Crystal structures and characterization of cobalt(II), manganese(II), and zinc(II) complexes of 2-(bis-(2-benzimidazolylmethyl)amino)ethanol.

Cobalt(II), manganese(II), and zinc(II) complexes with the tripodal ligand, 2-[Bis(2-benzimidazolylmethyl)amino]ethanol, bbt, were prepared and characterized by infrared and electronic spectra, magnetism, and conductivities. Their crystal structures were determined by X-ray diffraction method. Crystal data: [Co(bbt)(NCS)<SUB>2</SUB>] (<B>1</B>), space group P2<SUB>1</SUB>2<SUB>1</SUB>2<SUB>1</SUB>(orthorhombic), <I>a</I>=12.881(1), <I>b</I>=17.970(2), <I>c</I>=9.076(1) Å; [Mn(bbt)(NCS)<SUB>2</SUB>](<B>2</B>), space group P2<SUB>1</SUB>2<SUB>1</SUB>2<SUB>1</SUB>(orthorhombic), <I>a</I>=18.179(2), <I>b</I>=13.073(2), <I>c</I>=9.097(2) Å; [Zn(bbt)(NCS)<SUB>2</SUB>](<B>3</B>), space group P2<SUB>1</SUB>/ a(monoclinic), <I>a</I>=15.421(4), <I>b</I>=14.803(4), <I>c</I>=10.589(3) Å, β=115.81(2)°. The final <I>R</I> values are 0.044 (<B>1</B>), 0.054 (<B>2</B>), and 0.079 (<B>3</B>), for non-hydrogen atoms. The coordination geometries of <B>1</B> and <B>2</B> can be described as a distorted octahedron. In <B>3</B>, the alcoholic oxygen of bbt is not in coordination, hence the zinc ion is five-coordinated forming a highly distorted trigonal bipyramid. In all the complexes, thiocyanate ions coordinate in <I>cis</I> form with the nitrogen atoms. The magnetic measurements revealed that <B>1</B> and <B>2</B> are high spin complexes.