Supramolecular structures of metal complexes containing barbiturate and 1,2-bis(4-pyridyl)-ethane

Crystal architectures of copper and zinc metal complexes containing 2-thiophenepropionate and 1,2-bis(4-pyridyl)ethane building blocks

“…Due to the complexity of the synthesized three-dimensional arrangement it has been performed a topological analysis of the crystal system; the description of this polymer has been made by the TOPOS program package [33], where the metal ion (Zn 2+ ) i s con si dered as th e n et n ode, an d th e coordination polymer is constituted by a 3-connected uninodal net that can be described with short Schläfli symbols 6 3 . Figure 3 Table 3, as well as the tentative vibrational assignment based on similar chemical systems [20,[35][36][37]. It is important to note that all spectra are very similar and in agreement with the crystal data.…”

“…Figure 5 shows that such bands appear shifted to higher wavenumbers when this ligand is coordinated with the metal ion [12,20]. In this work the band at 1596 cm -1 , assigned to n(CC)/n(CN) for the free ligand, can be observed for all the complex a shift to higher wavenumbers, probably caused by the strengthening of the chemical bond, mainly due to the participation of non-bonding electrons in the chemical bond.…”

“…It is broadly used in coordination chemistry as a bidentate bridging ligand, as a terminal ligand or as a host molecule [20], and can also be further involved in hydrogen bonding and/or π-stacking interactions [21]. This kind of molecule has been used to assemble the inorganic building layers to provide porous coordination polymers with variable properties [22] and supramolecular motifs, including ladder (1D), brick wall (2D), molecular bi-layer (2D) and frame (3D), based on T-shaped coordination [23].…”

Thiobarbiturate and barbiturate salts of pefloxacin drug: Growth, structure, thermal stability and IR-spectra

“…The very broad bands in the 3600-3400 cm −1 can be assigned to stretching modes of NH and OH for PefH2 + , Htba -and Hba -ions. In the region of stretching vibrations С=О in IR spectra of Hba -ion the band with the highest frequency lies at 1688 cm −1 [34]. In alkaline and alkali earth metals (M) thiobarbiturate bond MO is weak and predominantly ion-dipole in nature, therefore one can assume that stretching vibrations C=O which were found in IR spectra of these compounds can be attributed to uncoordinated Htba -ions.…”

“…In the analysis of the IR spectra used the results of these studies [32][33][34][35]. The IR spectra of 2 ( Figure 4S, curve 1) and 3 ( Figure 4S, curve 2) markedly differ from spectra of initial reagents (PefH, H2tba or H2ba), which indicates the obtainment of new compounds.…”