Triphenylphosphineoxide nitrosyl complexes of molybdenum

Summary The tetramethylthiourea (TMTU) complexes of cobalt(II) and nickel(II) halides have been studied in the solid state by electronic, i.r. and far i.r. spectroscopy and magnetochemically. The tetrahedral Co(TMTU)₂X₂ (X = Cl, Br, 1) and Ni(TMTU)₂X₂ (X = Cl, Br) complexes have normal magnetic moments, electronic spectra and crystal field parameters; Ni₂ (TMTU)₃I₄ is diamagnetic. The cobalt complexes have normal (CoX) and (CoX) vibrational frequencies. Ni(TMTU)₂Cl₂ and Ni₂(TMTU)₃I₄ have (NiX) frequencies corresponding to long or bridging Ni-X bonds, while Ni(TMTU)₂Br₂ has normal (NiBr) frequencies for terminal Ni-Br bonds. The (MS) frequencies are similar to those of cobalt(II) and nickel(II) complexes of other thioureas.