The coordination of small molecules by manganese(II) phosphine complexes. Part 13. The synthesis and characterisation of some novel manganese(II) complexes of tertiary butylisocyanide, MnX 2(CNBu t) (X = Cl, Br, I, NCS), and their reaction with tri(n-butyl)phosphine and molecular oxygen

Abstract

Novel tertiary butylisocyanide complexes of manganese(II) with unusual stoichiometry, MnX 2(CNBu t) (X = Cl, Br, I, NCS), have been prepared and characterised by magnetic susceptibility measurements and infrared and electron spin resonance spectroscopy. For X = Cl, Br, I the complexes have been assigned a polymeric structure similar to that found for MnI 2(PPhMe 2), whilst Mn(NCS) 2(CNBu t) is probably dimeric as the infrared spectrum exhibits bands assignable to both bridging and terminal thiocyanate groups. The MnX 2(CNBu t) show no ability to reversibly bind dioxygen, but in solution in tetrahydrofuran PBu 3 n displaces the isocyanide ligand and for X = Cl, Br, I these solutions absorb dioxygen in a 1:1 Mn:O 2 ratio.