Transition metal compounds of a chelating imidazole-thioether-amine ligand. Crystal and molecular structures of (4-(5-methyl-4-imidazolyl)-1-amino-3-thiabutane)di(chloro)copper(II), bis(4-(5-methyl-4-imidazolyl)-1-amino-3-thiabutane)copper(II) dichloride dihydrate, and bis(4-(5-methyl-4-imidazolyl)- 1-amino-3-thiabutane)cobalt (III) tris(tetrafluoroborate)

Abstract

The synthesis and characterization of a series of monomeric transition metal coordination compounds with the ligand 4-(5-methyl-4-imidazolyl)-1-amino-3-thiabutane (abbreviated memia) are described, viz. [M(memia)Cl 2](H 2O) n, with MCo, Ni, Cu; [M(memia) 2]X 2(H 2O) n , with MNi, Cu and XCl, NO 3, BF 4; and [Co(memia) 2]X 3 with XNO 3, BF 4. Single crystals of [Cu(memia)Cl 2] ( A), [Cu(memia) 2]Cl 2(H 2O) 2 ( B) and [Co(memia) 2](BF 4) 3 ( C) were used in structure determinations. A crystallizes in the monoclinic space group P2 1/ n ( Z=4) and B and C crystallize in the monoclinic space group P2 1/ c ( Z=2 and 4, respectively). The cell dimensions for compound A are a=7.025(2), b=8.486(2), c=19.484(6) Å, β=98.07(3)°, V=1150 Å 3, D x=1.76 g cm −3. The cell dimensions for compound B are a=7.742(1), b=14.845(4), c=9.936(2) Å, β=104.80(2)°, V=1104 Å 3, D x=1.53 g cm −3. The cell dimensions for C are a=19.841(4), b=9.166(5), c=14.813(3) Å, β=99.71(2)°, V=2656 Å 3, D x=1.65 g cm −3. The structures were solved by heavy-atom techniques and refined by least-squares methods to residual R w values of 0.043 ( A), 0.048 ( B)and 0.079 ( C). The coordination geometry of the copper(II) ion in A is intermediate between square pyramidal and trigonal bipyramidal. The copper(II) ion is surrounded by an imidazole nitrogen (CuN=1.96 Å), an amine nitrogen (CuN=1.99 Å) and a thioether sulfur (CuS=2.43 Å) from the ligand and by two chloride anions (CuCl(1)= 2.55, CuCl(2)=2.28 Å). The coordination geometry of the metal ions in the bis(ligand) complexes B and C is distorted octahedral. The metal ions are coordinated by two imidazole nitrogens, two amine nitrogens and two thioether sulfurs. For compound B the imidazole nitrogens and the amine nitrogens are in the equatorial plane at 2.02 and 2.03 Å, respectively, and the thioether sulfurs are at the axial positions at rather large distances, e.g. 2.77 Å. For compound C the equatorial positions are also occupied by two imidazole nitrogens at 1.91 Å and two amine nitrogens at 1.99 Å. The thioether sulfur atoms are situated at the axial positions at 2.25 Å.