Generation of a zinc and rhodium containing metallomacrocycle by rearrangement of a six-coordinate precursor complex

2020 ◽  
Vol 56 (3) ◽  
pp. 368-371 ◽  
Author(s):  
C. Groß ◽  
Y. Sun ◽  
T. Jost ◽  
T. Grimm ◽  
M. P. Klein ◽  
...  
Keyword(s):  
Precursor Complex

Two pentadentate N3,P2 ligands coordinate zinc(ii) by their N3 pocket.

On the Calculation of Transition State Activity Coefficient and Solvent Effects on Chemical Reactions

1998 ◽  
Vol 63 (12) ◽  
pp. 1969-1976 ◽  
Author(s):  
Alvaro Domínguez ◽  
Rafael Jimenez ◽  
Pilar López-Cornejo ◽  
Pilar Pérez ◽  
Francisco Sánchez
Keyword(s):  
Activity Coefficient ◽  
Transition State ◽  
Chemical Reactions ◽  
Solvent Effects ◽  
Transition State Theory ◽  
Reaction Medium ◽  
State Theory ◽  
Precursor Complex ◽  
State Activity ◽  
Classical Transition

Solvent effects, when the classical transition state theory (TST) holds, can be interpreted following the Brønsted equation. However, when calculating the activity coefficient of the transition state, γ# it is important to take into account that this coefficient is different from that of the precursor complex, γPC. The activity coefficient of the latter is, in fact, that calculated in classical treatments of salt and solvent effects. In this paper it is shown how the quotients γ#/γPC change when the reaction medium changes. Therefore, the conclusions taken on the basis of classical treatments may be erroneous.

Evidence for precursor complex formation in Cr2+-Co(III) reactions

1969 ◽  
Vol 91 (14) ◽  
pp. 3982-3983 ◽  
Author(s):  
Maria P. Liteplo ◽  
John F. Endicott
Keyword(s):  
Complex Formation ◽  
Precursor Complex

scholarly journals Syntheses and characterisation of chloro(h3-allyl) dicarbonylmolybdenum(II) complexes of chiral and achiral ditertiaryphosphines

2012 ◽  
Vol 10 (1) ◽  
pp. 165-171
Author(s):  
Joe Jesu Raj ◽  
Devendra Pathak ◽  
Pramesh Kapoor
Keyword(s):  
General Formula ◽  
Force Constant ◽  
Spectroscopic Techniques ◽  
Multinuclear Nmr ◽  
Precursor Complex ◽  
Elemental Analyses ◽  
Secular Equations

AbstractA series of the complexes of the general formula [ClMo(CO)2(η 3-C3H5)(P-P)], [where (P-P) = (m-CH3C6H4)2P(CH2)2PPh2 (m-t-dppe); cis-Ph2PCH=CHPPh2 (cis-diphos); Ph2PCH2CH2AsPh2 (arsaphos); Ph2P(CH2)4PPh2 (dppb); (±)-1,2-C6H4(PMePh)2 (rac-diphos); (2R,3R)Ph2PC*H(Me)C*H(Me)PPh2 (+)-chiraphos; (R,R)-Me2C(O)2{C*HCH2PPh2}2 (-)-diop] were synthesised by the reaction of the precursor complex [ClMo(CO)2(η 3-C3H5)(CH3CN)2] with the corresponding ditertiary phosphine in acetone. The complexes were isolated as yellow to orange air-stable solids and characterised by elemental analyses, FTIR and multinuclear NMR [1H, 31P{1H}] spectroscopic techniques. The carbonyl force constant values were calculated by Cotton and Kraihanzel approximate secular equations using ν C≡O stretching frequencies observed in the FTIR and these were found to be 14.30–14.59 mdyne 0-A−1 and 0.23–0.70 mdyne Å−1 for K1 and Ki respectively. Spectroscopic evidences have confirmed cis-octahedral structures for the synthesized complexes.

scholarly journals Identification of a soluble precursor complex essential for nuclear pore assembly in vitro

Chromosoma ◽  
1990 ◽  
Vol 100 (1) ◽  
pp. 56-66 ◽  
Author(s):  
Marie-Christine Dabauvalle ◽  
Karin Loos ◽  
Ulrich Scheer
Keyword(s):  
Nuclear Pore ◽  
Precursor Complex ◽  
Nuclear Pore Assembly

Electron-Transfer Reactions in Non-Aqueous Media. V. Solvent Effects in the Reduction of CoN3(NH3)52+ by Iron(II)

1979 ◽  
Vol 32 (10) ◽  
pp. 2139 ◽  
Author(s):  
TJ Westcott ◽  
DW Watts
Keyword(s):  
Electron Transfer ◽  
Aqueous Media ◽  
Activation Parameters ◽  
Transfer Reactions ◽  
Tetrahedral Coordination ◽  
First Order ◽  
Precursor Complex ◽  
Stage Process ◽  
Pseudo First Order ◽  
Reversible Formation

The reduction of CoN3(NH3)52+ by iron(II) is rate-determined by a two-stage process involving the reversible formation of an azide-bridged precursor complex prior to electron transfer in each of the solvents water, Me2SO, aqueous Me2SO and HCONMe2. The activation parameters in H2O and Me2SO, and the trends shown with increasing Me2SO concentrations in aqueous Me2SO, are similar to the properties of the previously studied CoCl(NH3)52+ and CoBr(NH3)52+ systems and contrast with the reduction of COF(NH3)52+. The results are consistent with a bridged precursor complex octahedral at both the iron and cobalt atoms in water but with tetrahedral coordination about the iron in Me2SO. In HCONMe2, as in the reduction of COF(NH3)52+, COCl(NH3)52+ and COBr(NH3)52+, the precursor complex is a significant part of the reacting solutions, and as a result the experimental pseudo-first-order rate constants for the loss of CoIII are not linearly dependent on the concentration of FeII. The initial spectra of the reacting solutions in this system also indicate significant concentrations of the precursor complex.

Synthesis of Copper Sulfide Nanoparticles by Thermal Decomposition Approach and Morphology Dependent Peroxidase-Like Activity

2020 ◽  
Vol 20 (5) ◽  
pp. 2763-2780
Author(s):  
Vanita Sharma ◽  
P. Jeevanandam
Keyword(s):  
Thermal Decomposition ◽  
Ethylene Glycol ◽  
Copper Sulfide ◽  
Diphenyl Ether ◽  
Decomposition Approach ◽  
Precursor Complex ◽  
Exposed Facets

Copper sulfide nanoparticles have been employed as artificial mimics for peroxidase-like activity. In the present study, copper sulfide nanoparticles with four different morphologies have been synthesized by thermal decomposition of cyclo-tri-μ-thioacetamide-tris(chlorocopper(I)) complex ([Cu3TAA3Cl3]) at 200 °C in different solvents such as diphenyl ether, ethylene glycol, 1-octadecene and also without any solvent. Hierarchical copper sulfide nanostructures are formed when the complex is decomposed in the absence of solvent, in diphenyl ether, and 1-octadecene while in the case of ethylene glycol, randomly agglomerated nanoparticles are formed. The precursor complex ([Cu3TAA3Cl3]) as well as copper sulfide nanoparticles were characterized using an array of techniques and after characterization, the peroxidase-like activity of copper sulfide nanoparticles was investigated.Morphologically different copper sulfide nanoparticles possess different exposed facets and due to this, the peroxidase-like activity was different among different morphologies.

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