Lewis-base adducts of Group 1B metal(I) compounds. Part 19. Crystal structures of bis(1,10-phenanthroline)copper(I) perchlorate and dibromocuprate(I)

Abstract

The crystal structures of the title compounds [Cu(phen)₂][ClO₄](1) and [Cu(phen)₂][CuBr₂](2)(phen = 1,10-phenanthroline) have been established by single-crystal X-ray diffraction methods at 295 K. Crystals of (1) are monoclinic, P2/c, a= 10.037(3), b= 14.518(6), c= 7.672(3)Åβ= 97.82(3)°, Z= 2. R was 0.056 for 709 independent ‘observed’ reflections. Crystals of (2) are monoclinic, C2/c, a= 17.206(4), b= 13.365(2), c= 10.920(3)Å, β= 115.43(2)°, Z= 4. R was 0.048 for 1 091 independent ‘observed’ reflections. Surprisingly, complex (2) is not a di-µ-bromo- bridged dimer, [(phen)CuBr₂Cu(phen)], but ionic [Cu(phen)₂][CuBr₂]. In both (1) and (2), the [Cu(phen)₂]⁺ cation has crystallographic 2 symmetry; in (1), the 2 axis passes through the ligands so that the overall symmetry is close to 222, but in (2) it passes between the ligands, so that the cation geometry is very far removed from 222 symmetry. In (1), Cu–N are 2.045(8), 2.053(9)Å; in (2), 2.006(8) and 2.071(5)Å. The linear anion in (2) has Cu–Br 2.209(2) and 2.223(2)Å. The dihedral angles for each compound differ significantly, being 49.9° for (1) and 76.8° for (2), the former being the lowest value yet observed for a copper(I) cation with two bidentate ligands.