate) and H4L in a 2: 1 molar ratio were prepared a t p H = 3. In the case of copper(II), the slow polymerization of Cu(H2L) leads to the insoluble polymeric complex 1. Nevertheless, Cu2-L.6H20 can be isolated as a powder in weakly acidic aqueous solutions. The nonpolymerization of the Ni(H2L) species allows in this case the formation of single crystals of the insoluble complex 2 in nearly neutral aqueous solutions. Conclusions. The versatility of N,N'-disubstituted oxamides has allowed the synthesis of mono-, di-, and polynuclear complexes. Strong antiferromagnetic coupling is observed in the poxamidato polynuclear compounds. This work shows how one must be careful when using the n21J1 values to estimate the magnitude of the exchange coupling in binuclear nickel(I1) complexes from the known values for the corresponding copper(I1) complexes through a given bridge. Although nickel(II)-oxamide complexes are usually diamagnetic, paramagnetic nickel(11) species can be obtained by tuning the strength of the ligand field using as tools appropriate N-substituted derivatives and angular strain. Finally, this report provides a new example of complementarity between solution and solid-state studies, showing how solution data can orientate the synthetic work in order to obtain the desired products. Acknowledgment. This work was partially suppprted by the Comisidn Interministerial de Ciencia y Tecnologia (Proyecto PB88-0490) and the Programa de Acciones Integradas Hispano-Francesas. R.R. acknowledges the Conselleria de Cultura, Educacid i C i h c i a de la Generalitat Valenciana for a grant.
Oxalato complexes of copper(II) with chelating diamines. Crystal structure of [Cu(dmen)ox(H2O)]2Cu(dmen)22
Polyhedron, 2002
Four new oxalato complexes of copper(II) of composition [Cu(dmen)ox(H 2 O)] 2 [Cu(dmen) 2 ](ClO 4 ) 2 (1) (dmen 0/N ,Ndimethylethylenediamine, H 2 ox0/oxalic acid), [(Cu(dmen)H 2 O) 2 ox](ClO 4 ) 2 ×/H 2 O (2), [Cu(tmen)(H 2 O)(ox)Cu(aep)(H 2 O)](ClO 4 ) 2 (3) (tmen 0/N ,N ,N ?,N ?-tetramethylethylenediamine, aep0/2-(2-aminoethyl)pyridine) and [(Cu(dben)NO 3 ) 2 ox] (4) (dben 0/N ,N ?dibenzylethylenediamine) have been prepared and characterised by IR and UV Á/Vis spectroscopies and magnetic measurements. The crystal structure of [Cu(dmen)ox(H 2 O)] 2 [Cu(dmen) 2 ](ClO 4 ) 2 (1) has been determined by single-crystal X-ray analysis. The structure of 1 contains a neutral [Cu(dmen)ox(H 2 O)] complex, a cationic [Cu(dmen) 2 ] 2' complex and perchlorate anions. The copper(II) atom of the neutral [Cu(dmen)ox(H 2 O)] unit possesses a distorted square-pyramidal environment with two oxygen atoms of oxalate and two nitrogen atoms of dmen in the basal plane and an oxygen atom of a water molecule in the apical position. The copper(II) atom of the cationic [Cu(dmen) 2 ] unit shows a square-planar environment with four donor nitrogen atoms of two molecules of dmen. The temperature dependence of magnetic susceptibility for compounds 2 Á/4 was measured. Magnetochemical measurements show that copper(II) ions in compounds 2 Á/4 are antiferromagnetically coupled through the oxalate bridge, J 0/ (/157, (/175 and (/167 cm (1 (H 0/(/2JS 1 S 2 , S 1 0/S 2 0/1/2) for 2, 3 and 4, respectively. #
International Journal of Molecular Sciences, 2006
The synthesis and crystal structure of Cu(II) complex of a binucleating tridentate ligand 1,3-bis [N,N-bis(2-picolyl)amino]propan-2-ol (I) is being reported. The two chelating bispicolylamine arms in I are tethered by a 2-hydroxypropyl group with Cu(II) coordinating in a slightly distorted square planar geometry to give [Cu 2 (I)(OH 2 )(Cl)](ClO 4 ) 3 ·2H 2 O (II). The crystal data for II: Triclinic, space group Pī with cell dimensions of a = 13.345 (4) Å, b = 13.873 (4) Å, c = 12.867 (2) Å, α = 111.68 (2)°, β = 100.34 (2)°, γ = 65.83 (2)°, V = 2018.4 (9) Å 3 , F.W. = 962.46, ρ calc = 1.583 g cm -3 for Z = 2, µ = 13.93 cm -1
A novel Cu(II) coordination polymer, [Cu(ox)(DMSO) 2 ] n (1) (ox-oxalate dianion, DMSO-dimethyl sulphoxide) has been prepared in the reaction of copper nitrate dihydrate and allantoin (5-ureidohydantoin) in DMSO/water solution. Compound (1) crystallizes in the monoclinic, space group P121/c1 with a = 5.1785 , b = 13.6311(18), c = 8.5386(12) Å, b = 107.524(12)°, V = 574,76(14) Å 3 , Z = 4, D cal = 1779 mg/m 3 , R 1 = 0.0449. The metal ion coordinates through four oxygen atoms belonging to two bidentate bridging oxalate ligands, and two oxygen atoms from two DMSO ligands forming an elongated octahedron. The crystal structure was confirmed by FT-IR and Uv-vis spectroscopic data.
Z. Anorg. Allg. Chem. 643 (2017) 276 - 285, 2017
Blue single crystals of Cu[µ2-OOC(CH2)PO3H]*2H2O (1) and Cu1.5[µ3-OOC(CH2)PO3]*5H2O (2) have been prepared in aqueous solution. 1: Space group C2/c (no. 15) with a = 1623.3(2), b = 624.0(1), c = 1495.5(2) pm, beta = 122.45(1)°. Cu is coordinated by three oxygen atoms stemming from the hydrogenphosphonoacetate dianion and three water molecules to form a distorted octahedron. The Cu-O bonds range from 190.4(3) to 278.5(3) pm. The connection between the Cu2+ cations and the hydrogenphosphonoacetate dianions leads to a two-dimensional structure with layers parallel to ( 01). The layers are linked by hydrogen bonds. 2: Space group (no. 2) with a = 608.2(1), b = 800.1(1), c = 1083.6(1) pm, alpha = 94.98(1)°, beta = 105.71(1)°, gamma = 109.84(1)°. There are two crystallographically independent Cu2+ cations coordinated in a square pyramidal and an octahedral fashion, respectively. The Cu-O bonds range from 192.9(2) to 237.2(2) pm. The coordination of the phosphonoacetate trianion to Cu(1) results in infinite polyanionic chains parallel to [100] with a composition of {Cu(H2O)[OOC(CH2)PO3]}nn. Hydrated Cu(2) cations are accommodated between the chains as counter ions. 1 and 2 show structural features of cation exchangers. Magnetic measurements reveal a paramagnetic Curie-Weiss behaviour. Compound 2 shows antiferromagnetic coupling between Cu2+ ions due to a super-superexchange coupling. The UV/Vis spectra of 1 suggests three d-d transition bands at 763 nm (2B1 -> 2E), 878 nm (2B1 -> 2B2), and 1061 nm (2B1 -> 2A1). Thermoanalytical investigations in air show that compound 1 is stable up to 165 °C, whereas the decomposition of 2 begins at 63 °C.