[The Hydrothermal Synthesis, Structure and Spectroscopy Study on (H2dap)6H[V12B16O54(OH)4] · 12H2O (dap = 1, 2-diaminopropane)].
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.