Synthesis, Characterization, and Magnetic Studies of Coordination Polymers with Co(II) and Mn(II) Ions (original) (raw)
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Polyhedron, 2007
(1), [Cd(3-ampy)(N 3 )Cl] n (2), and [Cd(DENA)Cl 2 (H 2 O)] n (3), (pydz = pyridazine or 1,2-diazine, 3-ampy = 3-aminopyridine, DENA = N,N-diethylnicotineamide) have been synthesized and characterized by spectral and structural methods and their network topologies analysed. Complex 1 crystallizes in monoclinic C-centred space group C2/m, the Zn(1) center is octahedrally coordinated; and simultaneously bridged by EO-azido, N,N 0 -pydz, and O,O 0 -sulphato ligands. The ZnN 4 O 2 -octahedra form a 1D anionic chain along b-axis. The Na(OH 2 ) 6 -octahedra have also common water molecules, thus also forming a 1D chain along b-axis. The cationic and anionic chains are connected via hydrogen bonds of type O-HÁ Á ÁO including lattice water molecules to form a supramolecular 3D network structure. In complex 2, the Cd(1) is six-coordinated by two EE-bridging azide groups, and two nitrogen atoms of bridging N,N 0 , 3-ampy ligand, and two bridging chloro ligands. The three different bridging ligands connect the distorted octahedra of the Cd(II) centres to form a 3D network structure with the topology of a square pyramidal net (4 3 AE 6 6 -sqp). The centrosymmetric Cd 2 Cl 2 -rings are planar and the NH 2 -of the 3-ampy groups forms additional hydrogen bonds of type N-HÁ Á ÁN to the adjacent azido groups. In complex 3, the octahedrally coordinated Cd(1) centres are occupied by alternating monodentate DENA ligand and a water molecule and the other four sites are occupied by four bridging chloro ligands. Thus the Cd 2 Cl 2 -rings form common edges to form 1D chains of Cd(II) octahedra along the b-axis of the monoclinic unit cell. 2D supramolecular sheets extended along the bc-planes of the unit cell are formed by the O-HÁ Á ÁO hydrogen bond. The IR spectra of the three complexes were measured and they confirm the X-ray structural data.
Two new coordination polymers containing the triangular [Mn3O(O2CR)6]0/+ units
Inorganica Chimica Acta, 2008
a b s t r a c t The preparation and crystal structures of two linear chain compounds of oxo-centered triangular Mn clusters are reported. {[Mn 4 O(O 2 CMe) 8 (py)] Á 2MeCN} 1 (1 Á 2MeCN) 1 was formed when a concentrated solution of [Mn 3 O(O 2 CMe) 6 (py) 3 ] Á py in MeCN was left undisturbed at room temperature for several weeks. The repeating unit of the chain polymer (1 Á 2MeCN) 1 consists of an oxo-centered trinuclear [Mn 3 O] 6+ unit linked to a Mn II center through l-and l 3 -O 2 CMe ligands. {[Mn 3 O(O 2 CPh) 7 (4,4 0 -bpy)] Á 3H 2 O} 1 (2 Á 3H 2 O) 1 was prepared by reductive aggregation of NBu n 4 MnO 4 in MeOH/benzoic acid in the presence of 4,4 0 -bipyridine. The structure consists of chains of [Mn 3 O(O 2 CPh) 7 (4,4 0 -bpy)] units. The one-dimensional chains are linked into 2D networks by p-stacking interactions between benzoate phenyl rings.
A Family of 3-D Coordination Polymers Composed of Mixed-Valence Mn6 Octahedra within Na4 Tetrahedra
Journal of Cluster Science, 2010
The combined use of 1,1,1-tris(hydroxymethyl)ethane (thmeH 3 ) and azides in Mn carboxylate chemistry has yielded a new family of decanuclear [Mn 6 Na 4 ; Et (2)) complexes consisting of mixed-valence Mn 2 II Mn 4 III units with a very rare [Mn 6 (l 6 -O)] 14? octahedral core contained within a tetrahedron of four Na I atoms. The [Mn 6 Na 4 ] units of 1 and 2 are connected via the Na atoms to neighboring units, giving 3-D supramolecular assemblies with large channel cavities. Variable-temperature, solid-state dc and ac magnetization studies carried out in the 1.8-300 K range reveal that the Mn 6 units of 1 and 2 are antiferromagnetically coupled to give S = 0 ground states for both complexes.
Polyhedron, 2013
Two new compounds [Mn(dca) 2 (dmdpy)] (1) and [Co(dca) 2 (dmdpy)] (2) (dca = dicyanamide and dmdpy = 5,5 0-dimethyl-2,2 0-dipyridine) were synthesized and characterized by single crystal X-ray diffraction, FTIR, thermal analysis and magnetic measurements. In both compounds, the dmdpy ligand adopts a bidentate chelating coordination mode while dca anions act as bidentate l 1,5 bridging ligand and the metal centers are involved in a distorted octahedral geometry. In compounds 1 and 2, dca ligands connect the metal sites giving rise to 1D and 2D coordination polymers, respectively. Weak antiferromagnetic interactions were observed between the metal centers in both compounds.
Polyhedron, 2014
The work in this report deals with seven compounds of composition {[Cu II (dmpn) 2 ] 3 [Fe III (CN) 6 ] 2 Á6H 2 O} n (1), {[Cu II (dmpn) 2 ] 3 [Co III (CN) 6 ] 2 Á6H 2 O} n (2), {[Cu II (dmpn) 2 ] 3 [Cr III (CN) 6 ] 2 Á4H 2 O} n (3), {[Cu II (dmpn)][Ni II (CN) 4 ]ÁH 2 O} n (4), [{Cu II (dmpn) 2 Cl}{Cu II (dmpn) 2 (H 2 O)}][Ag I (CN) 2 ]Cl 2 (5), [(Cu II (dmpn) 2 (dicyanamide) 2 ] (6) and [(Ni II (dmpn) 2 (dicyanamide) 2 ] (7), where dmpn = 2,2-dimethyl-1,3-diaminopropane. Syntheses, characterization and crystal structures of 1-7 along with variable-temperature (2-300 K) magnetic properties of 1 and 3 are described. Compounds 1-4 are cyanide-bridged two-dimensional coordination polymers. Twelve metal-membered ring is formed in 1-3, while both four and eight metal-membered rings are formed in 4. On the other hand, dicyanoargentate(I) in 5 is noncoordinated and dicyanamide in 6 and 7 behaves as monodentate terminal ligand. The coordination polymers in 1-4 and the discrete systems in 5-7 are self-assembled by hydrogen bonding interactions to generate overall three-dimensional supramolecular topologies. A novel structural aspect, two-dimensional network containing both four and eight metal-membered rings, has been observed in the copper(II)-tetracyanonickelate(II) compound 4. Magnetic studies reveal ferromagnetic interaction between Cu II and Cr III in 3. In addition, spin-orbit coupling of low-spin Fe III or weak antiferromagnetic interaction along with intermolecular antiferromagnetic interactions which exist between Cu II and Fe III are present in 1.
Inorganica Chimica Acta, 2000
Treatment of bis(hexafluoroacetylacetonato)diaquamanganese(II) [Mn(hfac) 2 (H 2 O) 2 ] with 4,4-bipyridyl gives cis-[Mn II (hfac) 2-(bipy)] (1), which forms zigzag 1-D chains. The bipyridyl ligands coordinate to the Mn cations adopting a cis geometry with an N Mn N angle of 90°. Treatment of bis(hexafluoroacetylacetonato)diaquacopper(II) [Cu(hfac) 2 (H 2 O) 2 ] with 1,3-dipyridylpropane gives trans-[Cu II (hfac) 2 (1,3-dipy)] (2), which forms 1-D chains that adopt a trans N Cu N angle of 180°. Treatment of [M(hfac) 2 (H 2 O) 2 ] (M=Co or Cu) with 4,4-bipyridyl-N,N%-dioxide gives trans-[Co II (hfac) 2 (4,4-bipy-N,N%-dioxide)] (3) and trans-[Cu II (hfac) 2 (4,4-bipy-N,N%-dioxide)] (4), respectively, which form isostructural linear chains with an O M O angle of 180°.
Inorganic Chemistry, 2010
The bridging of hexanuclear mixed-valent carboxylate coordination clusters of the type [Mn 6 O 2 (O 2 CR) 10 ] (R = CMe 3 ; CHMe 2) featuring a {Mn II 4 Mn III 2 (μ 4-O) 2 } core by geometrically rigid as well as flexible spacer ligands such as pyrazine (pyz), nicotinamide (na), or 1,2-bis(4-pyridyl)ethane (bpe) results exclusively in one-dimensional (1D) coordination polymers. The formation of {[Mn 6 O 2 (O 2 CCMe 3) 10 (Me 3 CCO 2 H)(EtOH)(na)] 3 EtOH 3 H 2 O} n (1), {[Mn 6 O 2 (O 2 CCHMe 2) 10 (pyz) 3 ] 3 H 2 O} n (2), and {[Mn 6 O 2 (O 2 CCHMe 2) 10 (Me 2 CHCO 2 H)(EtOH)(bpe)] 3 Me 2 CHCO 2 H} n (3) illustrates a surprising preference of the interlinked {Mn 6 } units toward 1D coordination chains. In the solid-state, the observed chain propagation axes are either colinear (1 and 3) or perpendicular (2), whereby crystal packing is further influenced by solvent molecules. Magnetic properties of these network compounds can be rationalized based on that the magnetism of discrete [Mn 6 O 2 (O 2 CR) 10 ]-type coordination clusters with all-antiferromagnetic intramolecular exchange and weak antiferromagnetic intercluster coupling in 1, 2, and 3 follows the expected exchange coupling strength of the employed spacer linkers.
Polyhedron, 2014
Five polymeric Mn(II) complexes with bridging carboxylato groups were prepared and structurally characterized. The bridging carboxylato ligand in double-chain coordination polymeric structures of [Mn(l-3-NO 2 bz) 2 (bipy)] n ÁnH 2 O, [Mn(l-3,5-(NO 2 ) 2 bz) 2 (bipy)] n , [Mn(l-5-(NO 2 )sal) 2 (bipy)] n , and [Mn(l-5-(NO 2 )sal) 2 (phen)] n , where 3-NO 2 bz À = 3-nitrobenzoate, 3,5-(NO 2 ) 2 bz À = 3,5-dinitrobenzoate, 5-(NO 2 )sal À = 5-nitrosalicylate, bipy = 2,2 0 -bipyridine and phen = 1,10-phenanthroline, exhibits the syn-anti bidentate bridging mode. The Mn(II) atom in the coordination polymer [Mn(l-4-NO 2 bz)(4-NO 2 bz)(phen)(H 2 O)] n , where 4-NO 2 bz = 3-nitrobenzoate, is coordinated by terminal carboxylato groups in the syn monodentate mode but two Mn(II) atoms are connected with bridging 4-nitrobenzoate ligands in the anti-anti bidentate bridging mode. The magnetic susceptibility and magnetization data confirm that weak exchange interactions of an antiferromagnetic nature apply in these complexes.
A new highly anisotropic coordination hetero-bimetallic polymer [Mn III (Schiff-base)] 3 [Re IV (CN) 7 ] was synthesized and characterized structurally and magnetically. The single crystal X-ray analysis has revealed that this is the first framework among the complexes composed of homoleptic cyanometallate and Mn III complex of the tetradentate Schiff base ligand. A formation of 3D assembly is possible due to both the pentagonal bipyrimidal geometry of the cyanome-tallate unit and suitable size of constituents: [Re(CN) 7 ] 3− and [Mn III (acacen)] + , where acacen = N,N′-ethylenebis-(acetylacetoneiminato). The powder and crystal magnetic studies show that the compound undergoes an antiferromag-netic ordering of a complicated character below Neel temperature of 13 K, and exhibits a metamagnetic behavior and strong magnetic anisotropy similar to those observed in related 3D Mn II −[Mo(CN) 7 ] 4− systems. Unusual magnetic properties of [Mn III (acacen)] 3 [Re IV (CN) 7 ] (1) originate from an interplay of Re−Mn anisotropic spin coupling and ZFS effect of Mn III ions with a noncollinear orientation of the local magnetic axes in the cyano-bridged 3D network. A theoretical model of anisotropic spin coupling between orbitally degenerate [Re IV (CN) 7 ] 3− complexes and Mn III ions is developed, and specific microscopic mechanisms of highly anisotropic spin coupling in Re IV −CN−Mn III linkages in complex 1 are analyzed in detail.