Boron-doped hydrogenated microcrystalline silicon oxide (μc-SiOx:H) for application in thin-film silicon solar cells

We report on the development of p-type μc-SiO_x:H material, in particular the relationship between the deposition parameters and the material properties like band gap, electrical conductivity, and crystalline volume fraction. The material was deposited from gas mixtures of silane, carbon dioxide and hydrogen by RF-PECVD. The gas flows were varied systematically to evaluate their influence on the material properties. An increase of the oxygen content in the material disturbs the crystalline growth. This can be counteracted by appropriate hydrogen dilutions. Materials with a combination of reasonably high conductivity of 4 × 10^? 6 S/cm at a high optical band gap E₀₄ of 2.56 eV and a refractive index of 1.95 are obtained. Applied in single junction μc-Si:H pin solar cells the improved properties of the μc-SiO_x:H p-layers are reflected in higher quantum efficiency in the short wavelength range by 10% compare to cells without adding CO₂ during p-layer deposition.     

Chelation of a diphosphine ligand at FeCo2(CO)9(μ3-S): Spectroscopic and X-ray diffraction data for FeCo2(CO)7(bpcd)(μ3-S)

The tetrahedrane cluster, FeCo₂(CO)₉(₃-S), reacts with the redox-active ligand, 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd), to give the disubstituted cluster, FeCo₂(CO)₇(bpcd)(₃-S), as the sole product. This diphosphine-substituted cluster contains a cobalt-bound, chelating bpcd ligand. Both IR and ³¹P NMR spectroscopies have been employed in the solution characterization of FeCo₂(CO)₇(bpcd)(₃-S), and the solid-state structure has been unequivocally established by X-ray diffraction analysis. FeCo₂(CO)₇(bpcd)(₃-S) crystallizes in the monoclinic space group C2/c, a = 34.494(3) Å, b = 11.4194(9) Å, c = 18.634(2) Å, = 98.103(7)°, V = 7266.7(9) ų, Z = 8, and d_calc = 1.584 g/cm³. Cyclic voltammetric studies on FeCo₂(CO)₇(bpcd)(₃-S) reveal the presence of two quasireversible redox responses assigned to the 0/1^– and 1^–/2^– redox couples. The orbital composition of these redox couples has been examined by carrying out extended Hückel MO calculations on the model complex FeCo₂(CO)₇(H₄-bpcd)(₃-S), with the results being compared to related cluster compounds.     

Carbon–hydrogen and carbon–phosphorus bond cleavage in a triruthenium cluster complex containing dppm: The crystal and molecular structures of Ru3(CO)6{μ 3-OPPh2 C2H(C6H4)PPhCH2PPh}(μ 3-OPPh2)Ph and Ru3(CO)6 {μ-OPPh2C2H(C6H4)PPhO}(μ-PPh2)(μ-PPh2O)

The crystal and molecular structures of Ru₃(CO)₆{μ ₃-OPPh₂C₂H(C₆H₄)PPhCH₂PPh}-(μ ₃-OPPh₂)Ph (1) and Ru₃(CO)₆{μ-OPPh₂C₂H(C₆H₄)PPhO}(μ-PPh₂)(μ-PPh₂O) (2) have been determined by single crystal X-ray diffraction. Both complexes contain oxygen atoms oxidatively inserted into phosphorus–ruthenium bonds, and unique σ/π multidentate ligands formed from C $---{\text{H}}$ H and C $--$ P bond cleavage in bis(diphenylphosphino)acetylene and bis(diphenylphosphino)methane. Complex 1 crystallized in the triclinic space group ${\bar 1}$ , with lattice parameters a = 11.642(4) Å, b = 15.018(5) Å, c =16.587(5) Å, α = 2.48(3)°, β = 76.47(2)°, γ = 70.35(3)°, V = 2651.1(15) ų, Z = 2. Complex 2 crystallized in the centered monoclinic space group, C2/c, with lattice parameters a = 34.467(4) Å, b = 14.274(2) Å, c = 23.258(3) Å, β = 5.29(1)°, V = 11394(3) ų, Z = 8.     

Preparation and Characterization of Bis(μ-1,2-diaminoethane)cobalt(II) Hexavanadate: A Layered Polyoxovanadate Pillared by a Cobalt Coordination Complex

Abstract  The first example of polyoxovanadate layered framework with a cobalt coordination complex as a pillaring unit, Co^II(μ-C₂N₂H₈)₂[V₄^IVV₂^VO₁₄], was readily synthesized under hydrothermal conditions. The structure can be solved and refined in monoclinic P2 ₁ /n with a = 9.143(3) ?, b = 6.5034(11) ?, c = 15.874(4) ?, β = 101.90(2), V = 923.6(4) ?³ and Z = 2. The crystal structure comprises two-dimensional {V₄^IVV₂^VO₁₄}²⁻ layers extending parallel to [101], constructed from tetrahedral {V^VO₄} and square pyramidal {V^IVO₅} building units. Adjacent layers are linked through the octahedral {Co^IIO₂(μ-C₂N₂H₈)₂} pillars, within which the Co^II resides on an inversion center. The structure displays N–H···O and C–H···O hydrogen bonding between the ethylenediamine and vanadium oxide layers. Graphical Abstract  A new polyoxovanadate layered framework pillared with a cobalt coordination complex, Co^II(μ-C₂N₂H₈)₂[V₄^IVV₂^VO₁₄], has been prepared hydrothermally and fully characterized.      

Formation of a samarium alkoxide–aryloxide complex containing a novel butterfly framework: X-ray crystal structures of Sm4(μ3-O-i-Pr)3(μ2-O-i-Pr)4(O-i-Pr)2(O-2,6-i-Pr2C6H3)3(THF) and [Ti(O-i-Pr)2(O-2,6-i-Pr2C6H3) (μ-O-i-Pr)]2

Reaction of a 1:1 mixture of Sm[N(SiMe₃)₂]₃ and Ti(O-i-Pr)₄ with three equivalents of 2,6-di-iso-propylphenol, followed by crystallization from hexane/THF, leads to isolation of the tetranuclear samarium alkoxide Sm₄(₃-O-i-Pr)₃(₂-O-i-Pr)₄(O-i-Pr)₂(O-2,6-i-Pr₂C₆H₃)₃(THF) (1), in addition to the dimeric titanium alkoxide [Ti(O-i-Pr)₂(O-2,6-i-Pr₂C₆H₃)(-O-i-Pr)]₂ (2). 1 crystallizes in the space group while 2 crystallizes in space group P2₁/c. Cell parameters for 1: a = 15.928(6), b = 17.677(7), c = 18.99(1) Å, = 113.24(3), = 94.99(4), = 109.59(2)°, V = 4477(4) ų, D _calc = 1.350 Mg/m³, and Z = 2. Cell parameters for 2: a = 25.336(2), b = 12.082(1), c = 15.570(2) Å, = 96.510(8)°, V = 4735.4(8) ų, D _calc = 1.129 mg/m³, and Z = 4.     

Reaction of bis(dimethoxyphosphino)dimethylhydrazine (dmpdmh) with Ru3(CO)12: Evidence for facile ligand fragmentation in Ru3(CO)10(dmpdmh) to give Ru4(CO)12[μ-N(Me)N(Me)], Ru3(CO)11[P(OMe)3], and Ru3(CO)9[μ-P(OMe)3]

Thermolysis of the cluster Ru₃(CO)₁₂ with the bis(phosphanyl)hydrazine ligand (MeO)₂PN (Me)N(Me)P(OMe)₂ (dmpdmh) in toluene at 75°C furnishes the known clusters Ru₄(CO)₁₂ [-N(Me)N(Me)] (2) and Ru₃(CO)₁₁[P(OMe)₃] (3), in addition to the new cluster Ru₃ (CO)₁₀(dmpdmh) (1) and the phosphite-tethered cluster Ru₃(CO)₉[-P(OMe)₃] (4). The simple substitution product Ru₃(CO)₁₀(dmpdmh), a logical intermediate to clusters 2–4, was synthesized by treating Ru₃(CO)₁₂ with Me₃NO in CH₂Cl₂ at room temperature, and independent thermolysis reactions using cluster 1 was shown to yield clusters 2–4. The solid-state structure of clusters 2 and 4 were unequivocally established by X-ray diffraction analysis. Ru₄(CO)₁₂[-N(Me)N(Me)] crystallizes in the orthorhombic space group Pnna (#52), a = 12.913(1), b = 13.3238(6), c = 12.5690(8) Å, V = 2162.5(2) ų, Z = 4, and d _calc = 2.452 g/cm³. Ru₃(CO)₉[-P(OMe)₃] crystallizes in the triclinic space group P a = 9.586(1), b = 14.354(1), c = 14.997(2) Å, = 89.82(1)°, = 98.36(1)°, = 92.010(8)°, V = 2040.4(4) ų, Z = 4, and d _calc = 2.212 g/cm³. The coordination of the dimethylazo linkage to the four ruthenium atoms in 2 and the phosphorus atom and one of the oxygen atoms of the methoxy groups to the three ruthenium centers in 4 are confirmed by X-ray analysis.     

Reaction between [Ru3(CO)10(μ-dppm)] (dppm = Ph2PCH2PPh2) and Te2(C6H4OEt-4)2: X-ray crystal structure of [Ru2(CO)6{μ-C6H4PPh(CH2)PPh}]

Treatment of [Ru₃(CO)₁₀(-dppm)] (1) with the ditelluride Te₂(C₆H₄OEt-4)₂ in refluxing toluene afforded the new aryltellurol bridged complex [Ru₂(CO)₄(-TeC₆H₄OEt-4)₂ (-dppm)] (2) together with three known complexes [Ru₄(CO)₈(-CO)(₄-Te)₂(-dppm)] (3), [Ru₂(CO)₆{-CH₂PPh(C₆H₄)PPh}] (4), and [Ru₂(CO)₆{-C₆H₄PPh(CH₂)PPh}] (5). All the four complexes were characterized by spectroscopic methods, including an X-ray structure determination for 5. Complex 5 crystallizes in the monoclinic space group P2₁/c with a = 13.650(2), b = 9.995(2), c = 18.929(3) Å, = 97.49(2)°, V = 2560.4(8) ų, and Z = 4. In this complex the two ruthenium atoms are bridged by the phosphino-phosphide ligand C₆H₄PPh(CH₂)PPh which is attached to one Ru by the C₆H₄ group and a P atom while to the other Ru by both the two P atoms. Both the ruthenium atoms show distorted octahedral geometry. The Ru—Ru bond length is 2.8719(7) Å.     

Synthesis and crystal structure of [Cu(azpy)(H2O)4][Cu2(nta)2(azpy)]····6H2O: A two-dimensional network solid

The copper(II) complex [Cu(azpy)(H₂O)₄][Cu₂(nta)₂(azpy)]····6H₂O (nta = nitrilotriacetate, azpy = 4,4-azobispyridine) has been synthesized and structurally characterized. It crystallizes in the triclinic space group P , a = 8.6985(3) Å, b = 9.4776(3) Å, c = 14.6544(5) Å, = 71.5360(10)°, = 85.7600(10)°, = 88.1420(10)°, V = 1142.74(7) ų, Z = 1. The crystal structure consists of one-dimensional linear chain cations and dimeric anions. The copper centers in the anion possess distorted trigonal bipyramidal geometry, while Cu(2) has a distorted octahedral geometry in the cation. Coordinated water molecules in the one-dimensional chain form interionic hydrogen bonds with the oxygen atoms of the carboxylate of nta of the dimmer anion. These hydrogen bonds result in the formation of a two-dimensional network.     

Role of water molecules in protein-nucleic acid interactions: visualization of a model highly hydrated complex structure of Inosine 5′-monophosphate and L-Serine (2C10H13N4O8P·C3H7NO3·12H2O) at atomic resolution

The crystal structure of a dodecahydrated co-complex between two Inosine 5-monophosphate (IMP) and one L-serine, the first of its kind reported, has been determined at atomic resolution by X-ray crystallographic methods. The crystal belongs to a monoclinic space group, P2₁, with the cell dimensionsa=8.695(7),b=21.898(6),c=12.374(3)Å, =110.59(3)°. This structure reveals the recognition mechanism of serine to the nucleotides through direct and water-mediated hydrogen bonds. The phosphate oxygen (O22) seems to prefer the nonspecific interaction with the functional sites of serine (N...O22=2.735, OG...O22=2.970, O1...O22 =3.121 Å), whereas the bases prefer specific (N17...N=3.199, N23...O2=2.784 Å) bondings. The solvent-mediated hydrogen bonds N17...W3...N27 endow extra stabilization to the stacked bases. The presence of hydrogen-bonded water spines and their interplay in the specific and nonspecific bindings with potential ligands indicate the functional involvement of solvent molecules through cooperative donor-acceptor network and could act as viable centers of intricate interactions in protein-DNA complexation processes.     

Crystal structures of strontium and barium ethylenediaminetetraacetato cobaltates(III), Sr[CoEdta]2·9H2O and Ba[CoEdta]2·8H2O: Comparison of the structures of complexes in the series M’[CoEdta]2·nH2O (M’ = Mg, Ca, Sr, Ba; n = 7–10)

Cobalt(III) complexes, namely, Sr[CoEdta]₂·9H₂O (I) and Ba[CoEdta]₂·8H₂O (II) (where Edta ^4- is the ethylenediaminetetraacetate ion), are synthesized. The crystal structures of these compounds are determined using X-ray diffraction. Crystals of compound I are triclinic, a = 6.514(1) Å, b = 11.410(2) Å, c = 12.317(2) Å, α = 67.87(1)°, β = 88.73(2)°, γ = 84.22(2)°, V = 843.63(3) ų, Z = 1, space group P1, and R = 0.0295 for 4130 reflections with I > 2σ(I). Crystals of compound II are monoclinic, a = 6.543(2) Å, b = 12.895(3) Å, c = 19.489(4) Å, β = 95.24(3)°, V = 1637.5(5) ų, Z = 2, space group P2₁, and R = 0.050 for 3016 reflections with |F| > 3σ(|F|). The structures of compounds I and II are compared with those of the previously studied complexes Mg[CoEdta]₂·10H₂O (III) and Ca[CoEdta]₂·7H₂O (IV). The crystal structure of the cobalt(III) complex with the strontium cation (I) is topologically similar to the crystal structure of cobalt(III) complex with the calcium cation (IV). The former structure is built up of the two symmetrically independent homochiral anionic complexes [CoEdta]^? (A _I and B _I), the aqua cations [Sr(H₂O)₈]²⁺, and the molecules of crystalization water w _cr. The structure of compound II involves two independent anions [CoEdta]^? (A _II and B _II) with different chiralities (i.e., they are kryptoracemates). The A _II anions are linked via the barium cations into {Ba(H₂O)₇[CoEdta]} _1∞ ⁺ chain agglomerates due to the incorporation of two terminal oxygen atoms O_u of the anions neighboring in the chain into the coordination sphere of the barium atom. All four structures (I–IV) contain stacks composed of the [CoEdta]^? homochiral anions forming layers aligned parallel to the (001) plane. The aqua cations [Sr(H₂O)₈]²⁺, [Mg(H₂O)₆]²⁺, and [Ca(H₂O)₇]²⁺ or the partially hydrated barium cations [Ba(H₂O)₇(O_u)₂]²⁺ (in structure II), as well as water molecules w _cr, are located between the anion layers. The octahedral environment of the cobalt(III) atoms consists of donor atoms (2N and 4O) of the Edta ^4? ligand. The Co-N bonds in the A _I, B _I, A _II, and B _II anions [the mean bond lengths are 1.927(4), 1.921(4), 1.910(6), and 1.921(6) Å, respectively] are considerably longer than the Co-O bonds [the mean bond lengths are 1.908(5), 1.902(5), 1.904(6), and 1.908(6) Å, respectively]. The mean distances Sr-O_w and Ba-O_w in the strontium and barium polyhedra are 2.609(4) and 2.834(8) Å, respectively. The mean distance Ba-O_u is 2.814(7) Å.