Isolation and characterization of chloro(ethyl)dimethylglyoximatodimethylglyoximecobalt(III) hydrate. A protonated cobaloxime

Crumbliss, Alvin L.; Bowman, Jennifer; Gaus, Paul L.; McPhail, Andrew T.

doi:10.1039/c39730000415

Cited by 20 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the reactions of the bis(dimethylglyoximato) complexes this behavior was ascribed5 to protonation of the chelate ring at the O-H-O position, an assignment which was confirmed later. 23 The kinetic data are consistent with a mechanism in which a similar rapid protonation equilibrium occurs (the site of protonation will be considered later), the rate-determining step being the reaction of Hg2+ with the unprotonated form of the methylcobalt complex, as shown in eq 3 and 4. According to this mechanism kb CH3Co(chelate)H20 + H+ •*=* [CH3Co(chelate H)H20]+…”

Section: Resultssupporting

confidence: 76%

Kinetic study of the transfer of methyl groups to mercury(II) from a series of methylcobalt(III)-chelate complexes

Espenson¹,

Bushey²,

CHMIELEWSKI³

1975

Inorg. Chem.

View full text Add to dashboard Cite

Kinetics studies of the electrophilic cleavage of the Co-C bond in a series of six CH3Co(chelate) H2O complexes by Hg2+ were carried out. The kinetic data support an electrophilic (Se2) mechanism, in that changes in electron density at the cobalt center which accompany the variation in chelate structure are transmitted to the transition state for the heterolytic cleavage of the C0-CH3 bond. The values of k/M™1 sec™1 at 25.0°and µ LO Min aqueous solution are as folows: saloph, (3.3 ± 0.3) X 104; salen, (2.6 ± 0.4) X 104; Measalen, (2.1 ± 0.1) X 104; (dmgH)2, 65 ± 2; dpnH, 1.77 ± 0.03; tim (at µ 1.60 M), (4.5 ± 0.5) X 10™4. For the first four members, the reaction rate is lowered by [H+], attributed to the protonation of the cobalt complex to an unreactive form; the equilibrium constants for these interactions were also evaluated.

show abstract

Section: Resultssupporting

confidence: 76%

Kinetic study of the transfer of methyl groups to mercury(II) from a series of methylcobalt(III)-chelate complexes

Espenson¹,

Bushey²,

CHMIELEWSKI³

1975

Inorg. Chem.

View full text Add to dashboard Cite

show abstract

“…For the case of 2,6-Me2pz (compounds 3 and 13), that distance is clearly shorter than in a cafena-(/t-pyrazine)bis(dimethylglyoximato)cobalt(II) compound (2.242 A).138 The Co-Cl bond distances, 2.228-2.253 A, agree well with those found in chloro(amine)cobaloximes,128,22 with an average value of 2.246 (15) A, significantly shorter than for chloro(phosphine)cobaloximes (average 2.288 (9) A for six compounds18) or a chloro(alkyl)cobaloxime (2.382 A). 23 All the organic ligands are planar. For compound 1, the geometry of that ligand is not significantly different from that of the free ligand.…”

Section: Resultsmentioning

confidence: 99%

Structure-NMR correlations in halo(ligand)bis(dioximato)cobalt(III) complexes

López¹,

Álvarez²,

Soláns³

et al. 1986

Inorg. Chem.

View full text Add to dashboard Cite

only an average structure was reported."The mechanism of a continuous spin transition in a solid state and the factors that determine electron-transfer rates are not yet understood although it is pointed out that a coupling between the electronic state and the vibrational modes of a molecule is important for spin transition in solution.*l In the system studied here, no evidence of first-order transition could be found. It may be important to image a intramolecular mechanism for rapid spin interconversion.Registry No. Hacpa, 28484-27-7; [Fe(acpa),]PF6, 90790-59-3; acetylacetone, 123-54-6; 2-(aminomethyl)pyridine, 373 1-51-9.Supplementary Material Available: Listings of programming data, thermal parameters, and mean-square displacement tensors of atoms (5 pages). Ordering information is given on any current masthead page. (21) Sutin, N. Arc. Chem. Res. 1982, 15, 275. A synthetic scheme leading to chloro(iigand)bis(dimethylglyoximato)-and chloro(ligand)bis(diphenylglyoximato)cobaIt(III)complexes in good yields is reported for the cases where the ligand is a nitrogenated aromatic base. Substitution reactions of the axial chloro ligand lead to the cyano ligand derivatives. Single-crystal X-ray diffraction and NMR spectroscopic studies were carried out to characterize the above-mentioned complexes. Crystal structures of the following compounds are reported: [Co-Chem. 1974, 13, 1564. Hill, 0. A,; Morallee, K. G. J . Chem. SOC. A 1969, 554. Bid-Charreton, C.; Alain, L.; Gaudemer, A. Bull. SOC. Chim. Fr. 1972, 861. Kargol, J. A.; Crecely, R. W.; Burmeister, J. L.; Toscano, P. J.; Marzilli, L. G. Inorg. Chim.

show abstract

“…Ignoring for the moment any difference between the phosphine and pyridine axial bases on the cobaloxime, the equilibrium constant for the reaction 2HCo(dmgH)2B = H2 + 2Co(dmgH)2B (18) can be estimated from the quotient of forward and reverse rate constants, using kf/2 determined in the present work for k\% and Simándi's value10 for k-is• Thus A]g = 1.7 X 104 M-1 s-1 /2.2 X 103 M-2 s-1 = 8 M. Even if the difference between B = py and P(/i-C4H9)3 is not negligible, these data are sufficient to show that hydridocobaloxime is considerably less stable (by ~4.3 kcal/mol Co-H) to dissociation to H2 and (Co11) than is HCo(CN)53-.…”

Section: Interpretation and Discussionmentioning

confidence: 99%