Hydrothermal Synthesis and Crystal Structure of a Novel Binuclear Cd(Ⅱ) Coordination Polymer Based on 1,2-Benzenedicarboxylate and Imidazole

The hydrothermal reaction of Cd(OAc)2·H2O with 1,2-benzenedicarboxylate(1,2-BDC),imidazole and H2O resulted in the formation of a binuclear polymeric Cd(Ⅱ) complex {[Cd2(1,2-BDC)2(Im)4]·(H2O)}n which was then characterized by elemental analyses and single-crystal X-ray diffraction analysis.The crystal is of monoclinic system,space group P21/c with a = 14.6455(3),b = 9.3530(2),c = 23.7838(5) ,β = 106.6290(10)°,C112H104Cd8N32O36,Mr = 3373.47,V = 3121.64(11) 3,Dc = 1.795 g/cm3,F(000) = 1672,μ = 1.428 cm-1 and Z = 1.The final R = 0.0316 and wR = 0.0687 for 5045 reflections with I > 2σ(I).In the title complex,the two Cd(Ⅱ) ions are in different coordination environments with distorted octahedral and pengonal bipyramidal geometries,respectively.Two Cd polyhedra are linked together through one μ2-η1:η1 and one μ2-η1:η2 carboxylate groups from different 1,2-BDC ligands,giving rise to a binuclear Cd(Ⅱ) cluster,and such clusters are connected by bridged 1,2-BDC ligands to form a 2-D structure along the c axis.The inter-and intermolecular hydrogen bonds further connect the 2-D structures into a 3-D supramolecular network.     

Structure and Properties of a New Rare-earth Borate LiSrY_2（BO_3）_3

The structure of LiSrY2(BO3)3 has been solved by single-crystal X-ray diffraction analysis at 298 and 113 K on different diffractometers.It crystallizes in trigonal with space group P-3m1(No.164).The cell parameters at room temperature are as follows:a = 10.3345(9),c = 6.4049(11) ,V = 592.41(13) 3,Z = 3,Mr = 448.81,F(000) = 618,μ = 21.327 mm-1 and Dc = 3.774 g/cm3.The crystal structure consists of gear-like [BY6O33] groups which are linked together by corner-sharing to form a two-dimensional layer parallel to the ab plane.These layers are connected one after another by sharing oxygen atoms with B(2) atoms along the c direction to construct a three-dimensional framework.Li and Sr atoms just occupy the cavities formed by oxygen atoms.In addition,the vibrational spectroscopy of LiSrY2(BO3)3 and photoluminescence properties of the Eu3+ doped LiSrY2(BO3)3 were also studied.     

Hydrothermal Synthesis and Crystal Structure of a Novel Selenite-chloride：[Cd4（SeO3）2Cl4（H2O）]n with a Three-dimensional Framework

A novel three-dimensional(3-D) compound [Cd4(SeO3)2Cl4(H2O)]n(1) was prepared from a hydrothermal reaction and structurally characterized.Compound 1 crystallizes in the space group Fmmm of the orthorhombic system with eight formula units in a cell:a = 15.5165(4),b = 17.5090(9),c = 7.3318(5) ,V = 1991.9(2) 3,Cd4Cl4H2O7Se2,Mr = 863.38,Dc = 5.758 g/cm3,S = 1.075,μ(MoKα) = 16.820 mm-1,F(000) = 3088,R = 0.0427 and wR = 0.1220.Compound 1 features a 3-D structure with the cadmium atoms having two different coordination environments,i.e.,six-and eight-coordination geometries.Two different chain-like structures of cadmium-oxo polyhedra are interconnect to each other to give a 2-D layer of [Cd4(SeO3)2(H2O)]n4n+.Between the [Cd4(SeO3)2(H2O)]n4n+ layers is a novel chloride layer.A 3-D framework is constructed from these [Cd4(SeO3)2(H2O)]n4n+ layers linked by the chloride layers.     

A Novel 3D Supramolecular Framework of Poly[(5-(oxidediphenylphosphino)isophthalate)zinc(Ⅱ)]: Syntheses and Structure

A novel metal-organic framework, namely [Zn(C20H13O5P)]n(1), has been hydrothermally synthesized through the reaction of 5-(oxidediphenylphosphino)isophthalic acid(H2L) with Zn(Ⅱ) salt. The title compound crystallizes in monoclinic, space group P21/c with a = 11.0966(10), b = 14.5651(14), c = 14.7311(15), β = 130.022(6)o, C20H13O5 PZn, Mr = 429.64, V = 1823.3(3) 3, Dc = 1.565 g/cm3, F(000) = 872, μ = 1.463 mm-1, S = 1.054 and Z = 4. The final R = 0.0270 and wR = 0.0739 for 2769 observed reflections with I 2σ(I). In the title complex, the Zn2(CO2)2 binuclear clusters are linked by L2- ligands to result in a pillared layer structure in the bc plane, which is a(4,4)-net composed of helical chains with opposite chirality by sharing Zn2(CO2)2 units. Adjacent layers are further associated together through Zn–O bonds involving the metal center and the oxygen atom of P=O group to achieve a 3D architecture, in which one-dimensional quadrangled channel displays the interweaving of two pairs of coaxial double-helical chains with opposite chirality. The luminescence property and thermogravimetric analysis of the title complex were investigated.     

CRYSTAL STRUCTURE OF GdCl_3(DIMETHOXYETHANK)_2

<正> C8H2oCl3GdO4,Mr=443.80,monoclinic, space group P21/c, a=11.442 (3),b= 8.849(2), c= 15.575(5)A,β=104.8l(2)° ,V=1521.9(7)A3,Z= 4, DC = 1.94 g/cm3,λ(MoKα) =0.71069A,F(000)=860. The structure was solved by Patterson and Fourier techniques and refined by least-squares nethod to a final conventional lvalue of 0.051 (Rw=0.054). The central ion Gd(III) is bonded to three chlorine atoms and four oxygen atoms froa two dimethoxye-thane molecules to form a distorted pentagonal bipyramid. The Qd-Cl distances are in the range of 2.460-2.628A (average 2.571A). The Gd-O distances are in the range of 2.408-2.493A (average 2.458A).     

Synthesis and Crystal Structure of a Cadmium（Ⅱ） Coordination Polymer：[Cd_2Cl_4（bpme）]_n·n（2H_2O）

A novel coordination polymer, [Cd2Cl4(bpme)]n·n(H2O) (1, bpme=2,5-bis(be-nzoimidazol-2-yl)pyrazine), has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal of the complex belongs to the triclinic system, space group P , with a=7.0737(9), b=8.7886(11), c=9.4561(12) , α=105.3580(10), β=94.981(2), γ=96.879(2)°, V=558.46(12) 3, Mr=714.97, Z=1, F(000)=346, Dc=2.126 g/cm3, μ=2.412 mm-1, T=296(2) K, S=1.057, R=0.0533 and wR=0.1480. According to the structural analysis, the Cd(Ⅱ) ion adopts a slightly distorted six-coordinated octahedral geometry. The Cd(Ⅱ) atoms are bridged by four Cl atoms along the a direction, forming infinite straight chains which are further constructed to generate 2D network layer structures through the μ4-N bpme ligand in the b direction, and such 2D network layer structures finally form a novel three-dimensional infinite supramolecular framework through weak π-π stacking between two network layers and hydrogen bonds.     

Syntheses,Crystal Structures,and Antimicrobial Activities of 3-Bromo-N＇-（2- chloro-5-nitrobenzylidene）benzohydrazide and 3-Bromo-N＇-（4-nitrobenzylidene）benzohydrazide

Two new hydrazone compounds, 3-bromo-N'-(2-chloro-5-nitrobenzylidene)-ben- zohydrazide 1 and 3-bromo-N'-(4-nitrobenzylidene)benzohydrazide 2, have been synthesized and characterized by elemental analysis, IR spectra, 1H NMR, and single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P21/c with a=7.7924(10), b=24.490(3), c=7.8989(9) , β=94.987(6)°, V=1501.7(3) 3, Z=4, R=0.0345 and wR=0.0739. Compound 2 crystallizes in monoclinic, space group P21/c with a=7.4099(11), b=24.868(4), c=8.3255(12) , β=112.796(8)°, V=1414.3(4) 3, Z=4, R=0.0744 and wR=0.1912. Both compounds display E configurations with respect to the C=N double bonds. In the crystal structure of 1, molecules are linked through N-H…N and N-H…O hydrogen bonds, forming chains running along the c axis. In the crystal structure of 2, molecules are linked through N-H…O hydrogen bonds, forming chains running along the c axis. The preliminary antimicrobial activities were studied.     

Synthesis, structure and bonding of the hypoelectronic cluster compound Sr3Tl5

The Sr3Tl5 phase was prepared by high temperature synthesis techniques through reaction of the high purity elements in the welded Nb tubes.The structure established through X-ray structural analysis shows the compound is a good hypoelectronic trielide example of the Pu3Pd5 structural type in which skeletal electron count is lower than in a traditional Zintl phase(Cmcm,Z = 4;a = 10.604(2) ,b = 8.675(2) ,and c = 10.985(2) ;V = 1010.5(3) 3).The strontium size and the compound’s polarity appear responsible for this thallium phase crystallization in the Pu3Pd5 family type rather than the isoelectronic Sr3In5 version.A first-principle electronic structure calculation(LMTO) demonstrates that the strontium atoms participate substantially in Sr-Tl bonding in the structure.     

Layered Lanthanum Complex with 3-Nitrophthalic Acid Assembled via Hydrogen Bonds-Synthesis, Structure and Characterization of [LaL(HL)(H_2O)_3]_2·2H_2O (H_2L=3-NO_2C_6H_3(CO_2H)_2)

A new dinuclear centrosymmetric complex [LaL(HL)(H2O)3]2·2H2O (H2L = 3-nitro- phthalic acid, NPA) was synthesized in water/ethanol solution and characterized by X-ray diffraction, IR spectrum and TGA-DTA. The complex crystallizes in triclinic system, space group P1 with a = 8.1549(16), b = 8.8856(18), c = 15.277(3) , α = 100.93(3), β = 90.81(3), γ = 104.56(3)°, V = 1049.8(4) 3, Z = 1, μ = 2.125 mm-1, Dc = 1.994 g/cm3, R = 0.0259 and wR = 0.0679. Two 3-nitrophthalates(2-) coordinate with the La3+ ions in a bridging mode, and two monohydrogen- 3-nitrophthates(1-) and three waters in terminal ways, respectively. Each La3+ ion is nine- coordinated to exhibit a distorted tricapped trigonal prism coordination polyhedron. Both the coordinated and crystal waters are involved in the inter- and intramolecular hydrogen bonds. The dinuclear units are linked into a 2D network structure in the ab plane via intermolecular hydrogen bonds along the axes a and b. Two crystal waters fill each rhombic pore of the network. The networks are further packed along the c axis forming a layered supramolecular structure through the C–H…O weak forces between the adjacent sheets. TGA analysis shows the complex undergoes the loss of waters of crystallization and coordination and the decomposition of ligands sequentially.     

‘Whole-molecule Disorder’ Refinement of 4-Tricyanovinyl-N,N-diethylaniline

The molecule of 4-tricyanovinyl-N,N-diethylaniline is disordered about an axis that is close to the axis passing through the 1,4-carbon atoms. The disorder is a 1:1 type of disorder that involves only part of the molecule as the diethylamino substitutent and the three nitrogen atoms of the tricyanovinyl substituent are ordered. The treatment of the nearly ‘whole-molecule disorder’ by employing a small number of restraints is described. Crystal data: C15H14N4, triclinic, P , a = 7.1996(5), b = 7.7232(5), c = 12.4171(8) , α = 99.350(1), β = 94.647(1), γ = 103.312(1)o and V = 657.90(8) 3 at –173 K.     

新型三维开放骨架稀土硫酸盐[Ln4(H2O)4(SO4)10](C4N2H12)4(H2O)4(Ln=Gd,Eu)的合成、结构及荧光性质

以哌嗪为模板剂,在水-乙醇混合溶剂体系中溶剂热合成了两个具有三维开放骨架结构的稀土硫酸盐[Ln4(H2O)4(SO4)10](C4N2H12)4(H2O)4（Ln = Gd,化合物1和Eu,化合物2）,并对其进行了结构表征、热重以及荧光光谱分析. 单晶结构解析表明,化合物1和2属于同构异质,均结晶于单斜晶系,P21/c空间群,化合物1,a = 19.691(3) ?,b = 19.249(3) ?,c = 13.186(2) ?,β = 92.33(0)o,V = 4993.5(1) ?3, Z =4. 化合物2,a = 19.7233(8) ?,b = 19.2791(8) ?,c = 13.2095(5) ?,β = 92.329(1)o,V = 5018.7(3) ?3, Z =4. 两个化合物在ab平面上由SO4,GdO8和GdO9多面体共边或共角交错连接形成含有八元环和十六元环的二维层状结构,该二维层沿c方向平行排列,相邻层通过SO4四面体相连形成具有孔道的三维开放骨架结构,其孔道之中包含平衡骨架负电荷的质子化哌嗪分子. 化合物2的固体荧光光谱分析显示其在397nm激发波长下,表现出典型的Eu3+发光性质.       

Syntheses and Crystal Structures of Two Gd（Ⅲ） Hydrogen Supramolecules Based on p-Sulfonatothiacalix[4]arene

Two novel polymeric complexes, [Gd（HsTCAS）（H2O）7]·4H2O 1 and [Gd（HsTCAS） （CH3COCH3）（H2O）6]·6H2O 2 （H4TCAS = p-sulfonatothiacalix[4]arene）, have been synthesized and characterized by single-crystal X-ray diffraction analyses. Complex 1 crystallizes in monoclinic, space group C2/m with a = 20.2308（12）, b = 19.0894（10）, c = 12.2448（7）A, β = 101.847（3）°, V = 4628.1（5）A^3, C24H43GdO27S8, Mr = 1169.25, Z = 4, Dc = 1.690 g/cm^3, F（000） = 2380,μ = 1.879 mm^-1, the final R = 0.0404 and wR = 0.1038 for 5127 observed reflections with I 〉 2σ（I）. Complex 2 is pseudo-isostructural with complex 1.     

Synthesis and structure of Ag(6)[(UO(2))(3)O(MoO(4))(5)]: a novel sheet of triuranyl clusters and MoO(4) tetrahedra

The new uranyl molybdate Ag(6)[(UO(2))(3)O(MoO(4))(5)] (1) with an unprecedented uranyl molybdate sheet has been synthesized at 650 degrees C. The structure (monoclinic, C2/c, a = 16.4508(14) A, b = 11.3236(14) A, c = 12.4718(13) A, beta = 100.014(4)(o), V = 2337.4(4) A(3), Z = 4) contains [(UO(2))(3)O(MoO(4))(5)] sheets composed of triuranyl [(UO(2))(3)O] clusters that are connected by MoO(4) tetrahedra. The topology of the uranyl molybdate sheet in 1 represents a major departure from sheets observed in other uranyl compounds. Of the approximately 120 known inorganic uranyl compounds containing sheets of polyhedra, 1 is the only structure that contains trimers of uranyl pentagonal bipyramids that are connected only by the sharing of vertexes with other polyhedra. The sheets are parallel to (001) and are linked by Ag cations.     

Structure of GdMg（BO2）5 Crystal

1 INTRODUCTION With the development of diode-pumped solid-sta- te lasers, the research to find more efficient materials for these lasers is gaining more importance. The luminescent materials host LnMgB5O10 may become potential solid-state laser materials[1, 2]. Nd3 -doped GdMg(BO2)5 as a potential diode-pumped laser crystal has been grown in our lab and characterized by a very strong absorption at near 808 nm and intense emission. Although the previous work repor- ted LaMg(BO2)5 with…     

New lanthanide silicates based on anionic silicate chain, layer, and framework prepared under high-temperature and high-pressure conditions

Three new lanthanide silicates K(1.25)Gd(1.25)Si(2.5)O(7.5) (denoted as GdSiO-CJ7), Cs(3)TbSi(8)O(19)·2H(2)O (denoted as TbSiO-CJ8), and Cs(3)DySi(6)O(15) (denoted as DySiO-CJ9) were synthesized by using a high-temperature and high-pressure hydrothermal method. Their structures determined by single-crystal X-ray diffraction revealed anionic silicate chain, layer and framework, which are further connected with LnO(n) polyhedra to form novel lanthanide silicate frameworks. The structure of GdSiO-CJ7 consists of unbranched silicate chains [Si(5)O(15)](10-) extending along the b axis, which are linked together by edge-sharing linked GdO(6) and GdO(8) chains along the c axis to form a 3-D framework with two types of 10-ring channels along the [010] and [001] directions, respectively. The structure of TbSiO-CJ8 consists of double 4,8-net sheets [Si(8)O(19)](6-) built up from SiO(4) tetrahedra, which are linked together via TbO(6) octahedra to form a 3-D framework with 8-ring channels along the [100] and [010] directions. The structure of DySiO-CJ9 is based on a 3-D silicate framework [Si(6)O(15)](6-) with 6-rings, where DyO(6) octahedra are located between two adjacent 6-rings and connected with six Si atoms via O atoms. The photoluminescence photoluminescence properties of TbSiO-CJ8 and EuSiO-CJ8 were investigated.     

One-dimensional array of two- and three-center cation-cation bonds in the structure of Li4[(UO2)10O10(Mo2O8)

Dark-red crystals of the new compound Li(4)[(UO(2))(10)O10(Mo(2)O(8))] (1) have been obtained by high-temperature solid-state reactions. The structure of 1 (monoclinic, P2(1)/c, a = 7.9426(4) A, b = 19.9895(9) A, c = 10.0796(5) A, beta = 90.575(2) degrees, V = 1600.24(13) A(3), Z = 4) consists of a framework of U and Mo polyhedra with Li+ cations in the channels. The framework contains seven-polyhedra-wide uranium oxide tapes interlinked by dimers of edge-sharing [4 + 1]-distorted MoO(5) polyhedra. The U-O tapes are parallel to the a axis, and their planes are oriented parallel to (021) and (02) so that they are cross-linked within the framework. The core of the tapes consists of unprecedented one-dimensional arrays of cation-cation-bonded uranyl ions. The arrays are constructed from eight-membered cycles with uranyl ions linked through two- and three-center cation-cation interactions.     

Synthesis, characterization, and structure-property relationships in two new polar oxides: Zn2(MoO4)(SeO3) and Zn2(MoO4)(TeO3)

Two new noncentrosymmetric (NCS) polar oxide materials, Zn(2)(MoO(4))(AO(3)) (A = Se(4+) or Te(4+)), have been synthesized by hydrothermal and solid-state techniques. Their crystal structures have been determined, and characterization of their functional properties (second-harmonic generation, piezoelectricity, and polarization) has been performed. The isostructural materials exhibit a three-dimensional network consisting of ZnO(4), ZnO(6), MoO(4), and AO(3) polyhedra that share edges and corners. Powder second-harmonic generation (SHG) measurements using 1064 nm radiation indicate the materials exhibit moderate SHG efficiencies of 100 × and 80 × α-SiO(2) for Zn(2)(MoO(4))(SeO(3)) and Zn(2)(MoO(4))(TeO(3)), respectively. Particle size vs SHG efficiency measurements indicate the materials are type 1 non-phase-matchable. Converse piezoelectric measurements resulted in d(33) values of ～14 and ～30 pm/V for Zn(2)(MoO(4))(SeO(3)) and Zn(2)(MoO(4))(TeO(3)), respectively, whereas pyroelectric measurements revealed coefficients of -0.31 and -0.64 μC/m(2) K at 55 °C for Zn(2)(MoO(4))(SeO(3)) and Zn(2)(MoO(4))(TeO(3)), respectively. Frequency-dependent polarization measurements confirmed that all of the materials are nonferroelectric; that is, the macroscopic polarization is not reversible, or "switchable". Infrared, UV-vis, thermogravimetric, and differential thermal analysis measurements were also performed. First-principles density functional theory (DFT) electronic structure calculations were also done. Crystal data: Zn(2)(MoO(4))(SeO(3)), monoclinic, space group P2(1) (No. 4), a = 5.1809(4) ?, b = 8.3238(7) ?, c = 7.1541(6) ?, β = 99.413(1)°, V = 305.2(1) ?(3), Z = 2; Zn(2)(MoO(4))(TeO(3)), monoclinic, space group P2(1) (No. 4), a = 5.178(4) ?, b = 8.409(6) ?, c = 7.241(5) ?, β = 99.351(8)°, V = 311.1(4) ?(3), Z = 2.     

Ligand influences on copper molybdate networks: the structures and magnetism of [Cu(3,4'-bpy)MoO(4)], [Cu(3,3'-bpy)(0.5)MoO(4)], and [Cu(4,4'-bpy)(0.5)MoO(4)].1.5H(2)O

The reactions of a Cu(II) salt, MoO(3), and the appropriate bipyridine ligand yield a series of bimetallic oxides, [Cu(3,4'-bpy)MoO(4)] (1), [Cu(3,3'-bpy)(0.5)MoO(4)] (2), and [Cu(4,4'-bpy)(0.5)MoO(4)].1.5H(2)O (3.1.5H(2)O). The structures of 1-3 exhibit three-dimensional covalent frameworks, constructed from bimetallic oxide layers tethered by the dipodal organoimine ligands. However, the [CuMoO(4)] networks are quite distinct. For structure 1, the layer consists of corner-sharing [MoO(4)] tetrehedra and [CuN(2)O(3)] square pyramids, while the layer of 2 is constructed from [MoO(4)] tetrehedra and binuclear [Cu(2)O(6)N(2)] units of edge-sharing copper square pyramids. The oxide substructure of 3 consists of [MoO(4)] tetrahedra corner-sharing with tetranuclear clusters of edge-sharing [CuO(5)N] octahedra. Crystal data: C(10)H(8)N(2)O(4)CuMo (1), orthorhombic Pbca, a = 12.4823(6) A, b = 9.1699(4) A, c = 19.5647(9) A, V = 2239.4(1) A(3), Z = 8; C(5)H(4)NO(4)CuMo (2), triclinic P, a = 5.439(1) A, b = 6.814(1) A, c = 10.727(2) A, alpha = 73.909(4)(o), beta = 78.839(4)(o); gamma = 70.389(4)(o); V = 357.6(1) A(3), Z = 2; C(10)H(8)N(2)O(8)Cu(2)Mo(2).3H(2)O 3.1.5H(2)O, triclinic P, a = 7.4273(7) A, b = 9.2314(8) A, c = 13.880(1) A, alpha = 71.411(2)(o), beta = 88.528(2)(o), gamma = 73.650(2)(o), V = 863.4(1) A(3), Z = 2. The magnetic properties of 1-3 arise solely from the presence of the Cu(II) sites, but reflect the structural differences within the bimetallic oxide layers. Compound 1 exhibits magnetic behavior consistent with ferromagnetic chains which couple antiferromagnetically at low temperature. Compound 2 exhibits strong antiferromagnetic dimeric interactions, with the magnetic susceptibility data consistent with the Bleaney-Bowers equation. Similarly, the magnetic susceptibility of 3 is dominated by antiferromagnetic interactions, which may be modeled as a linear S = 1/2 Heisenberg tetramer.     

Na(2/7)Gd(4/7)MoO4: a modulated scheelite-type structure and conductivity properties

Scheelite-type compounds with the general formula (A1,A2)(n)[(B1,B2)O(4)](m) (2/3 ≤ n/m ≤ 3/2) are the subject of large interest owing to their stability, relatively simple preparation, and optical properties. The creation of cation vacancies (□) in the scheelite-type framework and the ordering of A cations and vacancies can be a new factor in controlling the scheelite-type structure and properties. For a long time, cation-deficient Nd(3+):M(2/7)Gd(4/7)□(1/7)MoO(4) (M = Li, Na) compounds were considered as potential lasers with diode pumping. They have a defect scheelite-type 3D structure (space group I4(1)/a) with a random distribution of Li(+)(Na(+)), Gd(3+), and vacancies in the crystal. A Na(2/7)Gd(4/7)MoO(4) single crystal with scheelite-type structure has been grown by the Czochralski method. Transmission electron microscopy revealed that Na(2/7)Gd(4/7)MoO(4) has a (3 + 2)D incommensurately modulated structure. The (3 + 2)D incommensurately modulated scheelite-type cation-deficient structure of Na(2/7)Gd(4/7)MoO(4) [super space group I4 (α-β0,βα0)00] has been solved from single-crystal diffraction data. The solution of the (3 + 2)D incommensurately modulated structure revealed the partially disordered distribution of vacancies and Na and Gd cations. High-temperature conductivity measurements performed along the [100] and [001] orientation of the single crystal revealed that the conductivity of Na(2/7)Gd(4/7)MoO(4) at T = 973 K equals σ = 1.13 × 10(-5) Ω(-1) cm(-1).