Related Experiment Video
Updated: Oct 3, 2026

Experimental Approaches for the Synthesis of Low-Valent Metal-Organic Frameworks from Multitopic Phosphine Linkers
Published on: May 12, 2023
Supramolecular structures of cadmium(II) coordination polymers: a new class of ligands formed by linking tripodal
D L Reger1, T D Wright, R F Semeniuc
1Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208, USA.
Abstract:
The new ligands C(6)H(4)[CH(2)OCH(2)C(pz)(3)](2) (pz = pyrazolyl ring), 1 (ortho), 2 (meta), and 3 (para), that can potentially bond two or more metal centers were obtained in a single step from the reaction of the appropriate dibromoxylene, 2 equiv of tris-2,2,2-(1-pyrazolyl)ethanol, and excess NaH. Although the arrangement of the tris(pyrazolyl)methane units in the solid-state structures of 1 and 3 are similar, the orientation of these groups with respect to the phenyl ring are different, with 1 showing a twisted structure and 3 a stepped structure. The reaction of [Cd(2)(THF)(5)][BF(4)](4) with the appropriate ligand yields each of the three coordination polymers of the formula [C(6)H(4)[CH(2)OCH(2)C(pz)(3)](2)Cd](BF(4))(2)](n), 4 (ortho), 5 (meta), and 6 (para). In the solid-state structures of all three each tris(pyrazolyl)methane unit is tridentate, with each ligand bonded to two different cadmium(II) atoms, forming a coordination polymer containing 6-coordinate, pseudooctahedral cadmium(II) centers. Polymers 4 and 5 form wavelike chains whereas 6 is arranged in a stepped structure similar to the free ligand. The different connecting patterns of each ligand lead to very different supramolecular structures, structures organized by the BF(4)(-) groups through weak C-H...F hydrogen bonds. Crystallographic information: 1 is monoclinic, P2(1)/n, a = 16.3157(13) A, b = 8.5880(6) A, c = 21.9227(17) A, alpha = gamma = 90 degrees, beta = 100.134(2) degrees, Z = 4; 3 is monoclinic, P2(1)/n, a = 9.1965(9) A, b = 12.9185(12) A, c = 12.7306(12) A, alpha = gamma = 90 degrees, beta = 104.099(2) degrees, Z = 2; 4 is triclinic, P1, a = 10.7877(19) A, b = 12.582(2) A, c = 15.409(3) A, alpha =103.860(4) degrees, beta = 94.123(4) degrees, gamma = 92.573(4) degrees, Z = 2; 6 is monoclinic, C2/c, a = 23.023(3) A, b = 12.2588(14) A, c = 18.119(2) A, alpha = gamma = 90 degrees, beta = 121.281(2) degrees, Z = 4.
Related Concept Videos
Metal-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...
Coordination Number and Geometry
Valence Bond Theory
Coordination Compounds and Nomenclature
Structural 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 be...
Ladder Diagrams: Complexation Equilibria
The formation constant, K1, for the formation of Cd(NH3)2+ complex from cadmium and ammonia is 3.55 × 102. Log K1 (i.e. pNH3) is 2.55, and...

