Two new complex main-group metal carbides were synthesized from reactions of indium, carbon, and a metal hydride in metal flux mixtures of an alkaline earth (AE = Ca, Ba) and lithium. Ca(12)InC(13-x) and Ba(12)InC(18)H(4) both crystallize in cubic space group Im3̅ [a = 9.6055(8) and 11.1447(7) Å, respectively]. Their related structures are both built on a body-centered-cubic array of icosahedral clusters comprised of an indium atom and 12 surrounding alkaline-earth cations; these clusters are connected by bridging monatomic anions (either H(-) or C(4-)) and allenylide anions, C(3)(4-). The allenylide anions were characterized by Raman spectroscopy and hydrolysis studies. Density of states and crystal orbital Hamilton population calculations confirm that both compounds are metallic.

Reactions of indium and silicon with lithium nitride in Ca/Li flux produce two new nitridosilicates: CaInSiN (orthorhombic, Ibam; a = 12.904(1) Å, b = 9.688(1) Å, c = 10.899(1) Å, Z = 4) and CaSiNH (monoclinic, C2/c; a = 5.236(1) Å, b = 10.461(3) Å, c = 16.389(4) Å, β = 91.182(4)°, Z = 8). CaInSiN features isolated [SiN] units and indium dimers surrounded by calcium atoms. CaSiNH features infinite chains of corner-sharing SiN tetrahedra and distorted edge-sharing H@Ca octahedra. Optical properties and band structure calculations indicate that CaInSiN is a void metal with calcium and indium states at the Fermi level and CaSiNH is a semiconductor with a band gap of 3.1 eV.

Two new tellurium-containing nitrides were grown from reactions in molten calcium and lithium. The compound Ca6Te3N2 crystallizes in space group R3̅c (a = 12.000(3)Å, c = 13.147(4)Å; Z = 6); its structure is an anti-type of rinneite (K3NaFeCl6) and 2H perovskite related oxides such as Sr3Co2O6. The compound Ca6(LixFe1-x)Te2N3 where x ≈ 0.48 forms in space group P42/m (a = 8.718(3)Å, c = 6.719(2)Å; Z = 2) with a new stuffed anti-type variant of the Tl3BiCl6 structure. Band structure calculations and easily observable red/green dichroic behavior indicate that Ca6Te3N2 is a highly anisotropic direct band gap semiconductor (Eg = 2.5 eV). Ca6(LixFe1-x)Te2N3 features isolated linear N-Fe-N units with iron in the rare Fe(1+) state. The magnetic behavior of the iron site was characterized by magnetic susceptibility measurements, which indicate a very high magnetic moment (5.16μB) likely due to a high degree of spin-orbit coupling. Inherent disorder at the Fe/Li mixed site frustrates long-range communication between magnetic centers.

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