“…Incorporation of the unexplored linear N - tetradentate enpnen ligand in the synthesis of Cu(II)–Mo(IV) systems resulted in the formation of a trinuclear [Cu II (enpnen)] 2 [Mo IV (CN) 8 ]·6.75H 2 O molecule ( 1 ). Trinuclear cyanido-bridged Cu 2 Mo molecules are commonly observed among Cu(II)–Mo(IV) systems. ,,,,,,,− Such a structural arrangement is favored due to the charge compensation of two [Cu(L) n ] 2+ ions by [Mo(CN) 8 ] 4– anion. In all the assemblies, the coordination sphere of copper(II) is completed either by four nitrogen atoms of two terminal N - bidentate ligands ,,,,, or one terminal N - tetradentate ligand. ,,,, Analysis of local geometries of copper(II) centers (Supporting Information, Table S3) reveals that trigonal bipyramid geometry is exceptional among trinuclear systems and can be achieved mainly for tripodal ligands tris(2-aminoethyl)amine and tris(2-pyridylmethy)amine and bulky bidentate aromatic 2,2′-bipyridine. , In other cases copper(II) adopts intermediate geometry between square pyramid and vacant octahedron with a slight predominance of the first one.…”