Magnetic Properties and Crystal Structure of a Dinuclear Iron(III) Complex

2001 ◽  
Vol 56 (9) ◽  
pp. 897-900 ◽  
Author(s):  
A. Elmali ◽  
Y. Elerman ◽  
I. Svoboda

Abstract [FeL(MeOH)Cl]2 (L = N-(5-methylphenyl)-3-methoxysalicylaldimine) was synthesized and its crystal structure determined, [C30H26Cl2Fe2N2O6], triclinic, space group P1̄, a = 7.481(2), b = 9.436(2), c = 10.961(2) Å, α= 69.790(10), β= 82.440(10), γ= 83.690(10)°, V=718.1(3) Å3 , Z = 1. Two identical [FeLCl] fragments, related by an inversion centre, are connected by two bridging O atoms to form a binuclear unit. The iron(III) centers are separated by 3.196(2) Å and weakly antiferromagnetically coupled (J = -10.4(1) cm-1), which follows from temperature-dependent magnetic susceptibility measurements in the range 5.1 to 275.6 K. The magnetic moment at 275.6 K is ca. 7.02 B. M., but 0.99 B. M. at 5.1 K. The magnetic susceptibility is at a maximum near 80 K and decreases rapidly as the temperature is lowered to liquid helium temperature.

2003 ◽  
Vol 58 (5) ◽  
pp. 433-437 ◽  
Author(s):  
A. Elmali ◽  
Y. Elerman ◽  
C. T. Zeyrek ◽  
I. Svoboda

[Fe(L)Cl]2 (L = N-(4-methylphenyl)-3-methoxy-salicylaldimimine) was synthesized and its crystal structure determined. [C30H26Cl2Fe2N2O6], triclinic, space group P 1̄ , a = 9.278(2), b = 9.4050(10), c = 10.489(2) Å , α = 64.43(2), β = 74.540(10), γ = 62.40(2)° , V = 729.1(2) Å 3, Z = 1. Two identical [Fe(L)Cl] fragments, related by an inversion center, are connected by two bridging O atoms to form a binuclear unit. The iron(III) centers are separated by 3.196(2) Å and weakly antiferromagnetically coupled (J = -10.1(1) cm-1), as derived from temperature-dependent magnetic susceptibility measurements in the range 5.1-283.5 K.


1994 ◽  
Vol 49 (9) ◽  
pp. 1239-1242 ◽  
Author(s):  
Ayhan Elmali ◽  
Yalcin Elerman ◽  
Ingrid Svoboda ◽  
Hartmut Fuess ◽  
Klaus Griesar ◽  
...  

[FeL(MeOH)Cl]2 (L = N-(2-hydroxyphenyl)salicylaldimine) was synthesized and its crystal structure determined, [C27H20N 2O5Cl2Fe2], monoclinic, space group P21/c, a = 9.528(1), b = 7.684(1), c = 18.365(2) Å, β = 109.83(1)°, V = 1264.8 Å3, Z = 2. Two identical [FeL(MeOH)Cl] fragments, related by an inversion centre, are combined by the two bridging O atoms, to form a binuclear unit. The iron(III) centers are separated by 3.163(2) Å and weakly antiferromagnetically coupled (J = -8 .0 (1 ) cm-1), which follows from temperature - dependent magnetic susceptibility measurements in the range 4.2 to 288 K. The effective magnetic moment per iron(III) is μeff = 7.4 μB at 288 K


2001 ◽  
Vol 56 (10) ◽  
pp. 970-974 ◽  
Author(s):  
Y. Elerman ◽  
A. Elmali

[Cu2L(prz)] (prz = 3,5-dimethylpyrazole and L = 1,3-bis(5-bromo-2-hydroxybenzylidene)- propan-2-ol) was synthesized and its crystal structure determined. It crystallizes in the orthorhombic space group Pbca with a = 14.160(9), b = 15.109(4), c = 21.298(5) Å, V = 4557(1) A3, Z = 8 . Two copper(II) ions are in a square-planar coordination. The metal coordination sphere is four-coordinate, with a planar N2O2 donor set. The dihedral angle between the two coordination planes is 12.14(7)°. The copper(II) centers are separated by 3.365(1) Å and antiferromagnetically coupled (J = -214.3 cm-1), which follows from temperature-dependent magnetic susceptibility measurements in the temperature range 4.6 to 310 K. The Cu-O-Cu angle is 125.9(1)° in the super-exchange pathway. The magnetic moment at 310 K is ca. 1.76 B.M. and 0.13 B.M. at 4.6 K.


2000 ◽  
Vol 55 (7) ◽  
pp. 561-566 ◽  
Author(s):  
E. Kavlakoglu ◽  
A. Elmali ◽  
Y. Elerman ◽  
H. Fuess

[Cu2(L)(O2CMe)] · H2O (L = 1,3-Bis(2-Hydroxy-1-napthylideneamino)propan-2-ol) was synthesized and its crystal structure determined. (C27H23N2O5Cu2).H2O , monoclinic, space group P21/c, a = 11.795(3), b = 17.988(5), c = 12.005(6) Å, β = 109.99(3)°, V = 2393(2) Å3, Z = 4. Two copper(II) ions in a square-planar coordination are bridged by alkoxide and acetate oxygen atoms to form a dinuclear unit. The metal coordination sphere is four-coordinate, planar with an NO3 donor set. The dihedral angle between the two coordination planes is 6.34(9)°. The copper(II) centers are separated by 3.492(2) Å and weakly antiferromagnetically coupled (-2J = 163.6 cm-1 ), which follows from temperature-dependent magnetic susceptibility measurements in the temperature range 4.6 to 310 K. The Cu-O-Cu angle is 133.5(1)° in the super-exchange pathway. The weak antiferromagnetic coupling of the complex is interpreted in terms of countercomplementary effects of the different bridging ligands which participate in the super-exchange interaction. The magnetic moment at 310 K is ca. 2.7 B. M., but 0.2 B. M. at 4.6 K. The magnetic susceptibility is at a maximum near 140 K and decreases rapidly as the temperature is lowered to liquid helium temperature.


1998 ◽  
Vol 53 (11) ◽  
pp. 1281-1284 ◽  
Author(s):  
Manas Kumar Saha ◽  
Sutapa Sen ◽  
Parimal Kundu ◽  
Tarakranjan Gupta ◽  
Volker Gramlich ◽  
...  

[LCu{μ-(OH)2(C2O2)}CuL](ClO4)2, (HL = N,N-dimethyl N-propylsalicylald-imine) was synthesised and its crystal structure was determined. C26H36CI2Cu2N4O14, triclinic space group P1̅ with a = 9.288(9), b = 10.016(11), c = 10.09(2) Å and a = 101.05(11), β = 108.22(10), γ = 110.22(10)°, V = 787(2) Å3, Z = 2. Two copper(II) ions in a distorted square-planar coordination are bridged by an oxalic acid molecule to form dinuclear units. The copper(II) centres are separated by 5.2 Å and antiferromagnetically coupled (J = -478 cm-1), which follows from temperature-dependent magnetic susceptibility measurements in the range 12 to 300 K.


2002 ◽  
Vol 57 (10) ◽  
pp. 1129-1132 ◽  
Author(s):  
A. Elmali ◽  
Y. Elerman ◽  
I. Svoboda

The mixed-ligand dinuclear complex (2,2'-dipyridyl)-(2-acetylphenolato)copper(II) perchlorate was synthesized and its crystal structures determined. The structure consists of a dimeric unit involving a planar Cu2O2 group. The coordination sphere of the Cu atom can be described as an alongated octahedron where the basal plane is formed by the two N atoms of the 2,2'-dipyridyl molecule and the two O atoms of the acetophenon anion. Two apical Cu - O contacts complete the 4+2 coordination of the Cu atoms. They correspond to one of the O atoms of the perchlorate anion and to the O atom of the second unit. Magnetic susceptibility data obey the Curie-Weiss law with θ = -8.1(2) K. The decreasing of the effective magnetic moment from 1.94(8) μB at 300 K to 1.86(8) μB at 70 K and the negative Weiss constant indicate weak antiferromagnetic interactions between the two copper atoms in the dimeric units.


2011 ◽  
Vol 66 (11) ◽  
pp. 1097-1100 ◽  
Author(s):  
Larysa Shlyk ◽  
Rainer Niewa

Single crystals of the new barium hollandite Ba1.3Co1.3Ti6.7O16 were obtained from a BaCl2 flux (I2/m, Z = 1, a = 9.9470(4), b = 2.9714(2), c = 10.2260(5) Å , β = 90.906(2)◦). In the crystal structure piles of Ba atoms are situated within a framework of edge- and vertex-sharing octahedra (Co,Ti)O6. The composition was deduced from microprobe analyses, structure refinements and charge balance arguments in agreement with the observed magnetic properties. The temperature dependence of the magnetic susceptibility χ(T) of Ba1.3Co1.3Ti6.7O16 single crystals reveals paramagnetism down to 2 K. The value of the Co magnetic moment deduced from the Curie-Weiss law agrees well with the theoretical value of the high-spin state spin-only moment of μeff = 3.87 μB for Co2+ (S = 3/2)


1996 ◽  
Vol 51 (8) ◽  
pp. 1132-1136 ◽  
Author(s):  
Yalcin Elerman ◽  
Mehmet Kabak ◽  
Ingrid Svoboda ◽  
Hartmut Fuess ◽  
Klaus Griesar ◽  
...  

[Methylamino-(N,N′-1,3-propyl-disalicylaldiminato)-Ni(II)-bis-(N-methylsalicylaldiminato)- Ni(II)] was synthesized from the condensation of N,N′-1,3-propyl-disalicylaldimine, salicylaldehyde, methylaminohydrochloride, NaOH and Ni(CH3COO)2·H2O, and its crystal structure determined. [C34H37N5O4Ni2], orthorhombic, space group Pbca, a = 12.330( 1), b = 24.967(2), c = 20.616(2)Å, Z = 8. The dinuclear complex contains two octahedrally coordinated nickel atoms which are linked via three oxygen atoms with an average (Ni-O-Ni) angle of 87.2( 1)° and a Ni···Ni distance of 2.884(1)Å. The coordination is completed by three nitrogen atoms. The nickel(II) centers are ferromagnetically coupled (J = 11.5 cm-1) as derived from temperature-dependent magnetic susceptibility measurements in the range 5 - 280 K.


1995 ◽  
Vol 50 (11) ◽  
pp. 1587-1590 ◽  
Author(s):  
Yalcin Elerman ◽  
Mehmet Kabak ◽  
Ingrid Svoboda ◽  
Hartmut Fuess ◽  
Klaus Griesar ◽  
...  

The tetracupferronato-bis(μ-methoxy)-diiron(III) complex has been synthesized in acetonitrile and its crystal structure determined. C26H26N8O10Fe2, monoclinic, space group C2/c, a =18.425(3), b = 12.999(2), c = 15.046(3) Å, β = 124.66(2)°,V = 2964(1) Å3, Z = 4, wR(2) = 0.097 from 1491 reflections (F2). Two iron(III) atoms are at special positions in six-fold coordination, bridged by O with a Fe-O-Fe angle of 102.4(1)° and a distance between two iron(III) centers of 3.075(1) Å. Temperature-dependent magnetic susceptibility measurements reveal a antiferromagnetic exchange interaction (J = -14 cm-1) between the iron(III) centers.


2005 ◽  
Vol 60 (9) ◽  
pp. 940-944 ◽  
Author(s):  
C. T. Zeyrek ◽  
A. Elmali ◽  
Y. Elerman

A new dinuclear iron(III) derivative Fe2L(OCH3)Cl2 (L = 1,3-bis[N-(5-chloro-2-hydroxybenzylidene)- 2-aminoethyl]-2-(5-chloro-2-hydroxyphenyl)imidazolidine) has been synthesized, it crystal structure determined and magnetically characterized. The two iron(III) ions are asymmetrically bridged by a phenoxo and a methoxo group and separated by 3.150(2)Å . The magnetic susceptibility of the complex was measured over the range 5 - 349.3 K and the observed data were successfully simulated by the equation based on the spin-Hamiltonian operator , indicating very weak antiferromagnetic coupling between the iron ions with J = −11.3 cm−1. The magnetic and structural parameters of the compound and the nature of the magnetic super-exchange interaction are discussed and compared with data of similar dinuclear iron(III) complexes.


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