Hexaphosphanylamine Ligands: 1,1,4,7,10,10‐Hexakis(diphenylphosphanyl)‐triethylenetetramine Complexes of Chromium, Molybdenum, and Tungsten

The oligophosphanylamine ligand 1,1,4,7,10,10‐hexakis(diphenylphosphanyl)triethylenetetramine ( 1 ) was obtained from the reaction of triethylenetetramine with six equivalents of chlorodiphenylphosphine in good yield. Ligand 1 was treated with three equivalents of [Cr(CO) 4 (MeCN) 2 ], [Mo(CO) 4 (nbd)] (nbd = norbornadiene), or [W(CO) 4 (MeCN) 2 ] in toluene to give the trinuclear tetracarbonyl complexes [{ M (CO) 4 } 3 {(PPh 2 ) 2 N(CH 2 ) 2 NPPh 2 (CH 2 ) 2 NPPh 2 (CH 2 ) 2 N(PPh 2 ) 2 }‐κ 6 P 1 , P 2 , P 3 , P 4 , P 5 , P 6 ] [ M = Cr ( 2 ), Mo ( 3 ), W ( 4 )]. Compounds 1 – 4 were fully characterized by NMR ( 1 H, 13 C, 31 P) and IR spectroscopy, elemental analysis and crystal structure determination ( 1 – 3 ). The molecular structures of 2 and 3 show the formation of tris‐chelate complexes with two M –P–N–P four‐membered rings and one M –P–N–CH 2 –CH 2 –N–P seven‐membered ring.