The first quaternary lanthanide(III) nitride iodides: NaM₄N₂I₇ (M=La–Nd)

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• 作者：Christian M. Schurz ; Thomas Schleid
• 关键词：Trans-edge linked [NM₄]⁹⁺ tetrahedra ; Isolated [NaI₆]^5– ; octahedra ; Crystal structures ; IR spectra
• 刊名：Journal of Solid State Chemistry
• 出版年：2010
• 出版时间：October 2010
• 年：2010
• 卷：183
• 期：10
• 页码：2253-2260
• 全文大小：1180 K

文摘

In attempts to synthesize lanthanide(III) nitride iodides with the formula M₂NI₃ (M=La–Nd), moisture-sensitive single crystals of the first quaternary sodium lanthanide(III) nitride iodides NaM₄N₂I₇ (orthorhombic, Pna2₁; Z=4; a=1391–1401, b=1086–1094, c=1186–1211 pm) could be obtained. The dominating structural features are chains of trans-edge linked [NM₄]⁹⁺ tetrahedra, which run parallel to the polar 2₁-axis [001]. Between the chains, direct bonding via special iodide anions generates cages, in which isolated [NaI₆]^5– octahedra are embedded. The IR spectrum of NaLa₄N₂I₇ recorded from 100 to 1000 cm^–1 shows main bands at υ=337, 373 and 489 cm^–1. With decreasing radii of the lanthanide trications these bands, which can be assigned as an influence of the vibrations of the condensed [NM₄]⁹⁺ tetrahedra, are shifted toward higher frequencies for the NaM₄N₂I₇ series (M=La–Nd), following the lanthanide contraction.