Compounds with visible-light-induced photoluminescence are particularly attractive in acting as the emitting components of light-emitting diodes and fluorescent probes for biological applications. A new complex [Zn(NCS)_3(MQ)](MQ^+ = N-methyl-4,4?-bipyridinium) with an isolated molecular structure has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and solid-state photoluminescent determination. Crystal data: C_(14)H_(11)N_5S_3Zn, M_r = 410.83, monoclinic, space group P2_1/c, a = 8.809(5), b = 13.138(7), c = 15.580(9) ?, b = 104.433(10)°, V = 1746.2(17) ?~3, Z = 4, D–c = 1.563 g×cm^3, μ = 1.769 mm^(–1), F(000) = 832, the final R = 0.0376 and wR = 0.1243 for 2850 observed reflections with I > 2s(I). In the crystal structure, the zinc atom is tetrahedrally coordinated by one MQ+ ligand and three NCS– groups to yield a tetrahedral configuration. The bond length of Zn–NMQ is clearly shorter than those found in reported Zn(Ⅱ) complexes of 4,4?-bipy. The isolated units are joined by C–H···S interactions to generate a 2D hydrogen-bonding network. This compound displays visible light-induced photoluminescence, which originates from both intraligand charge-transfer of the MQ+ ligand and NCS~–→MQ^+ charge-transfer according to a density of states(DOS) calculation. Moreover, its emission band shows a clear blue shift compared with those of halide compounds.
Two novel Ag coordination polymers based on tetrazole-yl acylamide, Ag(NTAA) (1, H-NTAA = N-(1H-tetrazol-5-yl)acetamide) and Ag(NTPA) (2, H-NTPA = N-(1H-tetrazol- 5-yl)propionamide) have been synthesized under solvothermal conditions and characterized by single-crystal X-ray diffraction. Compound 1 features a 3-connected 4.82-fes network and compound 2 displays a ladder-like chain. The different structures between 1 and 2 are mainly related with the substituent groups oftetrazole-yl acylamide.
Copper complexes that can experience reversible heat-induced dehydration and rehydration in the solid state were rarely reported although thermochromic copper complexes have been widely reported, and their heat-induced magnetic properties have not been studied. We firstly observed the reversible thermochromic phenomena of the known copper(II) complex [Cu(bpy)(OOCCH3)2]n·xn H2O(x = 2.5 or 3; bpy = 4,4'-bipyridine) in the solid state, which is associated with the dehydration and rehydration processes, and found that heat-induced coloration clearly enhanced the magnetic susceptibility.
The title complex, [Co2(bibzim)(H2bibzim)4]·Co2(H2bibzim)2(Hbibzim)(HL)]2- 2H2O (1) (HEbibzim = 2,2'-bibenzimidazole, H5L = N,N-bis(phosphonomethyl)aminoacetic acid (HO2CCH2N(CH2PO3H2)2)), was synthesized with hydrothermal reactions. The compound crystallizes in triclinic, space group P1 with a = 13.71020(10), b = 14.9165(5), c = 20.9924(5) A, a = 86.344(9), β = 71.214(8), γ = 73.757(7)°, C162HI24Co6N46O18P4, Mr = 3478.52, V = 3900.55(16) A3, Z = 2, Dc = 1.482 g/cm3,μ(MoKa) = 0.747 mm^-1, F(000) = 1784, the final R = 0.0777 and wR = 0.2091 for 13598 observed reflections (I 〉 2σ(I)). X-ray diffraction analysis reveals that there are three crystallographically independent Co(II) atoms in the complex. The complex consists of binuclear coordination cation, binuclear coordination anion, as well as lattice water molecules, which further aggregate into a 3D framework via hydrogen bonding as well as π-π interactions.
Hydrothermal reactions of Na2MoO2·2H2O and NH4VO3(or V2O5) with appropriate reducing agents such as organic amines, NH2OH·HCl and Mo(CO)6 gave rise to the formation of a series of capped Keggin derivatives, [N(CH3)4]2Na3(NH4)2[(V^VO4)Mo^VI8V^IV4O36(V^IVO)2]·-13H2O(1), [NH4]7[(V^VO4)Mo^VI8V^IV4O36(V^IVO)2]·7H2O(2), [HN(CH2CH2)3NH][(PO4)Mo^V3Mo^VI9O36(V^IVO)2]·-3[N(CH2CH2)3N]·(en)·4.5H2O(3) and [HNH2OH][NH4]2[(V^VO4)Mo^VI8V^IV4O36(V^IVO)4]·24H2O(4). Single-crystal X-ray diffraction analysis revealed that the anions in 1-3 are two-capped Keggin derivatives with characteristic trans vanadium-oxygen caps, whereas the heteropoly anion in 4 is a tetra-capped α-Keggin derivative with characteristic vanadium-oxygen caps on the equatorial plane.