Neutral Four-coordinate Tetrahedral Manganese(II) Species Involving Coordinated Chloro- and Thiocyanato-Groups

Abstract

Although high-spin and some low-spin octahedrally coordinated anionic and neutral complexes of manganese(I1) are common, tetrahedral coordination manganese(11) is mainly exhibited' in anionic species [MnX4l2-, X =CI, Br, CN, NCO, NCS or NCSe. Whereas manganese(I1) bromide is known to form neutral four-coordinated structures1 MnL, Br, L =Me, NO, C5H5N0, Ph, PO or Ph3As0, four-coordinated tetrahedral manganese(II) complexes as neutral species involving coordinated chloro- and thiocyanato-groups, MnL2X2 (L =a monodentate ligand, and X =C1 or NCS) are rather unknown. We report the isolation of 1 : 2 manganese(I1) chloride and thiocyanate complexes with 4-cyanopyridine N-oxide (4-CPO) which are shown from room temperature magnetic moments, electronic spectral, ligand field parameters and i.r. spectral studies down to 200 cm-' as neutral species exhibiting four-coordinated high-spin, monomeric tetrahedral environments around manganese(II) containing coordinated chloro- and thiocyanato- groups in the solid state.