138980-92-4Relevant academic research and scientific papers
Synthesis, Characterization and Crystal Structure of trans-2)pyridine-κN>chlorobis(trimethylphosphine)ruthenium(II) Perchlorate: Evidence for Meridional Steric Crowding
Bessel, Carol A.,See, Ronald F.,Jameson, Donald L.,Churchill, Melvyn Rowen,Takeuchi, Kenneth J.
, p. 2801 - 2806 (1991)
The synthesis, characterization, and crystal structure of trans-ClO4 are reported.The complex crystallizes in the non-centrosymmetric trigonal space group P3,21 (no. 152) with a = 14.158(2), c = 14.493(3) Angstroem, and Z = 3.Both the RuII-containing cation and the perchlorate anion (which is disordered) lie on a crystallographic two-fold axis.This represents the first structural characterization of a transition-metal complex which utilizes a member of the family of bis(pyrazolyl)pyridine ligands.In addition, the crystal structure yields evidence that the ligand L may be sterically more suitable for co-ordination to a ruthenium(II) centre than the analogous diphenyl-substituted terpyridine ligand, dpt (6,6''-diphenyl-2,2':6'2''-terpyridine).For both tridentate ligands, the donor nitrogen atoms take up three meridional sites and the phenyl substitutents are directed toward the fourth equatorial co-ordination site; however, due to the large distance between the two phenyl arms of L (relative to the dpt), the former ligand can be utilized in synthesizing the present ruthenium(II) complex whereas the analogous dpt complex cannot readily be prepared.
Synthesis and Characterization of Ruthenium Complexes which utilize a New Family of Terdentate Ligands based upon 2,6-Bis(pyrazol-1-yl)pyridine
Bessel, Carol A.,See, Ronald F.,Jameson, Donald L.,Churchill, Melvyn Rowen,Takeuchi, Kenneth J.
, p. 1563 - 1576 (2007/10/02)
To demonstrate the synthetic utility of a new family of terdentate ligands based on 2,6-bis(pyrazol-1-yl)pyridine (bpp), reaction conditions were developed to generate a variety of (1+) complexes .These complexes were characterized by elemental analyis, 1H and 13C NMR, infrared and UV/VIS spectroscopies, cyclic voltammetry, and single-crystal X-ray diffraction studies.The substituents of the terdentate bpp ligands sterically affected the Ru-N(pyrazole) bond lengths, the displacement of the nitrogen atoms of the nitro ligands from the RuL plane, and the twisting of the N-O vectors of the nitro ligand from that plane.Also the substituents affected the potentials and peak-current ratios of the RuIII-RuII couples.The log (ipc/ipa) values (ipc = cathodic peak current, ipa = anodic peak current) are linearly correlated with the steric size of the substituents as estimated by Tolman's cone angles and with the distance of the nitro ligand out of the RuL plane.A linear correlation was also found between the differences in infrared absorbances due to the N-O symmetric and asymmetric stretches and the ratio of the N-O bond distances observed from the four crystal structures.
