| Popis: |
A new nitride, Ba 9 Ge 3 N 10 , was obtained as single crystals from constituent elements in molten Na. It crystallizes in space group R-3c (No. 167) with a = 7.9399(2) A, c = 17.282(1) A, and Z = 2. It contains the first example of isolated nitridometallate anions of GeN 3 5- in perfect planar triangular shape. Ge-N bond length is 1.786(8) A, which is significantly shorter than any known Ge-N bonds, ranging from 1.84 A to 1.95 A. Valence bond model suggests partial multiple bonding character of the Ge-N bond, which is the first example of such bonding configuration for Ge-N bond. N-centered polyhedral perspective suggests the structure of Ba 9 Ge 3 N 10 can be conceived as the cationic framework of [Ba 9 Ge 3 N9] 3+ , whose 1/3 of the octahedral interstitial sites are occupied by N 3- anions. |
