The combination of lone-pair effects on Pb(2+) cations and the smaller electronegativity of I(-) anions into the pentaborate framework generates a phase-matchable material, Pb(2)B(5)O(9)I, with the largest powder SHG response among borates, about 13.5 times that of KDP (KH(2)PO(4)), and transparency over the near-UV to middle-IR region. DFT calculations on electronic structure and cutoff-energy-dependent SHG coefficients confirm these origins.

New noncentrosymmetric rare-earth metal gallium thioantimonates, Ln(4)GaSbS(9) were synthesized from stoichiometric element mixtures at 950 °C by high-temperature solid-state reactions. These compounds crystallize in orthorhombic space group Aba2 (no.41) with a = 13.799(3)-13.427(5) Å, b = 14.187(3)-13.756(5) Å, c = 14.323(3)-13.954(5) Å, V = 2804(2)-2577 (2) Å(3), and Z = 8 on going from Ln = Pr to Ho. The asymmetric building units, bimetallic polar (Sb(2)S(5)) units, and dimeric (GaS(4))(2) tetrahedra are in-phase aligned as an infinite single anionic chain of {[(Ga(2)S(6))(Sb(2)S(5))](10-)}(∞) that is further packed in a noncentrosymmetric pseudolayer motif perpendicular to the c axis. Three of the title compounds show large powder second harmonic generation (SHG) effects at 2.05 μm, and two of them also exhibit large transparency ranges (1.75 or 0.75 to 25 μm) in the middle-IR region. Significantly, the Sm-member exhibits the strongest SHG response among sulfides to date with intensity approximately 3.8 times that of the benchmark AgGaS(2). The band structures, indirect band gap nature, bonding strengths, and lone pair effects around Sb have also been studied by Vienna ab initio simulation package calculations.

Ready to direct: Crystalline selenidostannates were synthesized in imidazolium‐based ionic liquids with a small amount of hydrazine monohydrate as additive (see scheme). They are the first open‐framework chalcogenides structurally directed by imidazolium cations and are inaccessible by traditional methods.

Two new noncentrosymmetric quaternary sulfides, La(2)Ga(2)GeS(8) (1) and Eu(2)Ga(2)GeS(7) (2), have been synthesized by high-temperature solid-state reactions. The structure change on going from 1 to 2 to the known Li(2)Ga(2)GeS(6) (3) nicely shows that the reduced cation charge-compensation requirement causes a decrease in the number of terminal S atoms per formula, which is a key to determining the connectivity of the GaS(4) and GeS(4) building units. Powder sample 2 exhibits a strong second-harmonic-generation (SHG) response of about 1.6 times the benchmark AgGaS(2) at 2.05 μm laser radiation, a non type I phase-matchable behavior, and a comparable transparency region. The SHG intensities of these compounds originate from the electronic transitions from S 3p states to La/Eu/Li-S, Ga-S, and Ge-S antibonding states according to Vienna ab initio simulation package studies.

Two new quaternary chalcogenides, La(4)FeSb(2)S(10) and La(4)FeSb(2)Se(10), have been synthesized from the stoichiometric mixture of elements by solid-state reactions at 1100 degrees C. The compounds crystallize in the orthorhombic space group Pbcm with a = 15.066(4) A, b = 7.590(2) A, c = 13.341(4) A, and Z = 4 and a = 15.596(5) A, b = 7.869(2) A, c = 13.960(4) A, and Z = 4, respectively. These structures represent an unique three-dimensional network, in which SbQ(3) trigonal pyramids (Sb-S < 2.60 A, Sb-Se < 2.80 A) are connected via a relatively weak Sb-Q bond (Sb-S approximately 2.90 A, Sb-Se approximately 3.00 A) in a novel teeter-totter (SbQ(4))(n) chain motif. The theoretical studies confirm the Sb-Q bonding interactions within such teeter-totter chains. Their optical band gaps are measured to be 1.00 and 0.85 eV. At room temperature, their electrical conductivities are about 10(-4) S/cm. Both compounds display antiferromagnetic interactions between Fe centers, and their effective magnetic moments are 5.25 and 6.17 micro(B), respectively.

Two types of novel ordered chalcogenids Cs[Lu 7 Q 11 ] (Q = S, Se) and (ClCs 6 )[RE 21 Q 34 ] (RE = Dy, Ho; Q = S, Se, Te) were discovered by high-temperature solid state reactions. The structures were characterized by single-crystal X-ray diffraction data. Cs[Lu 7 Q 11 ] crystallize in the orthorhombic Cmca (no. 64) with a = 15.228(4)−15.849(7) Å, b = 13.357(3)−13.858(6) Å, c = 18.777(5)−19.509(8) Å, and Z = 8. (ClCs 6 )[RE 21 Q 34 ] crystallize in the monoclinic C2/m (no. 12) with a = 17.127(2)−18.868(2) Å, b = 19.489(2)− 21.578(9) Å, c = 12.988(9)−14.356(2) Å, β = 128.604(2)−128.738( 4)°, and Z = 2. Both types of compounds feature 3D RE−Q network structures that embed with dual tricapped cubes Cs 2 @Se 18 in the former or unprecedented matryoshka nesting doll structure cavities of (ClCs 6 )@Se 32 in the latter. The band gap, band structure, as well as a structure change trend of the majority of A/RE/Q compounds are presented.

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On the basis of density functional theory calculations, we study the electronic and magnetic properties of an iron phthalocyanine (FePc) nanosheet (FePcNST) and its derivatives, nanoribbons (FePcNRs) and nanotubes (FePcNTs). The GGA+U+SOC calculations reveal that the interesting in-plane magnetic anisotropy comes from unquenched in-plane orbital moments for FePcNST. The calculations indicate that the most stable antiferromagnetic (AFM) ordering for FePcNRs is G-type AFM, which is independent of the ribbon width. In addition, FePcNTs with radii larger than 10 Å are thermodynamically and thermally stable and can be rolled up from the FePcNST with only several millielectronvolts energy cost. Interestingly, the most stable AFM types of FePcNTs highly depend on the number of Fe ions (odd or even) on the circumference. These results may shed useful light on further experimental and theoretical studies on the organometallic nanosheet and its one-dimensional derivatives.