Based on cobalt, nickel and copper complexes of molecular magnetic materials Preparation and Properties

Title: Based on cobalt, nickel and copper complexes of molecular magnetic materials Preparation and Properties Author: Cui new surgery Degree-granting units: Northeast Normal University Keywords: molecular magnetic materials;; Magnetic - structure correlation;; complexes;; crystal structure;; acid ligand;; bipyridine ligand Abstract:
Molecular magnetic materials is not only a neodymium magnets new type of functional materials, and is involved in chemistry, physics, materials and life sciences pay
New cross-disciplinary field. It appeared to break with the traditional magnetic materials only from the 3d, 4f orbital electrons of inorganic metals and oxygen
The boundaries of objects, and absorbed organic matter density, flexibility, processability, biocompatibility, etc., so both have important
Academic sense, but also has special potential for application. However, these new materials is still in the exploratory stage, for the magnetic mechanism
Not yet accepted the explanation.
Paramagnetic molecular magnetic materials is usually one or more metal ions and organic ligands (and lattice water) group
Into, so the material properties depends on the metal center and ligand species and the formation of three-dimensional structure. In order to reveal the material properties and group
Into the nature and structure of the intrinsic relationship between the hydrothermal synthesis paper, were selected pyridine 2,6 - dicarboxylic acid ions (pdc2-)
And isophthalic acid ion (ip-) as a http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php bridging ligand or ligand skeleton will Co ~ (2 +), Ni ~ (2 +) and Cu ~ (2 +) ions linked into a variety of dimensions
Number of magnetic skeleton, 2,4 '- bipyridine (2,4'-bpy) ligand and its derivatives used to adjust for hanging skeleton, has been of 12
New complexes. Were studied (i) ligand skeleton and the same metal center, different suspension ligand complexes of the structure and magnetic properties of the film
Ring; (ii) ligand skeleton and hanging with the same body, the metal center (and the coordinated water molecules) changes resulting from complex changes in the structure and magnetic properties
Technology; (iii) frame the same ligand and metal centers, ligands of different suspension formed complexes with lattice water, the amount of water on the lattice with
The magnetic properties of compounds. While summing the product of the structural characteristics of synthetic and magnetic properties of the relationship between the new points for such compounds
The application of sub-magnetic materials to provide theoretical and experimental basis. Research include the following four parts:
1, so
Pyridine 2,6 - dicarboxylic acid ions (pdc ~ (2 -)) as the skeleton is the ligand bridging ligand, 2,4 '- bipyridine (2,4'-bpy) and
Its derivatives 5 - phenyl -2,4 '- bipyridine (5-ph-2, 4'-bpy) or 5 - (4 - bromo) - phenyl -2,4' - bipyridine (5 -
(4-Br)-ph-2, 4'-bpy) ligands for the suspension or the axial ligand under hydrothermal conditions with divalent cobalt or nickel ions reaction of four new
Complexes [Co (pdc) (2,4 '-bpy) _2 · H_2O] _n (1), [Co (pdc) (5-ph-2, 4'-bpy) _2 · H_2O] _n (2) ,
[Co (pdc) (5 - (4-Br-ph) -2,4 '-bpy) _2 · 2H_2O] _n (3) and [Ni (pdc) (5-ph-2, 4'-bpy) _2 *
H_2O] _n (4). Complexes 1-4 by trans-O-C-O carboxylic acid metal centers bridged antiferromagnetic interaction. In complex 1
, 2 and 4, there is a crystallographic independent metal ions, which are skeleton ligand pdc2? Ion bridging the metal to form a zigzag polymer
Chain, while in complex 3 has two crystallographically independent cobalt ions, through pdc2? The formation of two polymer bridged cobalt (Co1 and Co2) chain.
As the suspension introduced on the ligand phenyl substituents, making the two cobalt chains in the polymerization of cobalt chain than a more distorted, and the introduction of the suspension with the body
Bromophenyl obtained after 3 in the chain becomes twisted Co1, Co2 chain is not distorted. The results show that for complexes 1-3 run, CoII between
Antiferromagnetic interactions with the distorted structure of the polymer chains increases to 1> 3> 2 in the order weakened.
2, the pyridine-2 ,6
- Acid ion and water for the skeleton ligand, 2,4 '-bpy and its derivatives 5-ph-2, 4'-bpy and 5 - chloro-2,4' - bipyridine
(5-Cl-2, 4'-bpy) ligands for the suspension of divalent copper ions react with the preparation of three new complexes [Cu (pdc) (2,4 '-bpy)
(H_2O)] · 4H_2O (5), [Cu (pdc) (5-ph-bpy) (H_2O)] · 2H_2O (6) and Cu (pdc) (5-Cl-2,4 '-bpy)
(H_2O) (7). In compounds 5 and 6 there are different configurations of the lattice water clusters. Complexes 5 in class chair conformation of the eight water molecules together
(H_2O) 8 stacked along the a-axis with the formation of a water molecule, while complex 6 hexamer water into a highly ordered self-assembled comb-type water class
Chain. With different compounds 5 and 6, 7 there is no lattice water molecules, there is only one coordinated water molecule. Studies have shown that the anti-ferromagnetic phase between CuII
Interaction with the lattice water in order to increase the number of 7> 6> 5 order weakened.
3, two contain the same synthetic skeleton L1
And suspension L2 ligand complexes [Ni (L1) (L2) _2 · H_2O] n (8) and [Cu4 (L1) _4 (L2) _4] · 2H_2O (9) (L1 = pdc ~ (2
-), L2 = 5 - (4-Br)-ph-2, 4'-bpy), combined with [Co (L1) (L2) _2 · H_2O] _n (3) to discuss its structure
And magnetic change reasons. 8 and 3, twisted metal ions with octahedral geometry of six-coordinated geometry, through the bridging ligand pdc2
- L2 is connected to form a suspension with a one-dimensional polymer chain body, and in the complexes 9, five-coordinate metal ions to the distortion of a few square tapered
Any configuration with the L1 and L2 ligand, the formation of four Cu cluster. Found in the structure and magnetic properties of these compounds are metal and the corresponding coordination model dependent,
That is one-dimensional polymer 8 and 3, there are anti-ferromagnetic coupling, and in four Cu 9 cluster ferromagnetic coupling is found. Meanwhile, the density functional theory
(DFT) calculations show that the quad-core copper cluster 9 O-C-O bridges for passing between the ferromagnetic metal exchange.
4, selected phthalic acid ion
(Ip-) as the framework ligands, 2,4 '-bpy ligands for the suspension with different metal ions (cobalt, nickel and copper) reaction had three new complexes
{[Cu (ip) (2,4 '-bpy) 2] · H_2O} _n (10), {[Co (ip) (2,4'-bpy) _2] · H_2O} _n (11) and [Ni (ip) (2,4
'-Bpy) _2 (H_2O)] _n (12). X-ray crystallographic study showed that 10 and 11 metal ions are ip ~ (2 -) ions to form connections
Rings containing eight yuan and sixteen one-dimensional ring tape, and in the complexes of nickel ions through 12 ip ~ (2 -) ions and water molecules connected with eight
Ring ring and twenty-one-dimensional tape. Because the type of metal center and / or coordinated water molecules, complexes 11 M · · · M distances shorter than
Complexes 10 and 12 in the distance. Metal ions between the antiferromagnetic interaction of metal with metal tape to increase the distance to 11
> 10> 12 less. Degree Year: 2009