Related Experiment Video
Updated: May 28, 2025
Synthesis of Ligand-free CdS Nanoparticles within a Sulfur Copolymer Matrix
Published on: May 1, 2016
Syntheses and structures of two coordination polymers formed by Ni(cyclam)2+ cations and sulfate anions
Liudmyla V Tsymbal1, Irina L Andriichuk1, Lucian G Bahrin2
1L. V. Pisarzhevskii Institute of Physical Chemistry of the National Academy of Sciences of Ukraine, Prospekt Nauki 31, 03028, Kyiv, Ukraine.
Abstract:
The asymmetric units of catena-poly[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N 1,N 4,N 8,N 11)nickel(II)]-μ2-sulfato-κ2 O 3:O 4], [Ni(SO4)(C10H24N4)] (I), and catena-poly[[(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N 1,N 4,N 8,N 11)nickel(II)]-μ2-sul-fato-κ2 O 3:O 4] hemi[4,4',4'',4'''-(2,2',4,4',6,6'-hexa-methyl-[1,1'-biphen-yl]-3,3',5,5'-tetra-yl)tetra-benzoic acid] nona-hydrate], {[Ni(SO4)(C10H24N4)]2·C46H38O8·18H2O} (II), consist of two crystallographically unique centrosymmetric macrocyclic dications and a sulfate dianion. In II it includes additionally a mol-ecule of the undissociated acid (2,2',4,4',6,6'-hexa-meth-yl[1,1'-biphen-yl]-3,3',5,5'-tetra-yl)tetra-(benzoic acid) located on a crystallographic twofold axis and nine highly disordered water mol-ecules of crystallization. In both compounds, the metal ions are coordinated in the equatorial plane by the four secondary N atoms of the macrocyclic ligand, which adopts the most energetic-ally stable trans-III conformation. Two O atoms of the sulfate anions occupy the trans-axial positions resulting in a slightly tetra-gonally distorted trans-NiN4O2 octa-hedral coordination geometry. The crystals of both compounds are composed of parallel coordination polymeric chains running along the [101] and [100] directions in I and II, respectively. The distances between the neighboring metal ions in the chains are significantly different [6.5121 (6) Å in I and 6.0649 (3) Å in II] and this peculiarity is explained by the different spatial directivity of the Ni-O coordination bonds (different S-O-Ni angles). As a result of the C-H⋯O hydrogen bonds between the methyl-ene groups of the macrocyclic ligands and the non-coordinated O atoms of the sulfate anion, the coordination-polymeric chains in I are arranged in the two-dimensional layers oriented parallel to the (010) and (101) planes, the inter-section of which provides the three-dimensional coherence of the crystals. The three-dimensional supra-molecular structure of the crystals II is determined by the network of strong hydrogen bonds formed by the carb-oxy-lic acid and the non-coordinated O atoms of the sulfate anions.
Related Concept Videos
02:54Coordination Compounds and Nomenclature
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
02:42Valence Bond Theory
02:57Coordination Number and Geometry
02:51Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...