Orthorhombic Space Group Pbam Research Articles

From Cs[C2N3] to Cs3[C6N9] – a thermal and structural investigation

Abstract Cesium dicyanamide Cs[C2N3] (≡ Cs[N(CN)2] or Cs[dca]) was obtained by a metathesis reaction in form of transparent colorless platelets. The results of single-crystal X-ray structure measurements and refinements (C2/c, Z = 8) with the monoclinic cell parameters a = 932.31(8), b = 1274.67(9), c = 824.94(7) pm, β = 110.803(3)° at −70 °C and a = 939.59(7), b = 1281.58(8), c = 827.57(6) pm, β = 110.610(3)° at 20 °C corroborate earlier results for this compound. The Raman and IR spectra of Cs[C2N3] are presented for the first time and the result compares well with those of NaCs2[C2N3]3. The heat-driven cyclotrimerization process of Cs[C2N3] was studied by thermal analyses (DSC) and temperature-dependent X-ray powder diffraction methods. At 370 °C, its trimerization product Cs3[C6N9] is formed, crystallizing in the orthorhombic space group Pbam with the cell parameters a = 3043.0(3), b = 1052.4(1) and c = 415.21(4) pm for Z = 4. The IR spectrum of this cesium tricyanomelaminate (Cs3[C6N9] or Cs3[TCM]) is presented, but a well-resolved Raman spectrum could not be acquired owing to fluorescence phenomena. An overview about the cyclotrimerization reactions of all pseudo-binary alkali-metal dicyanamides (A[C2N3]) to their corresponding tricyanomelaminates (A 3[C6N9]) with A = Li–Cs gives a basis for a discussion of the different thermal and structural characteristics.

Synthesis and characterization of ternary trielides Na7KTr4 [Tr=In or Tl] including [Tr4]8− Tetrahedra

AbstractTwo new ternary trielides Na7KTr4 (Tr=In, Tl) have been prepared by classical solid‐state reaction from the elements in tantalum ampoules. Both are isostructural to Na7RbTl4 and therefore crystallize in the orthorhombic space group Pbam, Pearson symbol oP96 (a=b=16.3283(2)/16.2860(6), c=11.3094(17)/11.2771(4), V=3015.25(8)/2991.07(18), Z=8, R1, wR2=0.0249, 0.0386/0.0447, 0.0608). The trielide subunit is built by two crystallographically independent [Tr4]8− tetrahedra. 23Na‐MAS‐Nuclear Magnetic Resonance (NMR) as well as EPR spectroscopy was employed to characterize the compounds further. DOS calculations showed a (pseudo) band gap at EF for both compounds. Dissolution experiments in liquid ammonia were carried out for the two alkali metal indides Na7KIn4 and Na2In according to the chemistry of group 14 and 15 Zintl anions. After evaporating the solvent, the remaining material was analyzed by powder X‐ray diffraction and proved the formation of NaIn and NaNH2.

KRb2(NO3)2Cl: a new birefringent crystal exhibiting a perovskite-related framework and a short cutoff edge.

The combination of π-conjugated groups [NO3] and Cl-centered polyhedra generates a new birefringent crystal with a perovskite-related framework, KRb2(NO3)2Cl, which is the first alkali metal nitrate chloride synthesized by a mild hydrothermal method. It crystallizes in the orthorhombic space group pbam (no. 55). In addition, KRb2(NO3)2Cl crystals with dimensions up to 7 × 1.5 × 1 mm3 were grown. Notably, KRb2(NO3)2Cl has a short UV cut-off edge (below 228 nm) and a significantly enhanced birefringence (Δn = 0.084 at 1064 nm). Theoretical calculations indicate that the birefringence enhancement mainly derives from π-conjugated [NO3] plane triangles.

Thermoelectric Properties of p‐ and n‐type Eu5Sn2As6

AbstractEu5Sn2As6 is a Zintl phase crystalizing in the orthorhombic space group Pbam with one‐dimensional chains of corner‐shared SnAs4 tetrahedra running in the c‐direction. Eu5Sn2As6 has an impressive room temperature Seebeck of >100 μV/K and < – 100 μV/K at 600 K crossing from p‐ to n‐type at 650 K. The maximum thermoelectric figure of merit, zT, for Eu5Sn2As6 is small (0.075), comparable to that of the Zintl phase Ca5Al2Sb6 whose thermoelectric performance was improved by doping Na onto the Ca sites. In this study, we show that the thermoelectric properties of Eu5Sn2As6 can be improved by substituting with K or La. The series Eu5‐xKxSn2As6 provides an increase in maximum zT of 0.22 for x=0.15 due to a decrease resistivity while the onset of bipolar conduction systematically increases in temperature. Upon La substitution, Eu5‐xLaxSn2As6 results in a new n‐type Zintl phase across the temperature range of 300–800 K.

Structural, vibrational, thermal, and magnetic properties of mullite‐type NdMnTiO5 ceramic

AbstractMullite‐type RMn2O5 (R = Y, rare‐earth element) ceramics are of ongoing research attention because of their interesting crystal‐chemical and magnetic properties. We report nuclear and magnetic structures of NdMnTiO5 together with its spectroscopic, thermogravimetric, and magnetic properties. The polycrystalline sample is prepared by solid‐state synthesis and characterized from neutron and X‐ray powder diffraction data Rietveld refinements. NdMnTiO5 crystallizes in the orthorhombic space group Pbam with metric parameter a = 755.20(1) pm, b = 869.91(1) pm, c = 582.42(1) pm, and V = 382.62(1) 106 pm3. The Mn3+ and Ti4+ cations are observed to be located in the octahedral and pyramidal sites, respectively. The vibrational features in these polyhedral sites are characterized by Raman and Fourier transform infrared spectroscopes. The higher decomposition temperature of NdMnTiO5, compared to other RMn2O5 phases, is explained in terms of the higher bond strength of Ti‐O bonds than those of Mn‐O bonds. Temperature‐dependent DC magnetic susceptibility suggests a paramagnetic to antiferromagnetic phase transition at 43(1) K. Inverse susceptibility in the paramagnetic region above 120 K follows the Curie‐Weiss law, resulting in a magnetic moment of 6.33(1) μB per formula unit. Neutron diffraction data collected at 7.5 K reveal that the magnetic moments of Nd3+ and Mn3+ in NdMnTiO5 are incommensurately ordered with a propagation vector k = (0, 0.238, 0.117).

Structural and thermoelectric properties of Pb4In2.6Bi3.4Se13

Quaternary selenide, Pb4In2.6Bi3.4Se13 (x = 2.4 member of the Pb4(InxBi6-xSe13 solid solution), was synthesized by a solid-state technique, and its structure was determined using powder X-ray diffraction (XRD). Pb4In2.6Bi3.4Se13 crystallizes in the orthorhombic space group Pbam (No. 55) with Z = 4. Lattice parameters and calculated density were determined to be a = 22.152(5) Å, b = 27.454(5) Å, and c = 4.1354(6) Å, V = 2515.0(11) Å3, and Dx = 7.490 g cm−3. The structure consists of Z-shaped ribbon units and corner-shared infinite one-dimensional [InSe4]∞ chains running parallel to the c-axis. The chains and ribbons are further connected by Pb atoms to form a three-dimensional network. Pb atoms are situated in the center of bicapped trigonal prisms. The compound exhibits a semiconductor feature. The Seebeck coefficient of Pb4In2.6Bi3.4Se13 was found to be −180 μV K−1 at 295 K and −380 μV K−1 at 600 K. Combining the values of Seebeck coefficient, electrical conductivity, and thermal conductivity yield a figure of merit, ZT, of about 0.175 at 700 K. The powder XRD pattern of Pb4In2.6Bi3.4Se13 was also determined.

Human plasma protein corona decreases the toxicity of pillar-layer metal organic framework

This scenario was designed to investigate the protein corona pattern on the pillar-layer surface of a Cu-based metal–organic framework (MOF) in human plasma. The [Cu(L)(L/)].1.3DMA (MOF-1) {L = 4, 4/-bipyridine and L/ = 5-aminoisophthalic acid}, was synthesized through the sonochemical irradiation approach as well as characterized by various techniques like scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray powder diffraction and single-crystal X-ray diffraction. The space group was determined to be an orthorhombic space group (Pbam) by single-crystal X-ray diffraction. Single-crystal X-ray analyses on MOF-1 showed that Cu+2 ion was 6-coordinated. Besides, to study and clarify interactions between MOFs and biological milieu, human whole blood plasma was selected as a model. Fluorescence spectroscopy and SDS-PAGE techniques were employed to explore quantitative and qualitative in situ characterization of protein corona as well. Furthermore, cell viability in a cancerous cell lines was evaluated by MTT assay in the presence and absence of the corona. The results from SDS-PAGE illustrated that the most adsorbed quantity among plasma proteins belongs to fibrinogen (α, β and γ chains), and this protein showed the maximum frequency on the MOF-1s surface, so the possible interactions of MOF-1s with fibrinogen also studied using fluorescence spectroscopy and corresponding data were plotted. According to the obtained data from MTT assay, these structures have concentration-dependent toxicity. In brief, based on the obtained data in the current study, the designed MOF can be introduced as a new desirable carrier for drug/gen delivery after further prerequisite assessments.

Exploring New Zintl Phases in the 9-4-9 Family via Al Substitution. Synthesis, Structure, and Physical Properties of Ae9Mn4-xAlxSb9 (Ae = Ca, Yb, Eu).

Three new quaternary Zintl phases with the "9-4-9" formula, Ae9Mn4-xAlxSb9 (Ae = Ca, Yb, Eu), have been synthesized using Pb as the metal flux, and their crystal structures have been established by single-crystal X-ray diffraction. Both Ca9Mn2.91(4)Al1.09Sb9 and Yb9Mn3.59(6)Al0.41Sb9 are isostructural with Ca9Mn4Bi9, and they crystallize in the orthorhombic space group Pbam with unit cell dimensions of a = 12.4571(8), 12.2884(16) Å, b = 22.1352(16), 22.024(3) Å, and c = 4.6012(3), 4.6187(6) Å, respectively. Their anionic structures can be viewed as infinite ribbons based on corner-shared tetrahedrons. Also, Eu9Mn2.87(4)Al1.13Sb9 has the space group Cmca and a = 9.4883(7) Å, b = 23.6895(18) Å, and c = 24.4845(19) Å. The structural relationships between Ca9Mn2.91(4)Al1.09Sb9 and Eu9Mn2.87(4)Al1.13Sb9 are compared and discussed as well. The successful Al3+ substitution provides additional electrons to the compounds to achieve structural stability. Magnetic susceptibility and electrical resistivity measurements, performed on single crystals of Eu9Mn2.87(4)Al1.13Sb9, indicate complex magnetic properties and semiconductor behavior. The physical properties of Yb9Mn3.59(6)Al0.41Sb9 are similar to those observed for Yb9Mn4.18(2)Sb9.

Enhancement of Solar Energy Absorption and Optoelectronic Properties of SrCuSbS3 by Lead Doping

Copper antimony sulfides (CAS) are of great interest for their applications in solar absorbers. Here, a new series of CAS materials is reported, namely the Sr1−xPbxCuSbS3 (x = 0–0.2), which are synthesized via solid state reactions. The new compound SrCuSbS3 crystallizes in the orthorhombic space group Pbam and consists of 3D [CuSbS3]2− extended framework and Sr2+ ions. The [CuSbS3]2− framework is constructed by [CuS3]5− one‐dimensional chains and [SbS3]3− triangular pyramids. The compound is a semiconductor with a band gap of 1.91 eV. Partial replacement of Sr2+ by Pb2+ can narrow the band gap to 1.63 eV when the doping concentration is up to 20%. First‐principles calculations reveal that the SrCuSbS3 compound is a direct band gap semiconductor with the valence band maximum composed of Cu‐3d states and the conduction band minimum composed of Sb‐5p‐S‐3p states. The Pb orbitals play critical roles in narrowing the band gap of Sr1‐xPbxCuSbS3 (x = 0–0.2). The series of CAS materials also show evident photoelectric response properties which demonstrate their potential for applications for photovoltaic devices. In addition, these CAS materials are good photocatalysts for the photodegradation reaction of Rhodamine B (RhB). The Sr0.8Pb0.2CuSbS3 powder can degrade 100% of RhB within 3 h under simulated sunlight.

Rare-Earth Metal Substitutions in Ca9–xRExMn4Sb9 (RE = La–Nd, Sm; x ≈ 1). Synthesis and Characterization of a New Series of Narrow-Gap Semiconductors

This paper details the synthesis and the structural characterization of the new antimonides with general formulas Ca9–xRExMn4Sb9 (RE = La, Ce, Pr, Nd, and Sm; x ≈ 1). The synthesis of these phases was accomplished by both high temperature reactions of the respective elements and by Pb-flux experiments. The structures were determined by single-crystal X-ray diffraction methods. All title compounds are isostructural and crystallize with the orthorhombic space group Pbam (No. 55). The structure is similar, but not isotypic to Ca9Mn4Bi9 (same space group; Pearson code oP44). On the basis of that, Ca9–xRExMn4Sb9 can be considered as new derivatives of this structure type, presenting the first examples of rare-earth metal substitutions within the “9-4-9” family of compounds. Electrical resistivity measurements confirm the successful electron doping, achieved by the aliovalent replacement of Ca2+ with RE3+ cations in the structure, leading to the emergence of narrow band-gap semiconducting behavior. Temperature-...

Li6M(SeO3)4 (M = Co, Ni, and Cd) and Li2Zn(SeO3)2: Selenites with Late Transition-Metal Cations.

A series of lithium metal selenites, Li6M(SeO3)4 (M = Co, Ni, and Cd) and Li2Zn(SeO3)2, were synthesized by hydrothermal and solid-state reactions. Li6M(SeO3)4 is composed of Li+ cations, MO6 octahedra, and SeO3 polyhedra, while Li2Zn(SeO3)2 consists of Li+, Zn(Li)O4 tetrahedra, and SeO3 polyhedra. Isostructural Li6Co(SeO3)4 and Li6Ni(SeO3)4 crystallize in the rhombohedral space group R3̅, forming a three-dimensional distorted cubic lattice. Li2Zn(SeO3)2 crystallizes in the orthorhombic space group Pbam and reveals a layered structure in the bc plane. Li6Cd(SeO3)4 revealing a unidimensional structure crystallizes in the polar non-centrosymmetric space group C2, attributed to the parallel alignment of distorted CdO6 octahedra. The direct-current magnetic susceptibility measurements unveil that Li6Co(SeO3)4 is a canted antiferromagnet with TN = 25 K, while Li6Ni(SeO3)4 undergoes an antiferromagnetic transition at TN = 54 K, having a negligible canted moment. The weak ferromagnetism observed in Li6Co(SeO3)4 indicates the significance of spin-orbit coupling, bringing about anisotropic exchange interactions. Li6Cd(SeO3)4 reveals a second harmonic generation (SHG) efficiency of 10 × α-SiO2. Dipole moment calculations on Li6Cd(SeO3)4 indicate that the cooperative interaction of CdO6 and SeO3 is responsible for the observed SHG properties. Band gaps of the compounds are enlarged as atomic number increases. The effect of late transition-metal cations with different coordination numbers on the framework structures and the subsequent physical properties will be also discussed.

Influence of Thermally Activated Solid-State Crystal-to-Crystal Structural Transformation on the Thermoelectric Properties of the Ca5–xYbxAl2Sb6 (1.0 ≤ x ≤ 5.0) System

The solid-solution Zintl compounds with the mixed cations of Ca2+and Yb2+ in the Ca5–xYbxAl2Sb6 (1.0 ≤ x ≤ 5.0) system have been synthesized by high-temperature solid-state reactions. Two slightly different crystal structures of the Ba5Al2Bi6-type and Ca5Ga2Sb6-type phases have been characterized for seven compounds with 2.5 ≤ x ≤ 5.0 and three compounds with 1.0 ≤ x ≤ 2.0, respectively, by both powder and single-crystal X-ray diffraction analyses. The two title phases adopt the orthorhombic space group Pbam (Z = 2, oP26) with seven independent asymmetric atomic sites and share certain structural similarities, including infinite one-dimensional [Al2Sb8] double chains and isolated space-filling Ca2+/Yb2+ cations. Interestingly, we reveal the crystal-to-crystal solid-state structural transformation of the Yb-rich compound Ca1.5Yb3.5Al2Sb6 from the Ba5Al2Bi6-type to the Ca5Ga2Sb6-type phase through the postannealing process, which can be rationalized as the phase transition from the kinetically more stable s...

Synthesis, crystal structure and electronic structure of the binary phase Rh2Cd5

A new phase in the Rh-Cd binary system - Rh2Cd5 has been identified and characterized by single crystal X-ray diffraction and Energy dispersive X-ray analysis. The stoichiometric compound Rh2Cd5 crystallizes with a unit cell containing 14 atoms, in the orthorhombic space group Pbam (55). The crystal structure of Rh2Cd5 can be described as a defect form of the In3Pd5 structure with ordered vacancies, formed of two 2D atomic layers with the stacking sequence: ABAB. The A type layers consist of (3.6.3.6)-Kagomé nets of Cd atoms while the B type layers consist of (35) (37)- nets of both Cd and Rh atoms. The stability of this line phase is investigated by first principle electronic structure calculations on the model of ordered Rh2Cd5.

Synthesis, Structure, and Complex Magnetism of MIr2In8 (M = Eu, Sr).

We report the synthesis, crystal structure, and physical properties of two new polar intermetallic compounds, EuIr2In8 and SrIr2In8. Both were synthesized in good yield using In metal as a reactive flux medium, enabling the growth of large crystals for physical property measurements. They crystallize in the orthorhombic space group Pbam with the CeFe2Al8 structure type, which is sometimes also referred to as the CaCo2Al8 structure type. The two analogues have unit cell parameters of a = 13.847(3) Å, b = 16.118(3) Å, and c = 4.3885(9) Å for M = Eu and a = 13.847(3) Å, b = 16.113(3) Å, and c = 4.3962(9) Å for M = Sr at room temperature. SrIr2In8 is a diamagnetic metal with no local magnetic moments on either the Sr or Ir sites, and the diamagnetic contribution from core electrons overwhelms the expected Pauli paramagnetism normally seen in intermetallic compounds. Magnetism in EuIr2In8 is dominated by the local Eu moments, which order antiferromagnetically at 5 K in low applied fields. Increasing the field strength depresses the magnetic ordering temperature and also induces a spin reorientation at lower temperature, indicating complex competing magnetic interactions. Low-temperature heat capacity measurements show a significant enhancement of the Sommerfeld coefficient in EuIr2In8 relative to that in SrIr2In8, with estimated values of γ = 118(3) and 18.0(2) mJ mol(-1) K(-2), respectively.

Synthesis and characterization of the rare-earth Dion-Jacobson layered perovskites, APrNb2O7 (A = Rb, Cs and CuCl).

The new double-layered perovskites, APrNb(2)O(7) (A = Rb, Cs) have been prepared by a high temperature ceramic method. Rietveld refinement of X-ray powder diffraction data confirmed the orthorhombic and tetragonal structures, respectively; RbPrNb(2)O(7) was refined in space group Imma (a = 5.4534(7) Å, b = 22.012(1) Å, c = 5.4549(7) Å) and CsPrNb(2)O(7) in P4/mmm (a = 3.8668(2) Å, c = 11.163(1) Å). (CuCl)PrNb(2)O(7), topochemically prepared by replacement of Rb(+)/Cs(+) with CuCl(+), contains a 2D Cu-Cl network between the PrNb(2)O(7) slabs (orthorhombic space group Pbam, a = 7.7328(6) Å, b = 7.7113(4) Å and c = 11.6706(3) Å). The parent compounds both show paramagnetic behavior μ(eff) (Rb) = 3.34(1)μ(B) and μ(eff) (Cs) = 3.60(2)μ(B) while the (CuCl)PrNb(2)O(7), paramagnetic (μ(eff) = 4.020(8)μ(B)) down to 20 K, exhibits antiferromagnet-like behavior below 20 K.

Complex transition metal hydrides incorporating ionic hydrogen: Synthesis and characterization of Na2Mg2FeH8 and Na2Mg2RuH8

A new class of quaternary complex transition metal hydrides (Na2Mg2TH8 (T=Fe, Ru)) have been synthesized and their structures determined by combined synchrotron radiation X-ray and powder neutron diffraction. The compounds can be considered as a link between ionic and complex hydrides in terms of incorporating independently coordinated ionic and covalent hydrogen. These novel isostructural complex transition metal hydrides crystallize in the orthorhombic space group Pbam, where the octahedral complex hydride anion is surrounded by a cubic array of four Mg2+ and four Na+ cations, forming distinct two-dimensional layers. An intriguing feature of these materials is the distorted octahedral coordination of the isolated H− anions by four Na+ and two Mg2+ cations, which form layers between the transition metal containing layers. The vibrational modes of the H− anions and complex hydride anion are independently observed for the first time in a quaternary complex transition metal hydride system by Raman and IR spectroscopy.

NaIn3S5, a new compound from the CaS–In2S3/NaBr system

A new compound NaIn3S5 has been obtained in the CaS–In2S3/NaBr system via a reactive flux method. NaIn3S5 crystallizes in the orthorhombic space group Pbam (No. 55) with a=12.4963(8)Å, b=16.0811(10)Å, c=3.8041(2)Å, and Z=4. The NaIn3S5 structure is characterized by a three dimensional framework consisting of interconnected tripartite-octahedral [In3S8]∞1 infinite chains, with Na+ cations residing in the one-dimensional channels along the c direction defined by S(1), S(2), S(3) and S(4) atoms. The optical reflectance measurement shows a band gap of 2.18eV for NaIn3S5. Electronic structure calculation by the CASTEP code not only indicates that NaIn3S5 is an indirect band gap semiconductor, but also explains why its experimental band gap is close to that of β-In2S3.

Synthesis and crystal structures of RE7Zn(21+x)Si(2-x) [RE = Ce, Pr, and Nd; 0.09 (1) < x < 0.95 (1)

The focus of this paper is on the synthesis and crystal structures of three Zn-rich compounds with the general formula RE7Zn(21+x)Si(2-x), where RE = Ce [x = 0.95 (1); heptacerium docosazinc silicon], Pr [x = 0.09 (1); heptapraseodymium henicosazinc disilicon], and Nd [x = 0.53 (1); heptaneodymium docosazinc silicon]. The compounds were obtained by high-temperature reactions, using the respective elements as starting materials. The structures were determined by single-crystal X-ray diffraction. The title compounds crystalize in the orthorhombic space group Pbam (No. 55, Pearson symbol oP60) and are isostructural with about a dozen RE7Zn(21+x)Tt(2-x) (RE = La-Nd; Tt = Ge, Sn, and Pb) compounds previously reported by our group. The results from the present refinements confirm the previously published data on RE7Zn(21+x)Si(2-x) (RE = La and Ce; x ≃ 1.45) [Malik et al. (2013). Intermetallics, 36, 118-126]. Additionally, magnetic susceptibility measurements on the corresponding bulk samples show Curie-Weiss paramagnetic behavior from 5 to 300 K, consistent with RE(3+) ground states and local-moment magnetism due to the core 4f electrons.

Subsolidus phase relations in CoO–In2O3–B2O3 system and crystal structure of Co3−XInXBO5 solid solution for 0 < X ⩽ 1

Subsolidus phase equilibrium of CoO–In2O3–B2O3 system has been investigated mainly by solid-state reaction and powder X-ray diffraction method. A novel compound Co2InBO5 was found and synthesized for the first time. There are five definite three-phase regions and one solid solution Co3−XInXBO5 (0<X⩽1) in this system under present experimental conditions. This new compound Co2InBO5 and high temperature metastable phase Co3BO5 can form continuous solid solution at all relative concentrations. Crystal structure of three representative Co3−XInXBO5 solid solution compounds (X=0.4, 0.7, and 1) were refined and determined from X-ray powder diffraction data using Rietveld method. The results showed that the Co3−XInXBO5 (0<X⩽1) solid solution crystallized in the orthorhombic space group Pbam (No. 55) with the ludwigite structure type. The lattice parameters (a, b and c) of these solid solution compounds increase linearly when In replace Co atom gradually (i.e. with the increase of the value of X), which obeys the Vegard’s rule. The trigonal BO3 group in these Co3−XInXBO5 solid solution compounds was confirmed by their infrared absorption spectra.

Yb5Ga2Sb6: A Mixed Valent and Narrow-Band Gap Material in the RE5M2X6 Family

A new compound Yb5Ga2Sb6 was synthesized by the metal flux technique as well as high frequency induction heating. Yb5Ga2Sb6 crystallizes in the orthorhombic space group Pbam (no. 55), in the Ba5Al2Bi6 structure type, with a unit cell of a = 7.2769(2) Å, b = 22.9102(5) Å, c = 4.3984(14) Å, and Z = 2. Yb5Ga2Sb6 has an anisotropic structure with infinite anionic double chains (Ga2Sb6)(10-) cross-linked by Yb(2+) and Yb(3+) ions. Each single chain is made of corner-sharing GaSb4 tetrahedra. Two such chains are bridged by Sb2 groups to form double chains of 1/∞ [Ga2Sb6(10-)]. The compound satisfies the classical Zintl-Klemm concept and is a narrow band gap semiconductor with an energy gap of around 0.36 eV calculated from the electrical resistivity data corroborating with the experimental absorption studies in the IR region (0.3 eV). Magnetic measurements suggest Yb atoms in Yb5Ga2Sb6 exist in the mixed valent state. Temperature dependent magnetic susceptibility data follows the Curie-Weiss behavior above 100 K and no magnetic ordering was observed down to 2 K. Experiments are accompanied by all electron full-potential linear augmented plane wave (FP-LAPW) calculations based on density functional theory to calculate the electronic structure and density of states. The calculated band structure shows a weak overlap of valence band and conduction band resulting in a pseudo gap in the density of states revealing semimetallic character.