Bdt Ligand Research Articles

A Mixed-Ligand Zinc(II) Complex Containing a Bridging Dithiolate Ligand

The mixed-ligand Zn II complex bis(μ-1,2-benzenedithiolato)-1κS,1:2κ 2 S'; 2κS, 1:2κ 2 S'-bis[(2,2'-bipyrimidine-κ 2 N 1 ,N 1' )zinc], [Zn 2 (C 6 H 4 S 2 ) 2 (C 8 H 6 N 4 ) 2 ], containing benzenedithiolate (bdt) and 2,2'-bipyrimidine (bpyrm) has been synthesized and found to have the dinuclear formulation [Zn(bdt)(bpyrm)] 2 . The dinuclear complex has crystallographically imposed 1 symmetry with severely distorted square-pyramidal coordination about the metal atoms. One S atom of the bdt ligand bridges the Zn atoms in an asymmetric fashion [Zn-S(1) 2.433 (3), Zn'-S(1) 2.475 (3) A] while the second S atom is bound in a terminal mode at a shorter distance [Zn-S(2) 2.303 (3) A]. The formation of a bdt-bridged rather than a bpyrm-bridged species may be favored by a significant π-stacking interaction between the phenyl ring of the bdt ligand and one ring of the bpyrm ligand.

Synthesis, characterization and X-ray crystal structure of the benzenedithiolatohafnium(IV) porphyrin complex

A novel hafnium porphyrin complex Hf(TPP)(bdt) (TPP=5,10,15,20-tetraphenylporphyrinate; bdt=benzenedithiolate) was synthesized and characterized. The X-ray crystal structure of the complex revealed a six-coordinate Hf atom surrounded by 4 N atoms of the porphyrin and 2 S atoms of the bdt ligand. The two sulfur atoms of the bdt are in an eclipsed position with respect to the two opposite pyrrole nitrogen atoms of the porphyrin. Crystal data for Hf(TPP)(bdt): tetragonal, P4 12 12, a= 12.471(2), c= 26.966(3) Å, V= 4038.2(7) Å 3, Z=4; R= 0.054 and R w= 0.060 for 2673 independent reflections with I>3σ( I).

Syntheses, structures and properties of tri-n-butylphosphine cobalt complexes containing o-benzenedithiolate ligands in unusual co-ordination modes

The complex [Co3(bdt)3(PBun3)3]1(H2bdt = benzene-1,2-dithiol) was obtained by the reaction of CoCl2, Na2bdt and PBun3 in 1:1:2 molar ratio in methanol. It crystallizes in triclinic space group P with a= 13.694(4), b= 18.460(4), c= 13.656(4)A, α= 100.69(2), β= 108.68(2), γ= 85.06(2)°, Z= 2, from 6366 reflections with I > 3σ(I), final R(R′)= 0.059 (0.066). The Co3 atoms form an isosceles triangle with rather short Co-Co bonds. The bdt ligands either bridge between two Co atoms or strongly chelate terminally to one Co atom and simultaneously bridge weakly to the others. Restricted air oxidation of 1 results in the isolation of [PHBun3][Co(bdt)2(PBun3)]2, which crystallizes in triclinic space group P with a= 10.800(3), b= 13.533(4), c= 15.342(2)A, α= 96.37(2), β= 108.57(2), γ= 97.02(2)°, Z= 2, from 3801 reflections with I > 3σ(I), R(R′)= 0.086 (0.088). The Co atom is in a square-pyramidal co-ordination environment with P in the axial position. The PBun3 group dissociates easily in dimethyl sulphoxide yielding paramagnetic [Co(bdt)2]–3 with square-planar cobalt co-ordination. Proton NMR data are discussed and cyclic voltammetry data reported.