A polyoxovanadium borate (H2 dap)6H[V12B16O54(OH)4] · 12H2O (dap=1,2-diaminopropane) with novel structure was hydrothermally synthesized and characterized by the single crystal X-ray diffraction. It crystallizes in triclinic system with space group Piand unit cell parameters a=19.027(4), b=16.142(3) Å, c=26.679(5) Å, α=90°, β=101.06(3)°, γ=90°, V=8042(3) Å3, Z=4, Dc=1.962 g · cm(-3), μ=1.456 mm(-1), F(000)=4776, the final R1=0.0626, wR2=0.1927, S=1.003,for 7635 observed reflections with I>2σ(I). It is showed that the compound 1 is composed of V12B16 clusters unit and dap which is as a counter ion, and a two-dimensional layered structure is obtained by the effect of hydrogen bonding between the cluster units and dap, and between the layers via strong hydrogen bonds to form a three-dimensional supramolecular structure. The compound 1 were also characterized by IR, two-dimensional infrared (2D IR) correlation spectroscopy with magnetic and thermal perturbation, UV/Vis DRS spectra. The relationship between the structure and spectroscopy properties was discussed. The IR spectrum showed that the antisymmetric stretching vibration absorption peak νas (V-Oμ) and symmetric stretching vibration absorption peaks νs (V-Oμ) appeared at 775 and 683 cm(-1) respectively, whereas the vibration absorption peak in ν(B-O) of BO3 and the vibration absorption peak in ν(B-O) of BO4 appeared at 1350 and 1050 cm(-1) respectively. The response of the stretching vibrations of B-O and V-O was detected in the 2D IR correlation spectra with magentic perturbation. In addition, the response of the stretching vibrations of B-OH, B-O and V-O-V was detected in the 2D IR correlation spectra with thermal perturbation.
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Int J Pharm
December 2024
Center for Science of Imperatriz, Federal University of Maranhão - UFMA, 65900-410, Imperatriz, MA, Brazil. Electronic address:
This study reports the synthesis and the experimental-theoretical characterization of a new coamorphous system consisting of ethionamide (ETH) and mandelic acid (MND) as a coformer. The solid dispersion was synthesized using the slow solvent evaporation method in an ethanolic medium. The structural, vibrational, and thermal properties of the system were characterized.
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Felix-Bloch-Institut für Festkörperphysik, Universität Leipzig, Linnéstraße 5, 04103, Leipzig, Germany.
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Department of Chemistry, KTH Royal Institute of Technology, Teknikringen 29, SE-100 44 Stockholm, Sweden. Electronic address:
Nano-FTIR spectroscopy is a technique where atomic force microscopy (AFM) and infrared (IR) spectroscopy are combined to obtain chemical information with a lateral resolution of some tens of nm. It has been used to study numerous solid surfaces and recently also liquids including water have been examined by separating the liquid from the AFM tip by a thin lid. However, although the water stretching vibrations are significantly more intense than the bending vibration in conventional IR spectroscopy, only the bending vibration has been observed in nano-FTIR spectroscopy so far.
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College of Control Science & Engineering, China University of Petroleum (East China), Qingdao 266580, PR China.
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Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle-upon-Tyne NE1 8QH, United Kingdom.
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