ORGANO-COBALT(II) PHOSPHORANE IMINATO COMPLEXES WITH HETEROCUBANE STRUCTURES - CRYSTAL-STRUCTURES OF [COBR(NPR3)](4) WITH R = ME, ET, [CO(C-C-CME3)(NPME3)](4), AND [CO(C-C-SIME3)(NPET3)](4)

The phosphorane iminato complexes [CoBr(NPR3)](4), which are accessibl e by reaction of CoBr2 with the silylated phosphorane imines Me3SiNPR3 (R = Me, Et) in the melt at 180 degrees C and in the presence of KF, can be transformed into the alkynyl complexes [Co(C drop C-CMe3) (NPMe 3)](4) and [Co(C drop C-SiMe3)(NPEt3)](4) on obtaining the heterocuban e structures, when caused to react with the lithium organic reagents L iC drop C-CMe3 and LiC drop C-SiMe3 in THF at 0 degrees C. According t o the crystal structure analyses all four of the compounds form hetero cubane structures with only slightly distorted Co4N4 cubic structures.