Three 3d–4f Tetranuclear Complexes Based on 2,3,5-Trichlorobenzoic Acid: Syntheses, Structures, and Magnetic Properties

2016 ◽  
Vol 69 (4) ◽  
pp. 446 ◽  
Author(s):  
Yu Zhang ◽  
Ji-Min Zheng

The solvothermal reactions of 2,3,5-trichlorobenzoic acid (HL) 2,2′-bipyridine (bipy), CoCl2·6H2O, and Ln2O3 afforded three novel 3d–4f tetranuclear complexes Co2Ln2(L)10(bipy)2 (Ln = Dy 1, Ho 2, and Er 3), which have been characterized by single-crystal X-ray diffraction, infrared spectroscopy, and element analyses. Complexes 1–3 crystallize in the triclinic space group P1, and the completely deprotonated L ligands possess μ2 : η2, η1 and μ2 : η1, η1 coordination modes to bridge adjacent metal ions, which further connect into 2D layers by hydrogen bonds. Magnetic studies indicate ferromagnetic interactions between adjacent metal ions in complexes 1 and 3.

2018 ◽  
Vol 73 (8) ◽  
pp. 571-575
Author(s):  
Yang Jie ◽  
Huang Yuan ◽  
Zhong YouQuan ◽  
Fang Ting ◽  
Hao Fan ◽  
...  

AbstractA new complex [(CH3)3NH]2[Co(NCS)4], in which zero-dimensional [Co(NCS)4]n2− anions are balanced by 2n [(CH3)3NH]+ cations, was synthesized. The complex has been characterized by single X-ray diffraction, infrared spectroscopy, elemental analysis, and magnetic measurements. Magnetic susceptibility data indicate ferromagnetic interactions among the CoII ions.


2020 ◽  
Author(s):  
Roberto Köferstein

Two bis(oxalato)cuprate(II) hybrid salts, (C5H7N2)2[Cu(C2O4)2]·2H2O (1) and(C7H11N2)2[Cu(C2O4)2]·5H2O (2) (C5H7N2 = 3-aminopyridinium; C7H11N2 = 2-amino-4,6-dimethylpyridinium) have been synthesized and characterized by elemental and thermalanalyses, IR and UV-Vis spectroscopies, single-crystal X-ray diffraction, and SQUID magnetometry. The polymeric anionic motifs in the two salts are significantly different. In 1, stacking of [Cu(C2O4)2]2- units through axial Cu···O contacts (2.890 Å) yields straight Cu(II) chains, with a prolate CuO6 octahedron around Cu(II) ions, formed by two cis-chelated oxalate anions and two axial O-atoms of neighboring [Cu(C2O4)2]2- units. By contrast, in 2,stacking of [Cu(C2O4)2]2- units occurs via bis-bidentate oxalate groups, yielding zigzag Cu(II) chains with a distorted CuO6 coordination sphere. Thermal studies confirmed the presence of solvent water molecules in both salts. Magnetic studies revealed weak antiferromagnetic and weak ferromagnetic interactions between Cu(II) ions in 1 and 2, respectively.


2005 ◽  
Vol 60 (9) ◽  
pp. 978-983 ◽  
Author(s):  
Sevim Hamamci ◽  
Veysel T. Yilmaz ◽  
William T. A. Harrison

Two new saccharinato-silver(I) (sac) complexes, [Ag(sac)(ampy)] (1), and [Ag2(sac)2(μ-aepy)2] (2), [ampy = 2-(aminomethyl)pyridine, aepy = 2-(2-aminoethyl)pyridine], have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and triclinic space group P1̄, respectively. The silver(I) ions in both complexes 1 and 2 exhibit a distorted T-shaped AgN3 coordination geometry. 1 consists of individual molecules connected into chains by N-H···O hydrogen bonds. There are two crystallographically distinct dimers in the unit cell of 2 and in each dimer, the aepy ligands act as a bridge between two silver(I) centers, resulting in short argentophilic contacts [Ag1···Ag1 = 3.0199(4) Å and Ag2···Ag2 = 2.9894(4) Å ]. Symmetry equivalent dimers of 2 are connected by N-H···O hydrogen bonds into chains, which are further linked by aromatic π(py)···π(py) stacking interactions into sheets.


2000 ◽  
Vol 55 (3-4) ◽  
pp. 299-316 ◽  
Author(s):  
Dagmar Henschel ◽  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones

Abstract In a study aim ed at the „deconstruction“ of the supramolecular aggregate 3(18C6) · 2HN( SO2Me)2 (1,18C6 = 18-crown-6), which is known to display a ladder structure with two isotactic [18C6 - Me SO2N(H)SO2Me···)∞ polymers forming the uprights and symmetrically N - H···O bonded 18C6 rings providing the rungs, the following crystalline complexes were isolated and (except for 2b) characterized by low-temperature X-ray diffraction: 18C6-ClN (SO2Me)2 (2a, triclinic, space group P1̅, Z = 2), 18C6-PhN (SO2Me)2 (2b), 18C6 -MeN(SO2Me)2 (3, monoclinic, P21/c, Z = 8), Bz18C6-HN(SO2Me)2 (4, Bz18C6 = benzo-18-crown-6, monoclinic, P21/n, Z = 4), 18C6-2 MeN (SO2Me)2 (5, triclinic, P1̅, Z = 1), 18C6-Me2SO- HN( SO2Me) (SO2Ph) (13, triclinic, P1̅, Z = 2), and 18C6-H2OMe2SO·2HN(SO2Me)2 (14, triclinic, P1̅, Z = 2). Each of the one-dimensional polymers 2a (syndiotactic), 3 (disyndiotactic) and 4 (isotactic) mimics a single upright of 1; in contrast to 1 and 2a, where the intra-catemer connectivity solely relies on S - Me ··· crow n and crown ··· O = S hydrogen bonds, this bonding system is reinforced in 3 by N -Me ··· crown and in 4 by N - H ··· crown hydrogen bonds. Complex 5 is monomeric and matches a fragment formally extruded from the catemer 3; moreover, 3 and 5 represent a rare case of two structurally characterized 18C6 complexes containing the same uncharged guest species in distinct molecular ratios. The surprising structure of the quaternary adduct 14 exhibits an [18C6 ··· MeSO2N(H)SO2Me ··· ]∞ chain, which can be regarded both as an isolated, though unmodified upright from the ladder 1 and, being syndiotactic, as a stereochemical analogue of 2a; the potentially rung-forming *NH functions in the chain are blocked by hydrogenbonded side chains of the type * N - H ··· water ··· sulfoxide ··· H - N (SO2Me)2. The ternary complex 13 consists of chains [18C6 ··· Me2SO ··· H - N (SO2Ph)SO2Me···]∞ and is not closely related to the other structures


2012 ◽  
Vol 67 (11) ◽  
pp. 1185-1190 ◽  
Author(s):  
Jin-Li Qi ◽  
Wei Xu ◽  
Yue-Qing Zheng

A new Cu(II) complex was prepared at room temperature from the reaction of p-formylbenzoic acid, phenanthroline, CuCl2⋅2H2O, and NaOH under ethanolic aqueous conditions. The complex has been characterized by X-ray diffraction, IR spectroscopy, TG-DTA analyses, and magnetic measurements. Single-crystal X-ray diffraction analysis indicated that the complex crystallizes in the triclinic space group P1̄ with the cell dimensions a=7.875(2), b=10.724(2), c=15.317(3) Å , α =102.65(3), β =93.71(3), γ =107:64(3)°. The Cu atoms are in the environment of distorted CuN2O3 tetragonal pyramids. These discrete complex molecules are packed through intermolecular π...π-stacking interactions and C-H...O hydrogen bonds forming a supramolecular structure. The title complex obeys the Curie-Weiss law with a Curie constant C=0:53 cm3 K mol-1 and a Weiss constant θ = -0:27 K. The shape of the xmT curve is characteristic of weak ferromagnetic interactions between the Cu(II) centers from 300 to 7 K, while there are weak antiferromagnetic interactions below 7 K.


2017 ◽  
Vol 72 (12) ◽  
pp. 937-940 ◽  
Author(s):  
Xiao-Hong Zhu ◽  
Xiao-Chun Cheng ◽  
Yun-Hua Qian

AbstractThe neutral, four-fold protonated pyridine-3,5-dicarbox(3,5-dicarboxylatoanilide) (H4L) reacts with Mn(II) salts under hydrothermal conditions to yield a new complex: [Mn2(L)(H2O)2]·H2O (1), which has been characterized by single crystal X-ray diffraction, infrared spectroscopy, and elemental and thermogravimetric analyses. Complex 1 exhibits a binodal (4,8)-connected 3D framework with flu (412.612.84)(46)2 topology. The magnetic properties of 1 were investigated.


1998 ◽  
Vol 13 (2) ◽  
pp. 451-456 ◽  
Author(s):  
C. Vázquez-Vázquez ◽  
P. Kögerler ◽  
M. A. López-Quintela ◽  
R. D. Sánchez ◽  
J. Rivas

The study of submicroscopic particles in already known systems has resulted in a renewed interest due to the large differences found in their properties when the particle size is reduced, and because of possible new technological applications. In this work we report the preparation of LaFeO3 particles by the sol-gel route, starting from a solution of the corresponding metallic nitrates and using urea as gelificant agent. Gels were decomposed at 200 °C and calcined 3 h at several temperatures, T, in the range 250–1000 °C. The samples were structurally characterized by x-ray diffraction (XRD) showing that the orthoferrite crystallizes at T as low as 315 °C. From the x-ray diffraction peak broadening, the particle size was determined. The size increases from 60 to 300 nm as the calcination T increases. Infrared spectroscopy was used to characterize gels and calcined samples. From these studies a mechanism for the gel formation is proposed. Study of the magnetic properties of LaFeO3 particles shows the presence of a ferromagnetic component which diminishes as the calcination temperature increases, vanishing at T = 1000 °C.


2012 ◽  
Vol 455-456 ◽  
pp. 735-739
Author(s):  
Rui Xin Chen ◽  
Ling Yan Xu ◽  
Chang Feng Sun

A new two-dimensional neutral framework generated from mixed organic ligands [Cu3(1,2,4-BTC)2(4,4/-bipy)(H2O)4] (where1,2,4-BTC = 1,2,4-benzenetricarboxylate), has been prepared under hydrothermal condition and characterized by single crystal X-ray diffraction and magnetic susceptibilities. Its structure contains two different one-dimensional chains for the Cu ions, namely [Cu2(1,2,4-BTC)2]n2n-and [Cu (4,4/-bipy)]n2n+, respectively; the carboxylate of 1,2,4-BTC ligands links the two different 1-D chains into a interesting steplike supramolecular neutral framework, which exists ferromagnetic interactions between the copper centers.


Author(s):  
Shao-Dong Li ◽  
Feng Su ◽  
Cheng-Yong Zhou ◽  
Qi-Long Hu ◽  
Ya-Qi Li ◽  
...  

Two new isostructural complexes, namely, poly[aqua[μ3-2-(4-carboxyphenoxy)terephthalato-κ3 O 1:O 4:O 4′](1,10-phenanthroline-κ2 N,N′)cobalt(II)], [Co(C15H8O7)(C12H8N2)(H2O)] n or [Co(μ3-Hcpota)(phen)(H2O)] n , I, and poly[aqua[μ3-2-(4-carboxyphenoxy)terephthalato-κ3 O 1:O 4:O 4′](1,10-phenanthroline-κ2 N,N′)nickel(II)], [Ni(C15H8O7)(C12H8N2)(H2O)] n or [Ni(μ3-Hcpota)(phen)(H2O)] n , II, have been synthesized by solvothermal reactions. Complexes I and II were fully characterized by IR spectroscopy, elemental analyses, thermogravimetric analyses, and powder and single-crystal X-ray diffraction. They both present two-dimensional structures based on [M 2(μ-COO)2]2+ (M = CoII or NiII) dinuclear metal units with a fes topology and a vertex symbol (4·82). Interestingly, the positions of the two dimeric metal motifs and the two partially deprotonated Hcpota2− ligands reproduce regular flying butterfly arrangements flipped upside down and sharing wings in the ab plane. Magnetic studies indicate antiferromagnetic interactions (J = −5.21 cm−1 for I and −11.53 cm−1 for II) in the dimeric units, with Co...Co and Ni...Ni distances of 4.397 (1) and 4.358 (1) Å, respectively, that are related to double syn–anti carboxylate bridges.


2000 ◽  
Vol 55 (9) ◽  
pp. 796-802 ◽  
Author(s):  
H. Kara ◽  
Y. Elerman ◽  
K. Prout

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


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