Interfaces between polycyclic -electron systems and metals play prominent roles in organic or graphene-based (opto)electronic devices, in which performance-related parameters depend critically on the properties of metal/semiconductor contacts. Here, we explore how the topology of the -electron system influences the bonding and the electronic properties of the interface. We use azulene as a model for nonalternant pentagonheptagon (5-7) ring pairs and compare it to its isomer naphthalene, which represents the alternant 6-6 ring pair. Their coverage-dependent interaction with Ag(111) and Cu(111) surfaces was studied with the normal-incidence X-ray standing wave (NIXSW) technique, near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, UV and X-ray photoelectron spectroscopy (UPS, XPS), and density functional theory (DFT). Coveragedependent adsorption heights and spectroscopic data reveal that azulene forms shorter interfacial bonds than naphthalene and engages in stronger electronic interactions with both surfaces. These differences are more pronounced on Cu. Increasing coverages lead to larger adsorption heights, indicating bond weakening by intermolecular repulsion. The extensive DFT calculations include dispersive interactions using: (1) the DFT-D3 scheme, (2) the vdW surf correction based on DFT-TS, (3) a Many-Body Dispersion (MBD) correction scheme, and (4) the D3 surf scheme. All methods predict the adsorption heights reasonably well with an average error below 0.1 Å. The stronger bond of azulene is attributed to its nonalternant topology, which results in a reduced HOMO-LUMO gap and brings the LUMO energetically close to the Fermi energy of the metal, causing stronger hybridization with electronic states of the metal surfaces.

X-ray structure determinations of tetrakis(trifluoromethyl)diphosphane (2c, mp -82 degrees C, triclinic, P&onemacr;; Z = 1, a = 529.7(3) pm, b = 681.6(2) pm, c = 802.8(3) pm, alpha = 108.58(1) degrees, beta = 99.66(1) degrees, gamma = 103.29(1) degrees, wR2 = 0.204) and -diarsane (3c, mp -52 degrees C, monoclinic, P2(1)/c; Z = 2, a = 769.5(3) pm, b = 750.0(3) pm, c = 960.7(2) pm, beta = 105.26(1) degrees, wR2 = 0.115), both at -100(3) degrees C, reveal the molecules to adopt the trans conformation in the solid. Compared with the tetramethyl derivatives, the E-E (224.6(2)/246.3(1) pm, E = P, As) and E-C (188.3(4)/201.3(7) pm) bonds are elongated by 4.5/4.8 pm and 3.4/3.4 pm, respectively. From gas electron diffraction studies of diphosphane 2c a mixture of 85(10)% trans and 15(10)% gauche conformers can be deduced; diarsane 3c shows the trans form exclusively. The molecular parameters (E-E, 224.8(11)/245.2(6); E-C, 189.6(4)/ 201.2(4) pm) agree excellently with those determined for the crystalline state. As a result of quantum chemical calculations at Hartree-Fock and hybrid density functional levels of theory using 6-311+G basis sets, the gauche conformer of hydrazine derivative 1c and the trans conformer of diarsane 3c are clearly lowest in energy. However, for diphosphane 2c the gauche and not the trans form is found to be slightly more stable. Variations of calculated E-E and E-C bond lengths are analyzed and compared with corresponding values of the parent compounds E(2)H(4) (1a to 3a) as well as the tetramethyl derivatives 1b to 3b.

The crystal structure of β-MnF 4 has finally been elucidated. It crystallizes in the non-centrosymmetric space group R3c, no. 161, hR360, with the lattice parameters a = 19.390(3), c = 12.940(3) Å, V = 4213.3(14) Å 3 , Z = 72, T = 100 K. It is a 4a ϫ 4a superstructure of the VF 3 (FeF 3) structure type. The Mn atoms are coordinated octahedron-like by F atoms, of which two are bound terminal, while the other act as μ-bridging F atoms to other Mn atoms forming a threedimensional infinite network structure which can be described by the Niggli formula 3 ϱ [MnF 4/2 F 2/1 ]. Voids on the metal sites, which are oc

Professor Josef Goubeau in memoriamInhaltsu È bersicht. Chlordiphenylstiban (1 d) {P2 1 /c; Z = 4; a = 1191,8(1); b = 853,4(1); c = 1112,0(1) pm; b = 93,60(1)°; ±100 ± 2°C} kristallisiert isotyp zu einer Reihe homologer Verbindungen der Zusammensetzung (H 5 C 6 ) 2 E±X (E = As, X = Cl, Br, I; E = Sb, X = Br, I); der Strukturtyp des Tribenzylstibans (5 d) {Pbca; Z = 8; a = 832,1(2); b = 2681,3(5); c = 1600,9(3) pm; ±100 ± 3°C} ist vom Tribenzylmethanol, -silanol und -silan her bekannt. Demgegenu È ber weist Tribenzyldibromstiboran (6) {P2 1 /n; Z = 4; a = 938,4(2); b = 2292,4(5); c = 1019,7(2) pm; b = 112,71(1)°; ±100 ± 3°C} keine entsprechenden Beziehungen zu bereits bekannten Strukturtypen auf. Charakteristische, gemittelte Bindungsla È ngen und -winkel sind {1 d: Sb±Cl 240,9(1); Sb±C 214,0 pm; Cl±Sb±C 93,8; C±Sb±C 98,6(1)°; 5 d: Sb±C 217,5(3) pm; C±Sb±C 94,9(6)°; 6: Sb±Br 264,6; Sb±C 217,0(8) pm; Br±Sb±Br 179,4(1)°; C±Sb±C 120°; Br±Sb±C 84,8(2)°bis 94,7(2)°}. Beim Stiboran 6 deuten sich sehr schwache intermolekulare Antimon´´Brom-Wechselwirkungen (Sb´´Br 417 pm) an; sie wirken sich jedoch in auffallender Weise auf die Moleku È lkonformation aus. Element±Element Bonds. X. Studies of Chloro(diphenyl)stibane, Tribenzylstibane and Tribenzyldibromostiborane ± Molecular Structures and Isotypism Abstract. Chlorodiphenylstibane (1 d) {P2 1 /c; Z = 4; a = 1191.8(1); b = 853.4(1); c = 1112.0(1) pm; b = 93.60 (1)°; ±100 ± 2°C} crystallizes isotypically with a series of homologous (H 5 C 6 ) 2 E±X compounds (E = As, X = Cl, Br, I; E = Sb, X = Br, I); the structure type of tribenzylstibane (5 d) {Pbca; Z = 8; a = 832.1(2); b = 2681.3(5) pm; c = 1600.9(3); ±100 ± 3°C} is already known from tribenzylmethanol, -silanol and -silane. Tribenzyldibromostiborane (6) {P2 1 /n; Z = 4; a = 938.4(2); b = 2292.4(5); c = 1019.7(2) pm; b = 112.71(1)°; ±100 ± 3°C} does not show an analogous relationship to known structure types. Characteristic mean bond lengths and angles are {1 d, Sb±Cl 240.9(1), Sb±C 214.0 pm, Cl±Sb±C 93.8°, C±Sb±C 98.6(1)°; 5 d, Sb±C 217.5(3) pm, C±Sb±C 94.9(6)°; 6, Sb±Br 264.6; Sb±C 217.0(8) pm, Br±Sb±Br 179.4(1)°; C±Sb±C 120°; Br±Sb±C 84.8(2)°to 94.7(2)°}. Stiborane 6 exhibits very weak intermolecular Sb´´Br interactions of 417 pm which, however, affect the molecular conformation in a striking way.

Herein we present the crystal structure of lithium hexafluoridoplumbate(IV) determined from powder X‐ray diffraction data. The cell parameters are a = 5.01067(3), c = 4.66340(5) Å, V = 101.3969(13) Å3 at T = 293 K. Li2PbF6 is isotypic to Li2ZrF6, space group P31m (no. 162). The measured Raman spectrum is compared with the quantum chemically calculated spectrum. Furthermore, we determined the decomposition temperature of Li2PbF6. We also present the corrected space group and crystal structure for SrPbF6 which was previously reported as P42/mmc (no. 131) and could now be corrected to space group P42/mcm [no. 132, a = 5.21719(3), c = 8.92771(11) Å, V = 243.004(4) Å3, T = 293 K].

A Li4Ti5O12 (LTO) film was coated as buffer layer onto a LiNi0.5Mn1.5O4 (LNMO) high-voltage cathode, and after cycling of the cathode in a battery electrolyte, the LTO film was investigated by means of synchrotron radiation based hard X-ray photoelectron spectroscopy (HAXPES). By tuning the photon energy between 2 keV and 6 keV, we obtained non-destructive depth profiles of the coating material with probing depths ranging from 6 nm to 20 nm. The coating was found to be covered by a few nanometers thin surface layer resulting from electrolyte decomposition. This layer consisted predominantly of organic polymers as well as metal fluorides and fluorophosphates. A positive influence of the Li4Ti5O12 coating with regard to the size and stability of the surface layer was found. The coating itself consisted of a uniform mixture of Li(I), Ti(IV), Ni(II) and Mn(IV) oxides that most likely adopted a spinel structure by forming a solid solution of the two spinels LiNi0.5Mn1.5O4 and Li4Ti5O12 with Li, Mn, Ni and Ti cations mixing on the spinel octahedral sites. The diffusion of Ni and Mn ions into the Li4Ti5O12 lattice occurred during the heat treatment when preparing the cathode. The doping of Li4Ti5O12 with the open d-shell ions Ni(2+) (d(8)) and Mn(4+) (d(3)) should increase the electronic conductivity of the coating significantly, as was found in previous studies. The complex signal structure of the Ti 2p, Ni 2p and Mn 2p core levels provides insight into the chemical nature of the transition metal ions.

The binary lead fluoride Pb3F8 was synthesized by the reaction of anhydrous HF with Pb3O4 or by the reaction of BrF3 with PbF2. The compound was characterized by single‐crystal and powder X‐ray diffraction, IR, Raman, and solid‐state MAS 19F NMR spectroscopy, as well as thermogravimetric analysis, XP and near‐edge X‐ray absorption fine structure (NEXAFS) spectroscopy. Solid‐state quantum‐chemical calculations are provided for the vibrational analyses and band assignments. The electronic band structure offers an inside view of the mixed valence compound.

The compound PbF[Br 2 F 7 ] represents the first fluoridobromate(III) of a p-block element. It was synthesized in form of needle-shaped crystals among its colorless powder from the direct reaction of PbF 2 with BrF 3 . Powder X-ray diffraction, IR and Raman spectroscopy show that it was obtained in almost pure form with Pb 3 F 8 and Pb 2 F 6 as by-products. The single crystal structure was determined by X-ray diffraction. PbF[Br 2 F 7 ] crystallizes in space group P2 1 /c (No. 14) with a = 4.3698(3), b = 13.3767 (7), c = 12.0836(8) Å, = 97.509(5)°, V = 700.27(8) Å 3 , [a]