SnIP is the first atomic-scale double helical semiconductor featuring a 1.86 eV bandgap, high structural and mechanical flexibility, and reasonable thermal stability up to 600 K. It is accessible on a gram scale and consists of a racemic mixture of right- and left-handed double helices composed by [SnI] and [P] helices. SnIP nanorods <20 nm in diameter can be accessed mechanically and chemically within minutes.

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The first lead polyphosphide PbP7 was synthesized from the elements in a lead flux through a low-temperature route. The PbP7 structure was determined from single crystal X-ray diffractometer data: new type, P21/c, a = 970.70(11), b = 673.34(10), c = 1243.89(18) pm, β = 122.55(1)°, wR = 0.0488, 2022 F(2) values and 74 variables. PbP7 exhibits a pronounced three-dimensional phosphorus substructure that derives from the modification of black phosphorus: rows of trans-edge-sharing P6 hexagons in chair conformation are condensed via P bridges. Two of the seven crystallographically independent phosphorus atoms have two and five of them have three P neighbours, leading to an electron-precise Zintl-like description Pb(2+)P(-)P(-)P(0)P(0)P(0)P(0)P(0). The P-P distances lie in a small range of 219 to 225 pm, indicating P-P single bond character. The lead atoms fill large cages left by the phosphide substructure. Each lead atom is coordinated to six P atoms (283-333 pm Pb-P) in the form of a half-shell (capped pentagon). The opposite side claims the space for the lead lone pair (L) leading to very long Pb-Pb distances of 473 pm between adjacent P6PbL pairs. Consistent with the crystal structure, (31)P magic-angle spinning (MAS) NMR spectra show seven distinct signal components with equal peak areas.

AgP15 was synthesized from the elements via a short-way transport reaction following the mineralizer concept. The needle-shaped crystals were characterized by single-crystal and powder X-ray diffraction. It crystallizes triclinically in space group P1̅ with cell parameters of a = 6.937(1) Å, b = 9.000(1) Å, c = 11.103(2) Å, α = 99.95(1)°, β = 99.61(1)°, and γ = 105.980(9)°. AgP15 exhibits a tubular phosphorus substructure related but neither isotypic nor isostructural to the alkaline phosphides MP15 (M = Li-Rb). The thermal properties, electronic structure, and experimental band gap of this new semiconductor have been determined. Finally, Raman spectra of AgP15 and selected alkaline-metal polyphosphides MP15 have been measured and interpreted. AgP15 represents the first transition-metal representative of this class of materials.

The phosphides REIr(2)P(2) (RE = La-Nd, Sm) and arsenides REIr(2)As(2) (RE = La-Nd) were synthesized by a ceramic route via precursor compounds REIr(2) with phosphorus and arsenic, respectively. Well-shaped single crystals were obtained from lead and bismuth fluxes, respectively. The nine pnictides crystallize with the tetragonal CaBe(2)Ge(2) type structure, space group P4/nmm. The structures of CeIr(2)P(2), SmIr(2)P(2), LaIr(2)As(2) and CeIr(2)As(2) were refined from single crystal X-ray diffractometer data. The structures are composed of three-dimensional [Ir(2)P(2)] and [Ir(2)As(2)] networks in which the rare earth atoms fill cavities of coordination number 16 (8 P + 8 Ir). The phosphorus and arsenic atoms have tetrahedral and square pyramidal iridium coordination. Temperature dependent magnetic susceptibility measurements show intermediate cerium valence for CeIr(2)P(2). The rare-earth and phosphorus local environments in LaIr(2)P(2) are characterized further by (139)La and (31)P single and double resonance solid state nuclear magnetic resonance (NMR) spectroscopy. Strong (31)P Knight shifts and extremely short spin-lattice relaxation times indicate that the bonding character of the phosphide species is strongly metallic. The two crystallographically distinct phosphorus sites are well-resolved in the (31)P magic-angle spinning (MAS) spectrum and also differ significantly with respect to their effective magnetic shielding anisotropies. Unambiguous site assignments are accomplished on the basis of homonuclear (31)P-(31)P magnetic dipole-dipole interactions, which can be measured in a site-resolved fashion in this compound using static (31)P spin echo decay spectroscopy. The highly symmetric La environment in LaIr(2)P(2) is characterized by a sharp (139)La MAS-NMR spectrum, revealing rather weak nuclear electric quadrupole coupling. Furthermore, a second local environment is detected, which is characterized by stronger quadrupolar coupling and similar dipolar coupling strength with (31)P as the regular site, according to (139)La{(31)P} rotational echo double resonance (REDOR) NMR results. On the basis of these data we attribute this site to a La species next to a phosphorus vacancy. From the signal area of this resonance we deduce a composition LaIr(2)P(1.90).

Nanoparticles of Bi3 Ir, obtained from a microwave-assisted polyol process, activate molecular oxygen from air at room temperature and reversibly intercalate it as oxide ions. The closely related structures of Bi3 Ir and Bi3 IrOx (x≤2) were investigated by X-ray diffraction, electron microscopy, and quantum-chemical modeling. In the topochemically formed metallic suboxide, the intermetallic building units are fully preserved. Time- and temperature-dependent monitoring of the oxygen uptake in an oxygen-filled chamber shows that the activation energy for oxide diffusion (84 meV) is one order of magnitude smaller than that in any known material. Bi3 IrOx is the first metallic oxide ion conductor and also the first that operates at room temperature.

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The lanthanum-rich antimonide La2NiSb was synthesized by annealing a cold-pressed pellet of the elements in a sealed silica glas tube at 1120 K. La2NiSb was characterized by powder and single-crystal X-ray diffraction: ordered Bi3Ni type, Pnma, Z =4, a=825.6(3), b=452.2(2), c=1195.5(4) pm, wR=0.0695, 856 F2 values, 26 variables. The nickel atoms form infinite zigzag chains (259 pm Ni-Ni) with trigonal-prismatic lanthanum coordination for each nickel atom. The antimony atoms cap the rectangular faces of the lanthanum prisms (336 pm La-Sb) and thereby coordinate also the nickel atoms (271 pm Ni-Sb). These rods run parallel to the b axis and form a herringbone pattern, similar to the FeB-type structure of GdNi. Although metallic conductivity is expected for La2NiSb from DFT-based band structure calculations, the real-space bonding analysis shows prominent localization of electrons on antimonide anions and positively charged lanthanum cations. The chain substructure is strongly bonded by polar covalent Ni-Sb and multicenter Ni-Ni interactions. The nickel atoms, which are involved in multicenter bonding with adjacent nickel and lanthanum atoms, provide a conductivity pathway along the prismatic strands. 121Sb Mössbauer spectroscopic data at 78 K show a single signal at an isomer shift of -7.62(3)mms-1, supporting the antimonide character. La2NiSb shows weak paramagnetism with a susceptibility of 2.5 x 10-3 emu mol-1 at room temperature.