Synthesis, Structure and Physical Properties of A Novel 2D Cd(II) Coordination Polymer Involving 4-Thiopyridine Based on in situ Formation from 4,4'-Dithiodipyridine

Experimental

General. All reagents and solvents were commercial available and used without further purification. Infrared spectrum was recorded on a VECTOR 22 spectrometer, over the range 4000–400 cm−1, using KBr pellet. Elemental analysis data (C, H, N) were obtained using a Perkin-Elmer model 240C automatic instrument. The luminescence spectrum was obtained with a Fluoro Max-P spectrophotometer on solid crystalline samples anchored to quartz microscope slides. Thermogravimetric analysis (TGA) was performed under flowing N2 on a Perkin-Elmer Pyris 1 TGA analyzer with a heating rate of 20 ℃ min−1 up to 900 ℃.

Synthesis of [Cd2(odpa)(4-pytH)2·H2O]n (1). A mixture of Cd(NO3)2·6H2O (0.0346 g, 0.100 mmol), H4odpa (0.0346 g, 0.100 mmol) and 4-dtdp (0.0441 g, 0.200 mmol) in H2O (10 mL) was sealed in a 16 mL Teflon-lined stainless steel container and heated at 180 ℃ for 72 h. After cooling to room temperature, colorless block crystals were collected by filtration and washed by water and ethanol several times. (yield 41.2%, based on H4odpa). Elemental analysis for C26H18Cd2N2O10S2 (Mr = 807.38): C 38.68%, N 3.47%, H 2.25%; found: C 38.79%, N 3.48%, H 2.26%. IR (KBr pellets)/cm−1: 3539 (m), 3199 (m), 3119 (m), 2356 (w), 1680 (m), 1577 (s), 1526 (s), 1420 (s), 1379 (s), 1259 (s), 1171 (s), 1142 (m), 987 (s), 855 (s), 722 (s), 476 (w).

Structural Determination and Refinement. Crystallographic diffraction data for complex 1 was recorded on a Siemens (Bruker) SMART CCD diffractometer using monochromated Mo–Kα radiation (λ = 0.71073 Å) at 291 K. Absorption correction was applied using multi-scan technique. The structure was solved by direct method using the program SHELXL–97 and refined by full–matrix least–squares technique on F2 with SHELXL–97.18 All non-hydrogen atoms were located in difference Fourier maps and refined with anisotropic temperature parameters. The H atom of N(pyridine) atom was located in a difference Fourier map. All other H atoms were refined isotropically, with the isotropic vibration parameters related to the non–H atom to which they are bonded. A summary of the structural determination and refinement for the title complex is listed in Table 1 and the selected bond distances and angles are shown in Table 2.

Table 1.

Table 2.Symmetry transformations used to generate equivalent atoms: i −x, y, −z+1/2, ii x, −y, z−1/2, iii −x, −y, −z+1.