Synthesis, structural and magnetic properties of macrocyclic aza-amido binuclear copper(II) complexes

1989 ◽  
Vol 67 (4) ◽  
pp. 662-670 ◽  
Author(s):  
Sanat K. Mandal ◽  
Laurence K. Thompson ◽  
Michael J. Newlands ◽  
Amal K. Biswas ◽  
Bibhutosh Adhikary ◽  
...  
Keyword(s):  
Variable Temperature ◽  
Complex Iii ◽  
Azomethine Nitrogen ◽  
X Ray Diffraction ◽  
Binuclear Copper ◽  
Magnetic Studies ◽  
Monoclinic System ◽  
Space Group ◽  
Pyramidal Geometry ◽  
Square Planar

Binuclear, antiferromagnetically coupled, macrocyclic copper(II) complexes, [Cu2(C28H32N4O4)]•H2O (II) and [Cu2(C36H32N4O4)]•CH3CN•H2O (III), involving asymmetric ligands with two deprotonated amide, two azomethine nitrogen, and two phenoxide donors at the binuclear centre, have been synthesized and characterized by single-crystal X-ray diffraction and variable temperature magnetic studies. Complex II crystallizes in the monoclinic system, space group P21/n, with a = 16.4854(9) Å, b = 7.6005(13) Å, c = 21.1617(11) Å, β = 104.090(5)°, Z = 4, Rf = 0.068 for 2062 significant reflections. The two copper(II) centres have square planar N2O2 donor sets with two phenoxide oxygen atoms bridging the copper centres with a copper–copper separation of 2.898(2) Å. A long copper–oxygen (amide) contact (2.808(10) Å) forms a weak dimer association. Complex III crystallizes in the triclinic system, space group [Formula: see text], with a = 8.7771(9) Å, b = 12.3983(16) Å, c = 15.7299(16) Å, α = 85.003(11)°, β = 84.574(8)°, γ = 76.838(10)°, Z = 2, Rf = 0.041 for 2966 significant reflections. The two copper(II) centres have distorted square-pyramidal geometry involving an N2O2 in plane donor set and two phenoxide oxygen bridges with a copper–copper separation of 3.018(1) Å. The fifth coordination site at each copper centre involves an amide oxygen from a neighbouring molecule (Cu(1)—O 2.371(4), Cu(2)—O 2.413(3) Å) in a staggered intermolecular array. Very strong antiferromagnetic exchange is observed in both cases (−2J = 689 ± 7 cm−1 (II), −2J = 816 ± 8 cm−1 (III)). Keywords: macrocycles, binuclear copper(II) complexes.

The structures and phase transitions in 4-aminopyridinium tetraaquabis(sulfato)iron(III), (C5H7N2)[FeIII(H2O)4(SO4)2]

2019 ◽  
Vol 75 (6) ◽  
pp. 1144-1151
Author(s):  
Tamara J. Bednarchuk ◽  
Wolfgang Hornfeck ◽  
Vasyl Kinzhybalo ◽  
Zhengyang Zhou ◽  
Michal Dušek ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Single Crystal ◽  
Room Temperature ◽  
Variable Temperature ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Hybrid Compound ◽  
Space Group ◽  
X Ray

The organic–inorganic hybrid compound 4-aminopyridinium tetraaquabis(sulfato)iron(III), (C5H7N2)[FeIII(H2O)4(SO4)2] (4apFeS), was obtained by slow evaporation of the solvent at room temperature and characterized by single-crystal X-ray diffraction in the temperature range from 290 to 80 K. Differential scanning calorimetry revealed that the title compound undergoes a sequence of three reversible phase transitions, which has been verified by variable-temperature X-ray diffraction analysis during cooling–heating cycles over the temperature ranges 290–100–290 K. In the room-temperature phase (I), space group C2/c, oxygen atoms from the closest Fe-atom environment (octahedral) were disordered over two equivalent positions around a twofold axis. Two intermediate phases (II), (III) were solved and refined as incommensurately modulated structures, employing the superspace formalism applied to single-crystal X-ray diffraction data. Both structures can be described in the (3+1)-dimensional monoclinic X2/c(α,0,γ)0s superspace group (where X is ½, ½, 0, ½) with modulation wavevectors q = (0.2943, 0, 0.5640) and q = (0.3366, 0, 0.5544) for phases (II) and (III), respectively. The completely ordered low-temperature phase (IV) was refined with the twinning model in the triclinic P{\overline 1} space group, revealing the existence of two domains. The dynamics of the disordered anionic substructure in the 4apFeS crystal seems to play an essential role in the phase transition mechanisms. The discrete organic moieties were found to be fully ordered even at room temperature.

Structure and magnetism in a hydroxy bridged binuclear copper(II) system with a "tunable" binuclear centre

1983 ◽  
Vol 61 (3) ◽  
pp. 579-583 ◽  
Author(s):  
Laurence K. Thompson
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Coordination Geometry ◽  
Antiferromagnetic Exchange ◽  
X Ray Diffraction ◽  
Binuclear Copper ◽  
Space Group ◽  
X Ray ◽  
Oxygen Bridge ◽  
Copper Coordination

The molecular structure of [Cu2(PAP)(OH)(IO3)3]•4H2O (PAP = 1,4-di(2′-pyridyl)aminophthalazine) has been determined by single crystal X-ray diffraction. [Cu2(PAP)(OH)(IO3)3]•4H2O belongs to the space group P21/c with a = 7.266(1), b = 15.269(1), c = 25.870(1) Å, β = 96.40(I)°, V = 2852.2 Å3, Z = 4. The copper coordination geometry lies between a square pyramid and a trigonal bipyramid and the two copper(II) centres are bridged by three groups: N2 (phthalazine), hydroxide, and bidentate iodate, in a structure which is analogous to that reported for [Cu2(PAP)(OH)Cl3]•1.5H2O. Replacing the chlorine bridge by iodate has the effect of forcing the two metal centres further apart, thus creating a larger Cu—O—Cu bridge angle. This increase in oxygen bridge angle (101° to 114°) is also reflected in the enhanced antiferromagnetic exchange (−2J(Cl) = 201 cm−1, −2J(IO3) = 335 cm−1). Other groups of varying size (e.g. Br, NO3, SO4) can act as bridges between the two copper centres in systems of this sort with the resultant variation in copper–copper separation and oxygen bridge angle.

scholarly journals Synthesis and Characterisation of New Symmetrical Binucleating Ligands and Their Binuclear Copper(II) Complexes

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
K. Jothivenkatachalam ◽  
S. Chandra Mohan
Keyword(s):  
Electron Transfer ◽  
Exchange Interaction ◽  
Variable Temperature ◽  
Esr Spectra ◽  
Single Step ◽  
Binuclear Copper ◽  
Magnetic Studies ◽  
Weak Exchange ◽  
Broad Signal ◽  
Binucleating Ligands

New symmetrical binucleating ligands N,N-bis[2-hydroxy-5-methyl-3-(4-methyl-piperazinomethyl)benzyl]-alkylamines L1 and L2 and their copper(II) complexes [Cu2L(X)2]·2H2O, where X = CH3COO−, C6H5COO−, Cl−, and ClO4-, were prepared and characterised. All the complexes undergo quasi-reversible reduction at negative potential (E = −0.48 to −1.02 V). The acetate and benzoate complexes undergo a two-step single electron transfer at –0.48 to –0.60 V and −0.9 to −1.02 V. The chloro and perchlorate complexes undergo a single step two-electron transfer at −0.55 to −0.75 V. Variable temperature magnetic studies show the presence of weak exchange interaction for acetate (−2 J around 25 to 40 cm−1) and benzoate (−2 J around 45 to 55 cm−1) bridged complexes and no exchange interaction is found for chloro and perchlorate complexes. ESR spectra of chloro and perchlorate complexes are like mononuclear copper(II) complexes with hyperfine splitting (A = 165 ± 5, g∥ = 2.17–2.23, and g⊥ = 2.05–2.10). The ESR spectra of acetate and benzoate complexes are like binuclear copper(II) complexes with broad signal (g = 2.2).

Synthesis, Crystal Structure and Magnetic Properties of a (μ-Hydroxo)(μ-Pyrazolato) Dicopper(II) Complex

2000 ◽  
Vol 55 (9) ◽  
pp. 796-802 ◽  
Author(s):  
H. Kara ◽  
Y. Elerman ◽  
K. Prout
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Variable Temperature ◽  
Powdered Sample ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Present Complex ◽  
Square Planar ◽  
Super Exchange Interaction

Preparation and magnetic properties of a 3,5-dimethylpyrazolate bridged binuclear copper(II) complex [Cu2(L)(3 ,5 -pyz)] (L = 1,3-Bis(2-Hydroxy-5-Chlorosalicylideneamino)propan- 2-ol) is reported. The crystal structure determined by X-ray diffraction methods. (C22H20N4O3CI2CU2), triclinic, space group P1̄, a = 9.622(3), b = 10.921(2), c = 11.420(3) Å, α = 100.73(2), β = 94.04(2), Υ = 108.08(2)°, V = 1110.2(5) Å3, Z = 2. Two copper(II) ions in a square-planar coordination are bridged via alkoxide oxygen and 3,5-dimethyl pyrozolate nitrogen atoms to form a dinuclear unit. The metal coordination sphere is four-coordinate, planar with an N2O2 donor set. The dihedral angle between the two coordination planes is 166.83°. There are significant intermolecular interactions between neighbouring binuclear entities. The shortest intermolecular Cu (1) ... Cu(1)i distance is 3.383(1) Å and the Cu(1) - O ( 1)i distance is 2.666(3) Å (i = 1 -x, -y, 1 - z). The variable-temperature magnetic susceptibility measurement for a powdered sample of the complex was carried out in the temperature range 5 - 350 K and analysed to obtain values of the parameter J in the exchange Hamiltonian ℋ = -2JScu Scu; 2J = -164 cm-1. The magnetic moment at 300 K is about 2.42 μB, and 0.22 μB at 5 K. The weak antiferromagnetism of the present complex is reasonably explained in terms of the orbital countercomplementary effect based on Hoffmann's theory for super-exchange interaction

Oligometallic cobalt 3,5-dimethylpyrazolate complexes: synthesis, structural and magnetic studies

1993 ◽  
Vol 71 (9) ◽  
pp. 1425-1436 ◽  
Author(s):  
Martin K. Ehlert ◽  
Steven J. Rettig ◽  
Alan Storr ◽  
Robert C. Thompson ◽  
James Trotter
Keyword(s):  
Magnetic Data ◽  
Antiferromagnetic Coupling ◽  
Antiferromagnetic Exchange ◽  
Nearest Neighbour ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Dimer Model ◽  
Space Group ◽  
X Ray ◽  
Susceptibility Data

Three oligometallic 3,5-dimethylpyrazolate (dmpz) bridged Co(II) compounds have been synthesized and characterized spectroscopically: dimeric [Co(dmpz)2(Hdmpz)]2, the related oligometallic compound, Co(dmpz)2•0.344(Hdmpz), and the trimetallic [Co(dmpz)2Cl(Hdmpz)]2Co. The first and last of these compounds have been studied magnetically and by single crystal X-ray diffraction. Crystals of [Co(dmpz)2(Hdmpz)]2 are orthorhombic, a = 17.022(1), b = 29.224(2), c = 13.576(3) Å, Z = 8, space group Fddd; and those of [Co(dmpz)2Cl(Hdmpz)]2Co are triclinic, a = 11.742(3), b = 18.604(4), c = 8.950(2) Å, α = 99.76(2)°, β = 102.32(2)°, γ = 93.36(2)°, Z = 2, space group [Formula: see text] The structures were solved by the Patterson method and were refined by full-matrix least-squares procedures to R = 0.035 and 0.042 (Rw = 0.034, 0.047) for 938 and 3853 reflections with I ≥ 3σ(F2), respectively. Magnetic susceptibility studies on the dimeric and trimetallic complex show them to exhibit antiferromagnetic behaviour. Analysis of the magnetic data (2– 300 K) for the trimetallic complexes reveals antiferromagnetic coupling between the terminal and central Co(II) ions with J (Heisenberg) ≈ −3 cm−1. Either intramolecular next-nearest neighbour or intermolecular antiferromagnetic exchange is also present in this compound. The dimeric complex shows significant antiferromagnetic exchange between cobalt centres. Susceptibility data over the range 12–300 K are adequately modelled with the Ising S = 1/2 dimer model (J ≈ −23 cm−1).

Copper, Thioamide Complexes. Syntheses and Structures of Di-m-chloro-bis[N-(pyridin-2-yl)benzenecarbothioamide-S,N']dicopper(I) and of Bis[N-(pyridin-2-yl)benzenecarbothioamide-S,N']copper(I) Chloride, Complxes Containing Tetrahedrally Coordinated Copper Centres

1985 ◽  
Vol 38 (6) ◽  
pp. 865 ◽  
Author(s):  
MW Fuller ◽  
V Costanzo ◽  
KS Murray ◽  
DSC Black ◽  
TW Hambly ◽  
...  
Keyword(s):  
Single Crystal ◽  
X Ray Diffraction ◽  
Binuclear Copper ◽  
Chlorine Atoms ◽  
Space Group ◽  
X Ray ◽  
Thioamide Group ◽  
Excess Copper ◽  
Pyridine Nitrogen ◽  
Yellow Compound

The mononuclear copper(I) complex Cu(PhCSNHC5H4N)2Cl (Cu( pbctaH )2Cl) and the binuclear copper(I) complex [Cu(PhCSNHC5H4N) Cl ]2 ([Cu( pbctaH ) Cl ]2) have been prepared from copper(II) chloride and N-(pyridin-2- yl ) benzenecarbothioamide ( pbctaH ) and their structures detertnined by single-crystal X-ray diffraction studies. Cu(PhCSNHC5H4)2Cl crystallizes in the space group C2/c with the parameters a 28.042(3) Ǻ, b 6.385(a) Ǻ, c 14.158(12) Ǻ, β 117.01(1)°. The stereochemistry about the copper is essentially tetrahedral, with coordination occurring through the pyridine nitrogen and the sulfur of the thioamide group, and an NCuS angle of 95.7(1)°. [Cu(PhCSNHC5H4N)2Cl]2 crystallizes in the space group C2/c with the parameters a 16.538(6) Ǻ, b 9.135(4) Ǻ, c 16.470(6) Ǻ, β 93.925(15)°. The crystal is made up of binuclear chloro -bridged units, the essentially tetrahedral stereochemistry about the copper atoms being completed by coordination from the pyridine nitrogen and the sulfur of the thioamide group, with an NCuS angle of 99.5(1)°. The Cu2Cl2 group is non-planar, with the copper atoms 0.133 Ǻ above and the chlorine atoms 0.133 Ǻ below the average plane. Other complexes can be isolated from reactions of excess copper(II) chloride with ligand although their structures have not been characterized. A diamagnetic orange compound and a paramagnetic yellow compound apparently derived from copper(n) oxidation of the thioamide were also obtained. Other products, prepared under more basic conditions, are also described. No stable copper(II) complexes of the parent thioamide could be isolated. Use of a 4-nitro substituted benzenecarbothioamide ligand did, however, produce a bis-chelated copper(II) complex.

Dodecamethyl Bisimidotriphosphoramide (TRIPA), Part III [1, 2] The Crystal and Molecular Structure of TRIPA · H2O

1980 ◽  
Vol 35 (10) ◽  
pp. 1203-1206 ◽  
Author(s):  
Johannes C. P. M. Lapidaire ◽  
Anthoni J. De Kok
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Crystal And Molecular Structure ◽  
Van Der Waals ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray

Abstract The crystal and molecular structure of dodecamethyl bisimidotriphosphoramide mono-hydrate (TRIPA • H2O, C12H38N7O4P3) has been determined by single crystal X-ray diffraction techniques. The compound crystallises in the monoclinic system, space group P2i/n with a = 9.236(3), b = 14.016(4), c = 17.534(5) A, β = 97.32(4)°, Z = 4. The building units are dimers of TRIPA • H2O. These units are separated by normal van der Waals distances. The two molecules in the dimer are connected by four hydrogen bridges involving two water molecules. The nitrogen atoms display a nearly planar hybridisation.

Crystal Structure of Dibromo(η4-1,5-cyclooctadiene)palladium(II)

1996 ◽  
Vol 61 (9) ◽  
pp. 1335-1341 ◽  
Author(s):  
Petr Štěpnička ◽  
Ivana Císařová
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Boat Conformation ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Square Planar ◽  
Twisted Boat

The crystal structure of [(η4-C8H12)PdBr2] has been determined by a single crystal X-ray diffraction with R = 3.82% for 2 147 independent diffractions. The compound crystallizes with the symmetry of orthorhombic space group P212121 (No. 19) within the following parameters: a = 7.0785(5) Å, b = 11.1896(9) Å, c = 12.514(1) Å, V = 991.2(1) Å3, Z = 4. The square planar arrangement of ligands around Pd(II) is distorted due to the steric requirements of 1,5-cyclooctadiene in a twisted boat conformation. Formula units are joined by the weak C2-H2...Br1(1 + x, y, z) hydrogen bonds.

Synthesis and X-ray diffraction data of 1-N-(4-pyridylmethyl)amino naphthalene

2010 ◽  
Vol 25 (1) ◽  
pp. 72-74 ◽  
Author(s):  
H. A. Camargo ◽  
J. A. Henao ◽  
D. F. Amado ◽  
V. V. Kouznetsov
Keyword(s):  
Diffraction Pattern ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

1-N-(4-pyridylmethyl)amino naphtalene was synthesized by means of a reaction of alpha-naphthylamine, 4-pyridylcarboxyaldehyde, in anhydrous ethanol to obtainN-(4-pyridylen)-alpha-naphthylamine and that was reduced with NaBH4 to produce the wanted compound. The X-ray powder diffraction pattern for the new compound 1-N-(4-pyrydylmethyl)amino naphtalene was obtained. This compound crystallizes in a monoclinic system with refined unit cell parameters a=10.375(5) Å, b=17.665(6) Å, c=5.566(2) Å, β=100.11(3), and V=1004.3(5) Å3, with space group P2/m (No. 10).

Powder diffraction investigations of naphthalenesulfonic acids and their complexes with DMAN

2004 ◽  
Vol 19 (4) ◽  
pp. 378-384
Author(s):  
A. Rafalska-Lasocha ◽  
M. Grzywa ◽  
B. Włodarczyk-Gajda ◽  
W. Lasocha
Keyword(s):  
Powder Diffraction ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Acid Hydrate ◽  
M 12 ◽  
Diffraction Patterns

The X-ray diffraction patterns of two organic acids 1-naphthalenesulfonic acid dihydrate and 2-naphthalenesulfonic acid hydrate were measured at room temperature. Complexes of these acids with 1,8-bis(dimethylamino)naphthalene (DMAN) were synthesized, purified and investigated by means of X-ray powder diffraction. 1-Naphthalenesulfonic acid dihydrate as well as its complex with 1,8-bis(dimethylamino)naphthalene crystallize in the monoclinic system with unit cell parameters refined to a=0.91531(8) nm, b=0.7919(1) nm, c=0.8184(1) nm, β=101.618(9)° space group P21/m (11) and a=1.7781(4) nm, b=2.0122(4) nm, c=1.2337(2) nm, β=96.54(3)°, space group C2/m (12), respectively. 2-Naphthalenesulfonic acid hydrate crystallizes in the orthorhombic system with a=2.2749(3) nm, b=0.7745(1) nm, c=0.591 36(9) nm, space group Pnma, whereas its complex with 1,8-bis(dimethylamino)naphthalene crystallizes in the triclinic system a=1.3969(6) nm, b=1.4292(5) nm, c=1.1741(6) nm, α=90.93(3)°, β=98.14(3)°, γ=113.93(3)°, space group P-1 (2).

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