Synthesis and Crystal Structure of a Two-dimensional Sil-ver(Ⅰ)-lron(Ⅲ) Heteronuclear Coordination Polymer: {[Ag_4Fe-2(SCN)_(12)(H_2O)_2][(inaH)_2(H_2O)_2]}_n

摘要

The 2-D heteronuclear coordination polymer {[Ag_4Fe-2(SCN)_(12)(H_2O)_2][(inaH)_2(H_2O)_2]}_n (1) (inaH is the abbreviation of protonated isonicotinic acid) with chemical formula C_(24)H_(20)Ag_4Fe_2N_(14)O_8S_(12) has been synthesized and characterized by single crystal X-ray diffraction, elemental analysis and IR spectroscopy. The Ag_2S_2 rings connect two kinds of octahedral geometries of Fe(Ⅲ) ions, [Fe(NCS)_6]~(3-) and [Fe(H_2O)_2(NCS)_4]~- units with bridging thiocyanate ions leading to 2-D [Ag_4Fe_2(SCN)_(12)(H_2O)_2]~(2-) anion framework. Four kinds of rings including the unprecedented thirty-two membered Ag_4Fe_4(SCN)_8 rings share corners or edges in the 2-D anion layer structure. All thiocyanates coordinate to the metal ions according to the HSAB principle with N atoms binding to the Fe(Ⅲ) ions and with S atoms binding to Ag(Ⅰ) ions. Pronoated ina cations stabilize the layer structure as counter ions and hydrogen bonds were formed within the pronoated ina cations dimer and between the dimers and the lattice waters. Crystal data: M_r= 1560.44, triclinic, P 1 , a=0.76082(1) nm, b=0.9234 nm, c= 1.85611(4) nm, α= 103.0170(10)°,β= 93.7780(10)°,γ=97.4080(10)°, V= 1.25385(3) nm~3, Z=l, μ(Mo Kα)=2.650 mm~(-1), D_c=2.067 g·cm~(-3), F(000)=758, R_1=0.0412, wR_2=0.1003.