The synthesis and characterisation of coordination and hydrogen-bonded networks based on 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid

Abstract

. (2015). The synthesis and characterisation of coordination and hydrogen-bonded networks based on 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid. Dalton Transactions: an international journal of inorganic chemistry, 44 (19), 9269-9280.The synthesis and characterisation of coordination and hydrogen-bonded networks based on 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid AbstractThe synthesis, structural and thermal characterisation of a number of coordination complexes featuring the N,O-heteroditopic ligand 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoate, HL are reported. The reaction of H2L with cobalt(II) and nickel(II) nitrates at room temperature in basic DMF/H2O solution gave discrete mononuclear coordination complexes with the general formula {[M(HL)2(H2O)4]·2DMF} (M = Co (1), Ni (2)), whereas the reaction with zinc(II) nitrate gave [Zn(HL)2]∞, 3, a coordination polymer with distorted diamondoid topology and fourfold interpenetration. Coordination about the tetrahedral Zn(II) nodes in 3 are furnished by two pyrazolyl nitrogen atoms and two carboxylate oxygen atoms to give a mixed N2O2 donor set. The desolvation of 8 was followed by powder X-ray diffraction and single crystal X-ray diffraction which show desolvation induces the transition to a more closely packed structure while the coordination geometry about the copper ions and the network topology is retained. Powder X-ray diffraction and microanalysis were used to characterise the bulk purity of the coordination materials 1-6 and 8. The thermal characteristics of 1-2, 4-6 and 8 were studied by TG-DTA. This led to the curious observation of small exothermic events in networks 4, 6, and 8 that appear to be linked to their decomposition. In addition, the solid state structures of H2L and that of its protonated salt, H2L·HNO3, were also determined and revealed that H2L forms a 2-D hydrogen bonded polymer incorporating helical chains formed through N-HO and O-HN interactions, and that [H3L]NO3 forms a 1-D hydrogen-bonded polymer. The synthesis and characterisation of coordination and hydrogen-bonded networks based on 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid donor sets with trans-square planar geometry and is fourfold interpenetrated. The desolvation of 8 was followed by powder X-ray diffraction and single crystal X-ray diffraction which show desolvation induces the transition to a more closely packed structure while the coordination geometry about the copper ions and the network topology is retained. Powder X-ray diffraction and microanalysis were used to characterise the bulk purity of the coordination materials 1-6 and 8. The thermal characteristics of 1-2, 4-6 and 8 were studied by TG-DTA. This led to the curious observation of small exothermic events in networks 4, 6, and 8 that appear to be linked to their decomposition. In addition, the solid state structures of H 2 L and that of its protonated salt, H 2 L•HNO 3 , were also determined and revealed that H

A mixed‐valence copper(I/II) coordination polymer directed with a bifunctional soft‐hard pyrazolate−carboxylate ligand

“…General: Reagents were obtained from commercial sources and used as received without further purification: The synthesis of 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoic acid (H 2 mpba), was carried out according to the literature procedure. [14] Elemental analyses (CHN) were performed using a PerkinElmer 2400 series II elemental analyzer. IR-spectra were recorded on a Bruker FT-IR Tensor 37 spectrometer in the 4000-500 cm À 1 region with 2 cm À 1 resolution as KBr disks.…”

“…The partial reduction to Cu(I) was not necessarily expected as previous work with the H 2 mpba ligand and Cu(II) salts in DMF yielded Cu(II) coordination polymers. [4,14] Here, we report the synthesis and characterization of the 1D, coordination polymer [Cu II {Cu I 3 (Hmpba)(mpba) 2 }DMF] •~3DMF. S1a, Supporting Information).…”

Crystal structure, solvothermal synthesis, thermogravimetric studies and DFT calculations of a five-coordinate cobalt(II) compound based on the N,N-bis(2-hydroxyethyl)glycine anion

“…There are several coordination modes for the cobalt ion. The common mode is six-coordinate (Bryant et al, 2015;Artetxe et al, 2015), and only relatively few four-coordinate (Gupta et al, 2015) and five-coordinate (Lee et al, 2015) cobalt complexes have been recorded. Generally, five-coordinate compounds have two classical configurations, trigonal-bipyramidal and square-pyramidal, and the extent of each geometry each can be determined by the value (Addison et al, 1984).…”

Rare Supramolecular Assemblies of a Dicopper(II)‐tetracarboxylate Stabilized by (Methanol)6, Dimethyl Sulfoxide and 4,4′‐Azobipyridyl Bridges

“…Designed synthesis of inorganic‐organic hybrid materials with the desired topology by the help of supramolecular interactions (e. g. hydrogen bonding, π⋅⋅⋅π and van der Waals interactions) is gaining importance in the field of crystal engineering . It should be noted that only a few examples of Cu(II) paddle‐wheel complexes are reported in which axial and equatorial positions serve as the point of extension through intermolecular interaction ,.…”