Compartmental ligands. Part 8. Metal complexes of ligands derived from 2,3-dihydro-2-hydroxy-4H-1-benzopyran-4-one and α,ω-diamines: crystal and molecular structures of two mononuclear nickel(II) and one mononuclear copper(II) complexes

Abstract

Compartmental Schiff-base ligands have been prepared from 2,3-dihydro-2-hydroxy-4H-1-benzopyran-4-one and alkane-α,ω-diamines. Mononuclear copper(II), nickel(II), cobalt(II), and dioxouranium(VI) complexes have been prepared and the site occupancy established: the nickel(II) and cobalt(II) are N₂O₂, the dioxouranium(VI) is O₂O₂, and positional isomers are available for copper(II). Homobinuclear copper(II), nickel(II), and oxovanadium(IV) complexes were prepared, as were heterobinuclear complexes containing copper(II) and dioxouranium(VI), and nickel(II) and dioxouranium(VI). Three-dimensional X-ray crystal structure analyses have been carried out on {3,3′-(ethane-1,2-diyl-di-imino)bis[1-(o-hydroxyphenyl)-prop-2-enonato]-(N,N′,O¹O¹′)}nickel(II), (8a; M = Ni), {3,3′-(propane-1,3-diyldi-imino)bis[1-(o-hydroxyphenyl)prop-2-enonato](N,N′,O¹,O¹′)}copper(II), (8b; M = Cu), and the related complex {3,3′-(ethane-1,2-diyldi-imino)bis[1-(o-hydroxyphenyl)but-2-enonato](N,N′,O¹,O¹′)}nickel(II), (10). Two crystallographically independent molecules were found for (10). Complex (8a; M = Ni) has Z= 8 in a monoclinic cell with space group C2/c(no. 15, C⁶_2h), and dimensions a= 23.373(13), b= 7.800(1), c= 20.819(6)Å, β= 110.14(4)°; R= 0.1341 for 603 reflections. Complex (8b; M = Cu) has Z= 8 in a monoclinic cell with space group C2/c(no. 15, C⁶_2h) and dimensions a= 23.098(18), b= 9.525(5), c= 18.046(8)Å, β= 104.15(5)°; R= 0.1063 for 891 reflections. Complex (10) has Z= 16 in a monoclinic cell with space group B2₁/c(a non-standard setting of P2₁/c, no. 14, C⁵_2h) and dimensions a= 26.11(4), b= 7.797(4), c= 38.42(6)Å, β= 93.656(8)°; R= 0.0376 for 4 344 reflections.