Investigation of N-H center dot center dot center dot O interactions in N-monosubstituted caproamide - Ether systems: FT-IR and FT-NIR spectroscopic study

This paper reports FT-IR and FT-NIR spectroscopic study of hydrogen bonding between N-mono-substituted caproamides and different ethers (diethyl ether and tetrahydrofuran) in carbon tetrachloride. With increase in ether concentration increase in intensity of red-shifted band, and decrease of intensity of monomer band has been observed. The MIR and NIR spectroscopic characteristics for N-H center dot center dot center dot O hydrogen bonded complexes and also the equilibrium constants for 1:1 complex formation are given. Further, influence of structural differences of ethers on hydrogen bonding was investigated using Taft equation. Good correlation between logarithm of formation constants and Taft steric and inductive factors has been obtained only for tetrahydrofuran in MIR range

FTIR investigation of solvent effects of N-methyl and N-tert-butyl benzamide

Infrared spectroscopy studies of N-methyl benzamide and N-tert-butyl benzamide in 12 organic solvents were undretaken to investigate solvent-solute interactions. The wavenumbers of carbonyl stretching vibration nu(C=O) in different solvents were correlated with the solvent acceptor number (AN), the linear solvation energy relationships (LSER), Catalan solvent parameters (SA, SB and SPP) and Buckingham equation. For both studied amides significant correlation of the position of the carbonyl band with empirical parameters was obtained. Based on obtained results it was assumed that the amide self-association and the steric effects are most important factors that determine position of carbonyl groups band in the IR spectra

Experimental and computational study of polycrystalline LiInO2 structure vibration properties

Polycrystalline LiInO2 was synthesized by the solid-state method and was characterized using combined experimental and computational methods. The results of experimental measurements were compared with the computational analysis of lattice vibrations based on DFT calculations. A good agreement between experimental and theoretical frequencies of LiInO2 structure vibration mode was obtained. © 2023, Publishing House of the Romanian Academy. All rights reserved

Polymeric Copper(II) Complexes with a Newly Synthesized Biphenyldicarboxylic Acid Schiff Base Ligand—Synthesis, Structural and Thermal Characterization

The newly synthesized biphenyldicarboxylic acid Schiff base and its complexes with Cu(II) were synthesized, and their spectroscopic and structural analysis was performed. The reaction of the ligand and copper(II) acetate in different solvents resulted in the formation of two solvatomorphic complexes, one with MeOH, and the other with DMF molecules, in the crystal lattice. The differences in the results of the thermal analysis could be explained by the different polarities of the solvents present. SC-XRD analysis revealed that the ligand is coordinated as a dianion, in a pentadentate manner, through two phenoxide oxygen atoms, two azomethine nitrogen atoms, and with the oxygen atom of one carboxylate functioning as a bridge that connects the monomeric units. The coordination polyhedron was described with several parameters obtained from different methods of calculation. The presence of different solvents in the crystal structure results in differences in the H-bond networks, and an overall different crystal packing of the structural units in the obtained complexes

Polymeric Copper(II) Complexes with a Newly Synthesized Biphenyldicarboxylic Acid Schiff Base Ligand—Synthesis, Structural and Thermal Characterization

The newly synthesized biphenyldicarboxylic acid Schiff base and its complexes with Cu(II) were synthesized, and their spectroscopic and structural analysis was performed. The reaction of the ligand and copper(II) acetate in different solvents resulted in the formation of two solvatomorphic complexes, one with MeOH, and the other with DMF molecules, in the crystal lattice. The differences in the results of the thermal analysis could be explained by the different polarities of the solvents present. SC-XRD analysis revealed that the ligand is coordinated as a dianion, in a pentadentate manner, through two phenoxide oxygen atoms, two azomethine nitrogen atoms, and with the oxygen atom of one carboxylate functioning as a bridge that connects the monomeric units. The coordination polyhedron was described with several parameters obtained from different methods of calculation. The presence of different solvents in the crystal structure results in differences in the H-bond networks, and an overall different crystal packing of the structural units in the obtained complexes

Synthesis, Characterization, and Impact of Water on the Stability of Postmodified Schiff Base Containing Metal–Organic Frameworks

In this study, the synthesis of a Schiff base containing metal–organic frameworks (MOFs) of the UiO-67 family has been investigated. MOFs featuring free amine groups were successfully synthesized under mild solvothermal conditions using 2-amino-[1,1′-biphenyl]-4,4′-dicarboxylic acid and 2,2′-diamino-[1,1′-biphenyl]-4,4′-dicarboxylic acid as bridging ligands, resulting in MOFs with amine groups covalently linked to the bridging ligands. Both types of functionalized MOFs were post-synthetically modified with 4-formylbenzonitrile that resulted in imine formation. All the obtained compounds were characterized by PXRD, TGA, DTA, BET, NMR, and FTIR spectroscopy, while stability in water was monitored with SEM, EDS, and UV–VIS spectroscopy

Synthesis, Characterization, and Impact of Water on the Stability of Postmodified Schiff Base Containing Metal–Organic Frameworks

In this study, the synthesis of a Schiff base containing metal–organic frameworks (MOFs) of the UiO-67 family has been investigated. MOFs featuring free amine groups were successfully synthesized under mild solvothermal conditions using 2-amino-[1,1′-biphenyl]-4,4′-dicarboxylic acid and 2,2′-diamino-[1,1′-biphenyl]-4,4′-dicarboxylic acid as bridging ligands, resulting in MOFs with amine groups covalently linked to the bridging ligands. Both types of functionalized MOFs were post-synthetically modified with 4-formylbenzonitrile that resulted in imine formation. All the obtained compounds were characterized by PXRD, TGA, DTA, BET, NMR, and FTIR spectroscopy, while stability in water was monitored with SEM, EDS, and UV–VIS spectroscopy