Abstract
Isometric black-reflecting crystals of Li3Sr3Ni4N4 (orthorhombic, Immm;
a = 401.1(1) pm, b = 708.8(3) pm, c = 1663.0(8) pm; Z = 2) were obtained
by wall-reaction of Li4SrN2 in closed nickel tubes (heating rate
50-degrees-C/h; reaction at 800-degrees-C for 20 h; cooling rate
10-degrees-C/h). The crystal structure contains infinity 1 [NiN]-chains
(Ni-N: 177.3(1) and 177.8(1) pm) which run parallel to the [010]
direction. Lithium and strontium are arranged in planes (010)
perpendicular to the [NiN]-chains and interconnect the chains via the
nitrogen atoms. Lithium is in a two-fold (linear; Li-N: 200.7(1) pm and
200.4(7) pm), strontium is in three- and four-fold (distorted trigonal-
and square-planar) N-coordination (Sr-N: 264.5(5) pm, 268.0(7) pm and
277.6(6) pm, resp.). Nitrogen is in an octahedral surrounding by Ni, Li
and Sr; the coordination-octahedra NNi2Sr4 and NNi2Li3Sr are condensed
by sharing common edges and apices. The three-dimensional framework
contains one-dimensional fragments of the (inverse) octahedral
structures of the ReO3 and Rutile structure types.
