Scandium nitride chlorides

The borderline between cluster and valence compounds is clearly crossed with the scandium nitride chlorides which are unambiguously cluster compounds. Scandium shows here its difference in behavior, with compounds such as SC4CI6N, SC7CI12N (Hwu and Corbett 1986) or ScsClgN (Hwu et al. 1987), where nitrogen is an interstitial element. 

Other Binary Compounds.—Scandium nitride and zirconium and titanium carbide do not conform with the theoretical radii. It is possible that these crystals do not consist essentially of Sc+3, N 3, Ti+4, Zr+4 and C-4 ions, especially since zirconium and titanium nitride, ZrN and TiN, also form crystals with the sodium chloride structure but possibly also the discrepancy can be attributed to deformation of the anions, which have very high mole refraction values. 

Hwu, S.-J., Ziebarth, R. P., von Winbush, S., Ford, J. E. Corbett, J. D. (1986). Synthesis and Structure of Double-Metal-Layered Scandium, Yttrium, and Zirconium Chloride Carbides and Nitrides, M2CI2C and M2CI2N, Inorg. Chem. 25, 283-287. 

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