Hydrothermal syntheses, structural characterizations, and magnetic properties of five MOFs assembled from C2-symmetric ligand of 1,3-di(2′,4′-dicarboxylphenyl)benzene with various coordination modes

RSC Advances ◽  
2015 ◽  
Vol 5 (50) ◽  
pp. 39854-39863 ◽  
Author(s):  
Liming Fan ◽  
Weiliu Fan ◽  
Bin Li ◽  
Xian Zhao ◽  
Xiutang Zhang
Keyword(s):  
Magnetic Properties ◽  
Crystal Structures ◽  
Structural Features ◽  
Paddle Wheel ◽  
Coordination Modes ◽  
Hydrothermal Syntheses ◽  
Structural Characterizations

Five new complexes with appealing structural features from 0D paddle wheel {Cu2(COO)4} SBUs to 3D frameworks were reported to better understand the synthon selectivity in multifunctional crystal structures.

Triazolate-based 3D frameworks and a 2D layer with centrosymmetric CuII7, CuII5, CuII4 clusters and tunable interlayer/interchain compactness: hydrothermal syntheses, crystal structures and magnetic properties

2015 ◽  
Vol 44 (12) ◽  
pp. 5826-5836 ◽  
Author(s):  
Yuan-Yuan Zhang ◽  
Hong Zhao ◽  
En-Cui Yang ◽  
Zhong-Yi Liu ◽  
Qiu Shang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystal Structures ◽  
Ground States ◽  
Hydrothermal Syntheses

A 2D layer and three 3D frameworks with different interchain/interlayer compactness and spin ground-states were reported.

scholarly journals Diversity of Coordination Modes in a Flexible Ditopic Ligand Containing 2-Pyridyl, Carbonyl and Hydrazone Functionalities: Mononuclear and Dinuclear Cobalt(III) Complexes, and Tetranuclear Copper(II) and Nickel(II) Clusters

2019 ◽  
Vol 5 (3) ◽  
pp. 39 ◽  
Author(s):  
Evangelos Pilichos ◽  
Evangelos Spanakis ◽  
Evangelia-Konstantina Maniaki ◽  
Catherine P. Raptopoulou ◽  
Vassilis Psycharis ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Metal Ion ◽  
Variable Temperature ◽  
Exchange Interactions ◽  
Structural Features ◽  
Coordination Modes ◽  
Susceptibility Data ◽  
Anionic Ligand ◽  
1H Nuclear Magnetic Resonance ◽  
Ditopic Ligand

Syntheses, crystal structures and characterization are reported for four new complexes [Cu4Br2(L)4]Br2 (1), [Ni4(NO3)2(L)4(H2O)](NO3)2 (2), [Co2(L)3](ClO4)3 (3) and [Co(L)2](ClO4) (4), where L− is the monoanion of the ditopic ligand N′-(1-(pyridin-2-yl)ethylidene)pyridine-2-carbohydrazide (LH) built on a picolinoyl hydrazone core fragment, and possessing a bidentate and a tridentate coordination pocket. The tetranuclear cation of 1·0.8H2O·MeOH is a strictly planar, rectangular [2 × 2] grid. Two 2.21011 L− ligands bridge adjacent CuII atoms on the short sides of the rectangle through their alkoxide oxygen atoms, and two 2.11111 ligands bridge adjacent CuII atoms on the long sides of the rectangle through their diazine groups; two metal ions are 5-coordinate and two are 6-coordinate. The tetranuclear cation of 2·0.2H2O·3EtOH is a square [2 × 2] grid. The two 6-coordinate NiII atoms of each side of the square are bridged by the alkoxide O atom of one 2.21011 L− ligand. The dinuclear cation of 3·0.8H2O·1.3MeOH contains two low-spin octahedral CoIII ions bridged by three 2.01111 L− ligands forming a pseudo triple helicate. In the mononuclear cation [Co(L)2]+ of complex 4, the low-spin octahedral CoIII center is coordinated by two tridentate chelating, meridional 1.10011 ligands. The crystal structures of the complexes are stabilized by a variety of π–π stacking and/or H-bonding interactions. Compounds 2, 3 and 4 are the first structurally characterized nickel and cobalt complexes of any form (neutral or anionic) of LH. The 2.01111 and 1.10011 coordination modes of L−, observed in the structures of complexes 3 and 4, have been crystallographically established for the first time in coordination complexes containing this anionic ligand. Variable-temperature, solid-state dc magnetic susceptibility and variable-field magnetization studies at 1.8 K were carried out on complexes 1 and 2. Antiferromagnetic metal ion···metal ion exchange interactions are present in both complexes. The study reveals that the cation of 1 can be considered as a practically isolated pair of strongly antiferromagnetically coupled (through the diazine group of L−) dinulear units. The susceptibility data for 2 were fit to a single-J model for an S = 1 cyclic tetramer. The values of the J parameters have been rationalized in terms of known magnetostructural correlations. Spectral data (infrared (IR), ultraviolet/visible (UV/VIS), 1H nuclear magnetic resonance (NMR) for the diamagnetic complexes) are also discussed in the light of the structural features of 1–4 and the coordination modes of the organic and inorganic ligands that are present in the complexes. The combined work demonstrates the ligating flexibility of L−, and its usefulness in the synthesis of complexes with interesting structures and properties.

Sign in / Sign up

Export Citation Format

Share Document