A new class of biomimetically relevant ''scorpionate'' ligands .1. The (2-hydroxyphenyl)bis(pyrazolyl)methanes: Synthesis and structural characterization of some cobalt(II) complexes

The syntheses of a new class of potentially biomimetic, tripodal, mixed functionality ligands, (2-hydroxyphenyl)bis(pyrazolyl)methane(L1), (2-hydroxyphenyl)bis(3,5-dimethylpyrazolyl)methane(L2), and (2-hydroxyphenyl)bis(3-isopropylpyrazolyl)methane(L3), are described. These ligands have been used to prepare the cobalt(II) complexes [Co(L1)(2)]. 2.5MeOH . 1.5H(2)O, 1 . 2.5MeOH . 1.5H(2)O; [Co(L2)(2)]. 0.5H(2)O, 2 . 0.5H(2)O; [Co(L3)Cl-2], 3; and [Co-3(mu(3)-OH)(2)(mu-L3)(2)(L3)(H2O)]BF4, 4. X-ray structural analysis of 1-4 gave the following structural parameters: 1, C30H34N8CoO6, triclinic, a = 8.286(2) Angstrom, b = 10.053(3) Angstrom, c = 10.562(2) Angstrom, alpha = 109.66(2)degrees, beta = 96.57(1)degrees, gamma = 91.11(3)degrees, space group <P(1)over bar>, Z = 1; 2, C38H38N8CoO6, triclinic, a = 8.746(5) Angstrom, b = 10.900(5) Angstrom, c = 11.399(8) Angstrom, alpha = 70.82(4)degrees, beta = 75.13(5)degrees, gamma = 81.46(4)degrees, space group <P(1)over bar>, Z = 1; 3, C20H26N4Cl4CoO, monoclinic, a = 10.934(2) Angstrom, b = 12.404(2) Angstrom, c = 19.267(3) Angstrom, beta = 98.33(1)degrees, space group P2(1)/n, Z = 4; 4, C58H70N12BCo3F4O9, monoclinic, a = 14.798(5) Angstrom, b = 23.657(8) Angstrom, c = 20.614(7) Angstrom, beta = 97.75(2)degrees, space group P2(1)/n, Z = 4.