The Fe(III), Co(III), and V(III) Complexes of the “Heteroscorpionate” Ligand (2-Thiophenyl)bis(pyrazolyl)methane

Abstract

The synthesis and characterization of the tridentate “heteroscorpionate” mixed functionality ligand, (2-thiophenyl)bis(pyrazolyl)methane, L1, is reported. This ligand was used to synthesize the complexes, [Fe(L1)2][ClO4], [Co(L1)2][BPh4], and [V(L1)2][BPh4]. X-ray crystallographic analysis of the latter two complexes gave the following structural parameters: [V(L1)2][BPh4]·MeCN· i Pr2O, C58H57N9B1O1S2V1, monoclinic, a = 16.197(2) Å, b = 19.281(2) Å, c = 17.985(2) Å, β = 102.343(9)°, space group P21/c; [Co(L1)2][BPh4]·CH2Cl2, C51H42N8B1Cl2Co1S2, triclinic, a = 12.751(1) Å, b = 12.830(1) Å, c = 14.740(1) Å, α = 98.351(7)°, β = 98.122(6)°, γ = 97.023(8)°, space group P1̄. An example of the use of this new class of “heteroscorpionate” ligands for systematic comparisons of electronic properties of metal complexes with identical topology that vary only in the nature of one of the donor atoms is given.

New N , N , O , O functionalized heteroscorpionate ligands and related Zn(II) and Cd(II) derivatives

“…Other important variations can be effected by replacing the pyrazolyl with triazolyl [7], imidazolyl [8], and methimazolyl moieties [9] or by changing the substituents on the heterocyclic ring. In this research field several recent contributions are related to the polyfunctional bis(pyrazol-1-yl)methane systems, containing ethoxy [10] or thiolate [11] group to give a small degree of steric hindrance and considerable co-ordinative flexibility. In the last years we have initiated an investigation into the coordination chemistry of new ''scorpionate'' monoanionic ligands, N-, S-, and Odonor, towards early transition metal centres [12][13][14].…”

Ethylene polymerization catalyzed by group 4 metal complexes of tridentate heteroscorpionate ligands

“…The same methodology has been successfully extended to N,N,Sheteroscorpionate ligands bearing thiol groups using 1,1¢-sulfinyldipyrazoles as starting reagent [14]. This metal-catalyzed reaction is alternative to the typical nucleophilic displacement at saturated carbon of acetals or ketals with pyrazole or alkali metal pyrazolides [22].…”

“…Typical examples of tridentate monoanionic heteroscopionates are based on substituted bis(pyrazolyl)methane, HC(pz) 2 R¢ skeleton, where the R¢ group is e.g., a phenoxo [13], thiophenoxo [14], carboxylate [15] or dithiocarboxylate group [16] (Scheme 2). Higgs and Carrano investigated in detail the chemistry of biomimetic ligands of this type mimicking histidine and relevant biological functionalities: in the attempt to model the metalloprotein active sites, late and middle-late transition metal complexes of these poly-functional ligands were synthesized [17].…”

Cobalt(II) and Cobalt(III) Tri-tert-butoxysilanethiolates. Synthesis, Properties, Crystal and Molecular Structures of [Co{μ-SSi(OBut)3}{SSi(OBut)3}(NH3)]2 and [Co{SSi(OBut)3}2(NH3)4][SSi(OBut)3] Complexes

“…Some more stable cis(S) complexes of the type CoN 4 S 2 were obtained with such ligands as N,2-mercaptophenyl-2'-pyridinecarboxamide or N,2-mercapto-2-methylpropyl-2'-pyridinecarboxamide [31], bis(2-aminoethyl)sulfide [32], 1-thia-4,7-diazacyclononane [33], (2-thiophenyl)-bis(pyrazolyl)methane [34] and 2-((2-pyridylmethyl)amino)ethanethiolate [35]. The perchlorates of bis(phenylthiolato)bis(1,10-phenanthroline)cobalt(III) [36] and {tris(2-aminoethyl)-amine-N,N'N@}-bis(thioacetato)cobalt(III) [37] are also known.…”