A noncentrosymmetric polyphosphate compound, KBa2（PO3）5, 1 was prepared and characterized. It features 1D [PO3]∞ chains of condensed [PO4]^（3-） tetrahedral units. The polycrystalline sample of 1 exhibits second harmonic generation（SHG） response, demonstrating that the activity of the title compound is about 0.6 times that of KDP that is comparable to the isostructural RbBa2（PO3）5（2） and KPb2（PO3）5（3）. Additionally, powder X-ray diffraction（PXRD）, thermal analysis, IR spectroscopy, UV-Vis-near-IR diffuse reflectance spectroscopy, and theoretical calculations have been also studied, and the structure and property comparison among this type of polyphosphates are summarized.
The site occupancies and thermoelectric properties of tin-based clathrates Cs8M4Sn44□2 （M = Zn, Cd, Hg） and CssSn44□2 were studied by the first principle calculations. We had provided an efficient way to probe the relationship between the crystalline structure and power factor. Detailed analyses indicated the p states of Sn at 16i and 24k sites together with the p states of M substitute contributed significantly to the maximum power factor, yet Cs atoms nearly did not. The dangling bonds of vacancies in Cs8Snn44□2 are also discussed. The power factors of p- and n-type CssMaSn42 and Cs8Sn44□2 at optimal temperature and carder concentration are predicted. Our results suggest that Cs8ZnaSn44□2 is a promising candidate at the 5.25 ×10^19 cm-3 hole carrier concentration as a high temperature thermoelectric material that is competitive to the state-of-art Ge-based clathrate thermoelectric materials.
Two novel coordination compounds,1[Zn4（L1）4（NO3）2（H2O）2]（NO3）2·2H2O and 2[Mn2（L2）2（DMF）（H2O）3]（ClO4）2·DMF（HL1 = N＇-[（1E）-pyridine-2-ylmethylidene]pyrazine-2-carbohydrazide,H2L2 = 2-hydroxy-3-methoxybenzaldehyde（pyrazin-2-ylcarbonyl）hydrazone）,based on the N-N bridged ligands were prepared and structurally characterized.Compound 1represents the[2＊2]molecular squares,in which both N atoms belonging to the N-N bridged ligands are connected to the Zn centers.The emission of compound 1 exhibits a blue shift,which can be assigned to strong electrostatic interaction between Zn^Ⅱ ions and the L1^-1.Compound 2represents a rare phenol-O bridged Mn2^Ⅱ complex.The magnetic investigation indicates weak antiferromagnetic interactions between the Mn^Ⅱ centers.
Temperature dependent assembly of two novel Cd coordination polymers with the phen and H2MIP ligands （phen = 1,10-phenanthrolion and H2MIP = 5-methyl-isophthalic acid）, formulated as Cd2（MIP）2（phen）2 （1） and Cd3（MIP）3（H2MIP）（phen）2 （2）. They have been structurally characterized by single-crystal X-ray diffraction, elemental analysis, FT-IR spectra and TGA. 1 crystallizes in the monoclinic space group P2/n, while 2 crystallizes in the triclinic space group P1. 1 shows a 2D （two-dimensional） plane and 2 shows a 1D （one-dimensional） chain. In addition, their solid-state luminescent properties have also been investigated.
A new 2Fe2 S complex[（2-C5H4N）N（μ-CH2S）2Fe2（CO）6]（1） related to the active site of[FeFe]-hydrogenase was obtained by treating（HS）2Fe2（CO）6 with（pyridin-2-ylazanediyl）dimethanol.Protonation occurred at the pyridine nitrogen atom when two equivalents of HBF4·OEt2acid were added to the toluene solution of 1,leading to the formation of[（2-C5H4NH）N（μ-CH2S）2Fe2（CO）6]·BF4·OEt2（1H~＋）,whose molecular structure was further established by singlecrystal X-ray analysis.Complex 1 crystallizes in the monoclinic system,space group P21/n with α=7.728（3）,b = 11.825（4）,c = 17.888（6） A,β= 92.968（5）°,while complex 1H~＋ crystallizes in the triclinic system,space group P1 with a = 7.672（4）,b = 10.382（5）,c = 16.480（10） A,α=106.575（13）,β= 93.18（3）,γ=104.262（17）°.
Two homochiral enantiomorphic 3D coordination polymers： （D-HAPA）2[Cd2Cs（D- HAPA）（m-BDC）4]＇（EtOH） （1D） and （L-HAPA）2[Cd2Cs（L-HAPA）（m-BDC）a]＇（EtOH） （1L） （APA = 2-amino-l-propanol, m-H2BDC = 1,3-benzenedicarboxylate）, have been assembled solvothermally respectively with the induction of enantiomorphic organic small molecules （D,L-APA）. 1L and 1I） crystallize in chiral space group P21 with Flack parameters of-0.012（13） and -0.07（3）, respectively, and have been characterized by satisfactory elemental analysis, FT-IR spectra, CD-spectra and single-crystal X-ray diffraction. They both exhibit sqp topological net, purple fluorescence and SHG activity.
A new zero-dimensional（0D） thioborate Ba_9B_3GaS_（15） has been discovered by conventional high-temperature solid-state reaction. The compound crystallizes in orthorhombic space group Pbca with a = 8.4759（8）,b = 22.266（2）,c = 31.426（3） ？,V = 5931（2） ？~3,Z = 8,Mr = 1819.11,Dc = 4.075 g/cm3,μ = 13.684 mm^（-1）,F（000） = 6320,S = 1.034,（Δρ）max = 5.039,（Δρ）min = –5.409 e/？~3,the final R = 0.0362 and w R = 0.1053 for 19243 observed reflections with I 〉 2σ（I）. The structure is constructed by discrete [BS_3]^（3–） trigonal planes and isolated [GaS_4]^（5–） tetrahedra with Ba^（2＋） and isolated S^（2–） filled among them. The UV-Vis-near-IR spectrum reveals a wide band gap of 3.15 eV that agrees with the electronic structure calculation.
In_4Se_3-based materials are noticeable n-type thermoelectric materials because of lead-free and intrinsically low lattice thermal conductivity,but the In4Se_3-δ crystals（with Se-deficiency,δ） suffer strong anisotropy and cleavage habit. Thus the researches on polycrystalline In_4Se_3-based materials are of great importance. Herein,we experimentally and theoretically investigated the thermoelectric properties of In_（4-x）Se_（2.95）Ag_x polycrystalline compounds. Ag occupying the intercalation or In4 site is energetically most favorable in light of the density functional theory calculation. The maximum solubility of Ag（x_m） is very low（xm 〈 0.03） and the experimental result indicates that the electrical transport behavior of In_（4-x）Se_（2.95）Ag_x compounds is not significantly optimized by Ag-dopant. Consequently,a maximum ZT of 0.92 at 723 K is obtained by In_（3.98）Se_（2.95）Ag_（0.02） compound that represents 15% enhancement over that of the un-doped one which benefits from the slightly enhanced power factor and the reduced total thermal conductivity.
A new mixed-valence cyanide-bridged complex, Br3Fe（p-NC）RuBr（dppm）2 （dppm = bis（diphenylphosphino）methane）, was obtained through the reaction between trans-（dppm）2C1- RuCN and FeBr3. Its crystal structure was characterized. Electronic absorption spectra indicate the existence of metal-to-metal charge transfer （MMCT） and this complex is Class II mixed valence complexes according to the classification of Robin and Day. Magnetic analysis shows it is paramagnetic.
Solvothermal reactions of Zn（NO3）2·6H20 with isophthalic acid in the presence of potassium nitrate lead to an acentric three-dimensional （3D） hereto-metallic inorganic-organic hybrid framework [ZnK2（m-BDC）ffH20）2]n （1, m-H2BDC = benzene-l,3-dicarboxylic acid）. The crystal was characterized by elemental analysis, IR spectroscopy, TGA and single-crystal X-ray diffraction analysis. Complex 1 is of orthogonal crystal system, acentric space group Cmc2j with a = 19.764（6）, b = 19.948（6）, c = 12.039（4） A, V = 4746（3） A3, Z = 4, C32H20019KaZn2, Mr = 995.66, Dc= 1.393 g/cm3, F（000） = 2000 andp = 1.426 mm-1. The final R = 0.0761 and wR = 0.1841. The crystal exhibits remarkable blue luminescence emissions with high quantum yield of 56.02% and displays modest powder SHG efficiency of about 0.7 times that produced by a potassium dihydrogen phosphate （KDP） powder. In addition, it also exhibits potential ferroelectric property.
