(OLi2Ca4)(3)[ReN4](4), a nitridorhenate(VI) oxide

Black single crystals of (OLi2Ca4)(3)[ReN4](4) were prepared from the eleme nts (molar ratio Li:Ca:Re = 6:1:1) by reaction with molecular nitrogen at 9 00 degreesC; oxygen content results from a leak in the gas supply. The nitr idorhenal(VI)-oxide is an isotype of (OLi2Ca4)(3)[MN4](4) (M = Mo-VI, W-VI) . These compounds are obtained under similar reaction conditions in the pre sence of small amounts of oxygen containing impurities (Li-/Ga-hydroxides). The crystal structure of (OLi2Ca4)3[ReN4]4 was determined by single crysta l methods (cubic; 143d (#220); a=1315.X8(9) pm; Z=4) and can be derived fro m the Th3P4 type structure by hierarchical replacements: Th <(<boolean AND> )double under bar> (OLi2Ca4)(8+)-tetragonal bipyramids and P <(<boolean AND >)double under bar> [(ReN4)-N-VI] "-tetrahedra.